Beral Coatings
Joe Blow
"Beral" coating. I like the low cost and slightly better
reflectivity, but I'm weary because H.L. Clausing is quick to
admit that it is not an aluminum coating and is much more
durable. Will this cause problems down the road? Specifically,
does it make the mirror more difficult to strip for future
recoatings? Are there any pitting concerns? How is Clausing's
service? Thanks.
Got questions? Get answers over the phone at Keen.com.
Up to 100 minutes free!
http://www.keen.com
John Ford
> reflectivity, but I'm weary because H.L. Clausing is quick to
> admit that it is not an aluminum coating and is much more
> durable. Will this cause problems down the road? Specifically,
> does it make the mirror more difficult to strip for future
> recoatings? Are there any pitting concerns? How is Clausing's
> service? Thanks.
Beral is/has been the standard supplier of coatings for Telescope
Engineering Company in Boulder, CO. They make (very!)high quality,
premium scopes.
You might discuss the technical merits of Beral coatings with them;
they are very personable people.
--
Clear skies,
John Ford
South-Eastern Michigan
jf...@inac.net
Sent via Deja.com http://www.deja.com/
Before you buy.
JMc
> Will this cause problems down the road? Specifically,
> does it make the mirror more difficult to strip for future
> recoatings?
No, Beral is a metal coating, so it can be stripped off later with
standard chemicals.
> Are there any pitting concerns? How is Clausing's
> service?
I've had several mirrors coated by Clausing - they are professionals and
do a good job.
Jim McSheehy
wsn...@gateway.net
second hardest substance known next to dimonds. Rubies are beral as are
emerals.
Bill
JMc
You are way off the mark here - Beral is definitely a metal coating.
From the Clausing web site ( http://www.clausing.com/beral.html ):
Beral is a hard metallic coating for front surface mirrors. Its
reflective properties are quite similar to those of Aluminum. The
average reflectance is 91% in the visible spectrum ( 400 nm to 700 nm.).
Beral is much harder than pure Aluminum and can be easily cleaned and
maintained. Beral was developed exclusively by H. L. Clausing Inc. for
use on astronomical telescope mirrors.
Jim McSheehy
Clive Gibbons
>Beral is not a reflective coating it is a protective coating. It is the
>second hardest substance known next to dimonds. Rubies are beral as are
>emerals.
Hi Bill.
I think your confusing Beral (tm) with beryl. Beryl (the mineral) is a
very hard substance. Beral (the proprietory coating) is mostly aluminum,
with a small amount of "something else" alloyed to add toughness and
slightly increase reflectivity.
Cheers,
--
Clive Gibbons
Technician, McMaster University,
School of Geography and Geology.
Chris1011
You are way off the mark here - Beral is definitely a metal coating.
From the Clausing web site ( http://www.clausing.com/beral.html ):
Beral is a hard metallic coating for front surface mirrors.>>
Do you believe everything you read? Beral coatings are simply aluminum with a
hard layer of oxide on top to prevent scratching during cleaning. By the way,
the reflectivity of Beral may hit 91% at a certain point in the wavelength
range, but the average reflectivity is only 88%, same as overcoated aluminum.
Roland Christen
ASTRO-PHYSICS
JMc
advertising for over 50 years? Pure aluminum develops an oxide layer
naturally, but that oxide layer does nothing to enhance its durability
as a coating. The problem when cleaning is not the overcoat, it's the
softness of the underlying aluminum.
I've had several Beral mirrors, and it's more resistant to sleeks than
aluminum w/SiO2. One 6" mirror was stored for 20 years (over ten in a
hot/cold attic), and when I unwrapped it, the Beral coating was still perfect
Jim McSheehy
ed_an...@my-deja.com
bg1.aol.com>,
chri...@aol.com (Chris1011) wrote:
> Do you believe everything you read? Beral coatings are simply aluminum with a
> hard layer of oxide on top to prevent scratching during cleaning. By the way,
> the reflectivity of Beral may hit 91% at a certain point in the wavelength
> range, but the average reflectivity is only 88%, same as overcoated aluminum.
>
> Roland Christen
> ASTRO-PHYSICS
>
Do you believe everything you write?
Beral coating is single layer coatings of alloy of two metals
- Al+Berillium. And it is the best coating for precision
optics, thanks to its uniformity.
Yuri
ed_an...@my-deja.com
gibb...@mcmail.cis.McMaster.CA (Clive Gibbons)
wrote:
> Hi Bill.
> I think your confusing Beral (tm) with beryl. Beryl (the mineral) is a
> very hard substance. Beral (the proprietory coating) is mostly aluminum,
> with a small amount of "something else" alloyed to add toughness and
> slightly increase reflectivity.
> Cheers,
> Clive Gibbons
"something else" is a few magic words known only to
opticians from Clausing!
Chris1011
Beral coating is single layer coatings of alloy of two metals
- Al+Berillium. And it is the best coating for precision
optics, thanks to its uniformity.
Yuri
>>
Mostly aluminum with beryllium overcoat. All the guys around here have it done
at Clausing because you can drive it in. We all know what he does. I have
several mirrors with the stuff. Not very impressive. Wally has his 16" coated
there, it lasts about 6 months before it looks bad. My test flat is Beral. It
never sees the outside but looks lousy after 6 years. It was cheap coating,
though.
Roland Christen
Jeff
jeff...@my-deja.com
He he. Just take it out in the humidity and see it vanish!
Jeff
In article <39593ED9...@my-deja.com>,
JMc <tri...@my-deja.com> wrote:
> Are you claiming that the folks at Clausing have been lying in their
> advertising for over 50 years? Pure aluminum develops an oxide layer
> naturally, but that oxide layer does nothing to enhance its durability
> as a coating. The problem when cleaning is not the overcoat, it's the
> softness of the underlying aluminum.
>
> I've had several Beral mirrors, and it's more resistant to sleeks than
> aluminum w/SiO2. One 6" mirror was stored for 20 years (over ten in a
> hot/cold attic), and when I unwrapped it, the Beral coating was still
perfect
>
> Jim McSheehy
>
> > Chris1011 wrote:
> >
> > >>
> > You are way off the mark here - Beral is definitely a metal coating.
> >
> > From the Clausing web site ( http://www.clausing.com/beral.html ):
> >
> > Beral is a hard metallic coating for front surface mirrors.>>
> >
> > Do you believe everything you read? Beral coatings are simply
aluminum with a
> > hard layer of oxide on top to prevent scratching during cleaning. By
the way,
> > the reflectivity of Beral may hit 91% at a certain point in the
wavelength
> > range, but the average reflectivity is only 88%, same as overcoated
aluminum.
> >
> > Roland Christen
> > ASTRO-PHYSICS
>
JMc
Are you making this stuff up as you go along? Beryllium front surface
mirrors are only useful at infrared wavelengths (> 1 micron). An
"overcoat" of Beryllium would make a very poor astro mirror. I'm sorry
you don't care much for Clausing or its services, but spare us the B.S.
Jim McSheehy
Chris1011
you don't care much for Clausing or its services, but spare us the B.S.
Jim McSheehy>>
You really believe that these coatings are superior reflectivity? Why then does
no one else do this? I have several Clausing mirrors in my shop, there are
quite a few mirrors in the area including our club 12" which has been coated by
Clausing a number of times. The coatings are softer than those that have oxide
multi-coatings applied. They certainly will show sleeks if not very very
carefully cleaned. None of these mirrors have what I would call enhanced
reflectivity. As far as durability, several of them have turned dark. Perhaps
it is our humidity, which can approach 100% in the summer.
I never considered this coating as anything but an inexpensive run of the mill
amateur mirror coating.
Roland Christen
ASTRO-PHYSICS
Jeff
Clausing lasted three weeks and pitted, sleeked, and powered up. No
fun observing with hazy images......
The last coating I got from them, the mirror ended up in the trash
can.
Jeff
Mike Barrs
news:20000627223540...@ng-fd1.aol.com...
> >>Do you believe everything you write?
> Beral coating is single layer coatings of alloy of two metals
> - Al+Berillium. And it is the best coating for precision
> optics, thanks to its uniformity.
> Yuri
> >>
>
> around here have it done at Clausing because you can drive
> it in. We all know what he does. I have several mirrors with
> the stuff. Not very impressive. Wally has his 16" coated
> there, it lasts about 6 months before it looks bad. My test flat
> is Beral. It never sees the outside but looks lousy after 6 years.
> It was cheap coating, though.
Hi Roland,
Okay, you don't like Clausing coatings that much, so what company would you
recommend to coat a Newtonian mirror, preferably a large one (say, up to
24")? Assume the customer wouldn't mind paying more than usual for a high
quality coating.
With QSP selling their business and Spectrum hard to reach (they don't do
over 22" anyway), it seems that our choices for mirror coatings are getting
a little restricted lately. It would be nice to hear about a few more
suppliers of high quality coatings.
Mike Barrs
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WHALEN44
I have Beral on my mirrors, and live in humidity central, observe 50' from salt
water, and no problems. Coatings still look new.
Richard Whalen
whal...@aol.com
"Time spent observing the heavens is not deducted from your lifespan"
The Beast
cecr...@NOWORMS.gte.net wrote:
> I agree with Roland much-o. The last coat a friend of mine had from
> Clausing lasted three weeks and pitted, sleeked, and powered up. No
> fun observing with hazy images......
> The last coating I got from them, the mirror ended up in the trash
> can.
>
> Jeff
>
>
observatory started to tarnish (turned brown) wothin 6 months. Same
goes for the 17" north of Tampa at that club's spot.
NOW, someone, we _really_ need to know where to get a 90%+ coating.
Last we heard here, the "enhanced" coatings caused scatter problems.
True???
-----------------------------------------------------------------
The Beast Appears In Darkest Nights,
Astronomers Gather At Their Sites,
And When They Trod Upon The Grass,
The Beast Will Come To Kick Their Scopes and Eyepieces and Stuff.
Jeff
Florida. To each his or her own. Or is that owner :)
Jeff
Axel
standard line of mirrors. These are hardly run-of-the-mill mirrors,
rather considered to be some of the best professional optics out
there. A mirror-maker who charges $1000-$1500 for a medium-sized
mirror is not going to endorse a "run-of-the-mill amateur mirror
coating."
The big names Galaxy and Pegasus have their own opinions on coating
procedures. Galaxy uses their own Enhanced Aluminum with dielectrics
whereas Pegasus disavows enhanced coatings
(www.icstars.com/pegasus/FAQ.htm) and sticks with standard Aluminum,
using Spectrum for smaller mirrors and United Lens or Clausing for
bigger ones. Anyone know what Carl Zambuto likes???
The bottom line is that everyone has different opinions, but Clausing
has proven itself as a reliable mirror coater and wouldn't have
remained in business for over 70 years if they didn't maintain their
reputation with quality coatings!
I ordered Beral on my Royce 8" f/6 and am expecting delivery in a
couple weeks!
Ritesh
In article <20000628100015...@ng-fs1.aol.com>,
jar...@my-deja.com
"Mike Barrs" <mba...@NOSPAM.mangonet.com> wrote:
>
> With QSP selling their business and Spectrum hard to reach (they
don't do
> over 22" anyway), it seems that our choices for mirror coatings are
getting
> a little restricted lately. It would be nice to hear about a few more
> suppliers of high quality coatings.
>
> Mike Barrs
>
Diego. It lasted about 2 years, after which it was definitely showing
signs of tarnish (I don't know if it was the humidity, salt in the air,
or pullution from Tijuana and LA that caused it). I had the mirror
recoated with an enhanced coating by Precision Applied Products in LA.
I picked them because they promised 2 week turn-around vs. QSP saying
at the time they ahd a 6-10 week turn-around. I was very pleased with
the mirror coating (granted, while the mirror was out I also made some
improvements on the OTA, applying sawdust and black paint to the
interior, etc.). They recoated the diagonal at the same time for free.
They used to advertise in S&T, not sure if they still do. Seemed like a
smaller shop, but they did a good job for me.
I know some people have had concern about enhanced coatings,
especially on larger mirrors (my 18" Starmaster has standard coatings).
I don't know if these guys do a better job than others, if a 10" mirror
is easier to put a smooth coating on, or if I just got lucky. I believe
Rick Singmaster said that he was having problems on some of his large
mirrors with enhanced coatings, and felt a good coating was a hit-or-
miss thing. If you're willing to send it in, test it, and re-coat it if
necessary, you can probably get a good enhanced coating on any mirror.
Think of it sort of like buying a scope from Meade or Celestron - they
make some very good ones, but you may have to return a few lemons
first.... ;-).
Jarad Schiffer
Rockett Crawford
What do you think about the reflectivity of these coatings? Do you
know the percentage of reflectivity?
Rockett
WHALEN44 wrote:
> Hi Jeff,
>
> I have Beral on my mirrors, and live in humidity central, observe 50' from salt
> water, and no problems. Coatings still look new.
----------------------------------------------------------------------------
Capella's Observatory (CCD Imaging)
http://web2.airmail.net/capella
Howard Lester
Howard Lester
Jeff
like it must have started rusting :))))))))))))))))))) !
Jeff
On Wed, 28 Jun 2000 14:57:17 GMT, The Beast <elbe...@my-deja.com>
wrote:
Jeff
to speak, I put a silver coat on one of my mirrors about ten years ago
and had someone apply SiO overcoat to it (in a vacuum bell) ands it
only tarnished about a year ago. The edges began to turn a bit black
after that.
Jeff
Jeff
trheads turn nasty when names are mentoned. Be as it may, or such,
the person(s) who experienced this was/were not happy about removing
that heavy 16-inch mirror and cell from his 16-inch f/6 Newtonian, or
that other person(s) who wan not happy about removing that lighter
12.5-inch mirror and cell, and the other person(2) with that 14-inch
Newtonian, and some guy with that 20-inch from up north who found
scratches in the glass and pits in the Beral, and me, when I
discovered my 12.5-inch f.30 Cass had not fours diffraction spikes,
but three more. Then we all had to find a coating service to boot.
Never found any theory why I had three diffaction-like spikes!
Wonders will never cease. That's nearly as bad as a triangular image!
JMc
The largest mirrors AP regularly coats are about 60 mm wide, so why are
you asking Roland Christen for advice? H. L. Clausing has been coating
telescope mirrors longer than Roland has been alive. They haven't
remained in business for 73 years because they don't know what they're
doing. I'm just amazed at the misinformation and sheer B.S. that gets
thrown around on saa by people that should know better.
Jim McSheehy
Jeff
Jeff
Jeff
remember correctly. Time flies when you're having fun.
Jeff
On Tue, 27 Jun 2000 20:01:41 GMT, wsn...@gateway.net wrote:
>Beral is not a reflective coating it is a protective coating. It is the
>second hardest substance known next to dimonds. Rubies are beral as are
>emerals.
>Bill
>
>
Howard Lester
H.L. (Howard Lester)
WHALEN44
They seem fine, I would guess around the same as standard aluminum w/overcoat.
For sure not an "enhanced" coating. They do seem to have less scatter than
standard aluminum, but hard to tell for sure.
WHALEN44
What 17" are you refering to? Are you talking about Hickory Hill?
Rockett Crawford
WHALEN44 wrote:
> Hi Rockett,
>
> They seem fine, I would guess around the same as standard aluminum w/overcoat.
> For sure not an "enhanced" coating. They do seem to have less scatter than
> standard aluminum, but hard to tell for sure.
Thanks Richard,
Rockett
Howard Lester
all these refractor manufacturers to make more of them in
order to take the load off my son P.A., who has been inundated
with orders for more coatings.
H.L.
Jeff
Lester 8-) You know you're alive....
Jeff
"Howard Lester" <hle...@as.arizona.edu> wrote in message
news:395A2D0B...@as.arizona.edu...
Valentine Germann
As have a lot of folks in the Midwest, I've had several mirrors
coated by Clausing. Our club scopes, capped and sitting in
roll-off observatories, have needed re-coating within five or
six years. though we usually have waited longer than that to
pull the trigger on sending them in again.
One mirror in my possession was coated by Clausing about
20 years ago and has been taped up in a box since that time.
(It's a long story.) Anyway, that coating is still serviceable and
the mirror was recently unpacked and has been in use for about
a week now. We'll see how long the coating lasts out in the air!
Clausing coatings are relatively soft compared to anything
with a real overcoat. Back in1982, I bought an 8-inch mirror
from Telescopics that had, I think, a Pancro (?) coating on it,
with a quartz overcoat, so it was said. That mirror has been
very indifferently treated (by others) over the years but the
coating was still VERY bright in 1997 -- and it had no sleeks
even though it had been cleaned a lot. A six-inch mirror I had
coated by Clausing at that time has been re-coated twice
since then! C'est la vie!
I had a 10-inch mirror done by QSP a couple of years ago
and they did a great job on the enhanced coatings, though the
price was, of course, several times what Clausing charges
for Beral. This mirror is now MUCH brighter now than it was
with Clausing coatings, even when new.
I have never had a Clausing coating "fall apart" right away,
ever, though it seems that about five years is the true serivce
life of the surface.
Val Germann
Central Missouri Astronomical Association
Columbia, Missouri
JMc
Henry Ford died some time ago too. Last I heard HIS COMPANY still makes cars.
Jim McSheehy
> Jeff wrote:
>
> Actually, H.L. passed away some a decade ago or so, maybe less.
>
The Beast
whal...@aol.com (WHALEN44) wrote:
> Beast,
>
> What 17" are you refering to? Are you talking about Hickory Hill?
>
> Richard Whalen
> whal...@aol.com
>
>
-----------------------------------------------------------------
The Beast Appears In Darkest Nights,
Astronomers Gather At Their Sites,
And When They Trod Upon The Grass,
The Beast Will Come To Kick Their Scopes and Eyepieces and Stuff.
Chris1011
The largest mirrors AP regularly coats are about 60 mm wide, so why are
you asking Roland Christen for advice? H. L. Clausing has been coating
telescope mirrors longer than Roland has been alive. They haven't
remained in business for 73 years because they don't know what they're
doing. I'm just amazed at the misinformation and sheer B.S. that gets
thrown around on saa by people that should know better.
Jim McSheehy >>
I don't know where you got that from. The largest mirrors I have coated are
10". I have had dozens of 6", 7" and 8" mirrors coated. I have used Clausing
only on a couple of internal flats (one of which has turned brown). For all my
customer mirrors I use a professional coater who has large Ebeam machines. I
would NEVER use Clausing mirrors in any customer scope. My choice, my opinion.
Roland Christen
ASTRO-PHYSICS
star...@infomagic.net
I went with Spectrum even though they certainly are hard to
reach. They have a fairly good web page that will tell you just
about all you wanted to know anyway. They charge $10 per inch
for 96% EAL (enhanced aluminum). Just send them the mirror.
They will do a very professional job.
I had my 18 in. f/5.5 Swayze mirror coated with 96% EAL
from Spectrum. The coating I got was immaculate without
any pits, scatches, or chips on the edge of the mirror. They took
really great care in packing it too. The images are superb both
because of Swayze's quality and lack of scattering from the coating.
The images are very high contrast. Even bright stars and planets
show no halo or a "nebula" or smearing of light around the images
except around Merope in the Pleiades et al where there actually is
a nebula surrounding the stars.
In my opinion the varible results people have been getting with EAL
type coatings whether from QSP, Spectrum, PAP, or whatever is
not due to the incompetence or shoddy workmanship of the coating
company. It is, IMHO, the result of mirrors lacking a smooth figure
to start with. Some may even have been under polished when they
were sent to be coated. A rough, non smooth surface is still going
to scatter light after getting coated. I know what some of you are
probably thinking. No, the coatings had variable thickness and were
not uniformly applied. I read the SAA posts on the effects of EAL last
year and that was a common concensus. I am not trying to beat that
dead horse again. However, I went against the commonly held opinion
on EAL and all turned out well for me.
Mike Barrs wrote:
> Chris1011 <chri...@aol.com> wrote in message
> news:20000627223540...@ng-fd1.aol.com...
> > >>Do you believe everything you write?
> > Beral coating is single layer coatings of alloy of two metals
> > - Al+Berillium. And it is the best coating for precision
> > optics, thanks to its uniformity.
> > Yuri
> > >>
> >
> > Mostly aluminum with beryllium overcoat. All the guys
> > around here have it done at Clausing because you can drive
> > it in. We all know what he does. I have several mirrors with
> > the stuff. Not very impressive. Wally has his 16" coated
> > there, it lasts about 6 months before it looks bad. My test flat
> > is Beral. It never sees the outside but looks lousy after 6 years.
> > It was cheap coating, though.
>
> Hi Roland,
>
> Okay, you don't like Clausing coatings that much, so what company would you
> recommend to coat a Newtonian mirror, preferably a large one (say, up to
> 24")? Assume the customer wouldn't mind paying more than usual for a high
> quality coating.
>
> With QSP selling their business and Spectrum hard to reach (they don't do
> over 22" anyway), it seems that our choices for mirror coatings are getting
> a little restricted lately. It would be nice to hear about a few more
> suppliers of high quality coatings.
>
> Mike Barrs
>
Howard Lester
"Spectrum" headings out there.)
Howard Lester
Howard Lester
http://www.spectrum-coatings.com
Jeff
magazies with all those ads. WHAT WIIIILL we do!
Jeff
.
On Wed, 28 Jun 2000 14:19:31 -0400, JMc <tri...@my-deja.com> wrote:
>H.L. Clausing (Inc.) also happens to be the name of the company - duh.
>Henry Ford died some time ago too. Last I heard HIS COMPANY still makes cars.
>
>Jim McSheehy
>
>> Jeff wrote:
>>
>> Actually, H.L. passed away some a decade ago or so, maybe less.
>>
>> Jeff
>> On Wed, 28 Jun 2000 12:13:34 -0400, JMc <tri...@my-deja.com> wrote:
>>
>> >Howard,
>> >
>> >The largest mirrors AP regularly coats are about 60 mm wide, so why are
>> >you asking Roland Christen for advice? H. L. Clausing has been coating
>> >telescope mirrors longer than Roland has been alive. They haven't
>> >remained in business for 73 years because they don't know what they're
>> >doing. I'm just amazed at the misinformation and sheer B.S. that gets
>> >thrown around on saa by people that should know better.
>> >
>> >Jim McSheehy
>> >
Greg Campbell
Howard Lester wrote:
> And Spectrum's web site is... ? (Doing a search, I found a million
> "Spectrum" headings out there.)
http://www.spectrum-coatings.com/
===========
Note!
Anti-spam tactics engaged!
Remove the duplicate "g" and "s" before replying.
ed_an...@my-deja.com
fd1.aol.com>,
chri...@aol.com (Chris1011) wrote:
> Mostly aluminum with beryllium overcoat. It was cheap coating,
> though.
> Roland Christen
I was talking today with one of the Clausing owners and
ansked some question about Beral coating.
It is ONE LAYER coating, but there is no Berillium in the
alloy 9I was mistaken). Alloy has three components (Al is
the major one).
The name BERAL came from the earliest (50-60years old)
alloys, which were replaced by better once, but the trade
name was left the same.
Yes, it is cheaper, and BTW is more uniform, and nas less
skatter than any multi layer Enhanced coatings. Of cource it
is important only for precision mirrors.
One more things to know, the Beral coating is sensitive to
environment - if people around hate it - it bacomes gray.
Yuri.
WHALEN44
I was not aware they had a 17" up there. I thought it was an old 16". Are you
talking about Dave R. old scope?
Evan Miller
>
> Chris1011 <chri...@aol.com> wrote in message
> news:20000627223540...@ng-fd1.aol.com...
> > >>Do you believe everything you write?
> > Beral coating is single layer coatings of alloy of two metals
> > - Al+Berillium. And it is the best coating for precision
> > optics, thanks to its uniformity.
> > Yuri
> > >>
> >
> > Mostly aluminum with beryllium overcoat. All the guys
> > around here have it done at Clausing because you can drive
> > it in. We all know what he does. I have several mirrors with
> > the stuff. Not very impressive. Wally has his 16" coated
> > there, it lasts about 6 months before it looks bad. My test flat
> > is Beral. It never sees the outside but looks lousy after 6 years.
>
>
> Okay, you don't like Clausing coatings that much, so what company would you
> recommend to coat a Newtonian mirror, preferably a large one (say, up to
> 24")? Assume the customer wouldn't mind paying more than usual for a high
> quality coating.
>
> With QSP selling their business and Spectrum hard to reach (they don't do
> over 22" anyway), it seems that our choices for mirror coatings are getting
> a little restricted lately. It would be nice to hear about a few more
> suppliers of high quality coatings.
>
> Mike Barrs
>
> -----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
> http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
> -----== Over 80,000 Newsgroups - 16 Different Servers! =-----
Some years ago I had some mirrors recoated by Evaporated Metal Films of
Ithaca, NY. They had many types of coatings available and the quality
was superb, but I don't know what services they still offer.
Evan Miller
Dan Chaffee
Val Germann wrote:
> have never had a Clausing coating "fall apart" right away,
> ever, though it seems that about five years is the true serivce
>life of the surface.
I have. I'm just north of KC MO, and have received mirrors fresh out
of the shipping box from Clausing that were pitted and had blotchy
shorelines all over hell. One of my diagonals he coated flaked off
at the edge within a month. My mirrors look like crap in one year
after his touch. I had a great coating from Evaporated Metals that
showed none of the defects of the vaunted beral coating. I do lots of
observing and the dewpoints here in Missouri are often as high
as those on the gulf (70 deg. f. plus). Quite an assault on a mirror,
not to mention the profusion of resinous trees in the neighborhood.
These coatings are cheap and you get what you pay for.
Sending mirrors out to be coated is risky and the fewer times
you do it, the better; so I've come to the conclusion that these
chinsy coatings are false economy. (And this is from a case-
hardened penny-pincher:-)
Dan Chaffee
The Beast
whal...@aol.com (WHALEN44) wrote:
> Beast,
>
> I was not aware they had a 17" up there. I thought it was an old 16".
Are you
> talking about Dave R. old scope?
>
> Richard Whalen
> whal...@aol.com
>
>
think) a 17". It might be a 14", but I know it is f/4 and tarnishing.
One of the guys did make a 17" or 17.5" Dob with a monster secondary.
The views are Ok, but the mount is WAY too unstable to hold collimation
or sometimes even to focus. Unless it is new, there is no 16" up there.
-----------------------------------------------------------------
The Beast Appears In Darkest Nights,
Astronomers Gather At Their Sites,
And When They Trod Upon The Grass,
The Beast Will Come To Kick Their Scopes and Eyepieces and Stuff.
mjc5
is indeed a very hard substance. Beral is a proprietary metal compostion
applied to mirrors by Clausing. Nice coating, and ecomomical also.
- Mike -
wsn...@gateway.net wrote:
>
> Beral is not a reflective coating it is a protective coating. It is the
> second hardest substance known next to dimonds. Rubies are beral as are
> emerals.
> Bill
>
mjc5
Can you confirm that it is an overcoat process? It was my impression,
and appears to be, a single coating, that strips readily in cleaning
with ferric chloride. Overcoated mirrors usually are a lot harder to
strip. Perhaps the overcoat in this case is readily dissolvable.
In any event, if it is an overcoat process, they are offering it very
inexpensively considering the extra steps.
- Mike
Chris1011 wrote:
>
> >>
> You are way off the mark here - Beral is definitely a metal coating.
>
> From the Clausing web site ( http://www.clausing.com/beral.html ):
>
> Beral is a hard metallic coating for front surface mirrors.>>
>
> Do you believe everything you read? Beral coatings are simply aluminum with a
> hard layer of oxide on top to prevent scratching during cleaning. By the way,
> the reflectivity of Beral may hit 91% at a certain point in the wavelength
> range, but the average reflectivity is only 88%, same as overcoated aluminum.
>
> Roland Christen
> ASTRO-PHYSICS
mjc5
Is the beryllium overcoat transparent? I'm a bit confused here because
if it isn't transparent, it's really a beryllium mirror on an AL substrate.
Chris1011 wrote:
> Mostly aluminum with beryllium overcoat. All the guys around here have it done
> at Clausing because you can drive it in. We all know what he does. I have
> several mirrors with the stuff. Not very impressive. Wally has his 16" coated
> there, it lasts about 6 months before it looks bad. My test flat is Beral. It
> never sees the outside but looks lousy after 6 years. It was cheap coating,
> though.
>
> Roland Christen
pro...@my-deja.com
Joe Blow <mike_neu...@my-dejanews.com.invalid> wrote:
> I'm thinking of having my mirror recoated using H.L. Clausing's
> "Beral" coating. I like the low cost and slightly better
> reflectivity, but I'm weary because H.L. Clausing is quick to
> admit that it is not an aluminum coating and is much more
> durable. Will this cause problems down the road? Specifically,
> does it make the mirror more difficult to strip for future
> recoatings? Are there any pitting concerns? How is Clausing's
> service? Thanks.
I have to agree with Roland. They are popular in the Chicagoland area
for obvious proximity reasons. However, in the real world of actual 'in
the field' observing, their durability is somewhat lacking, especially
in the midwest where moisture is common. You would be far better off
with an overcoated aluminum coating. Of course your other alternative
is having Clausing recoat your mirror more frequently as Beral coatings
are usually quite affordable. For I though, phewwy..especially if you
have a larger mirror, every time you extract and reinstall the mirror
in your telescope, you run the chance of damaging it; not good. I
prefer the once every 5 years idea of having a more durable/expensive
coating applied. In the end it's up to you of course as both coatings
initially perform well. You can also extend the life of your mirror's
coating by learning how to clean it regulary and PROPERLY, also by
protecting it from dew and condensation.
Paul R.
>
> Got questions? Get answers over the phone at Keen.com.
> Up to 100 minutes free!
> http://www.keen.com
Del Johnson
me to believe Roland. He has no reason to falsify information as he is
not in the coating business. You don't come across as being objective,
Jim, as you simply disregard the numerous user reports.
Del Johnson
In article <395A23FC...@my-deja.com>,
JMc <tri...@my-deja.com> wrote:
> Howard,
>
> The largest mirrors AP regularly coats are about 60 mm wide, so why
are
> you asking Roland Christen for advice? H. L. Clausing has been coating
> telescope mirrors longer than Roland has been alive. They haven't
> remained in business for 73 years because they don't know what they're
> doing. I'm just amazed at the misinformation and sheer B.S. that gets
> thrown around on saa by people that should know better.
>
> Jim McSheehy
>
Del Johnson
substrate, as the mirrors performed better after being recoated. What
was said was that a portion (about a third,I believe) of large mirrors
have problems with enhancd coatings. The others were just fine.
Del Johnson
In article <395A692D...@infomagic.net>,
star...@infomagic.net wrote:
> Mike,
>
>
> In my opinion the varible results people have been getting with EAL
> type coatings whether from QSP, Spectrum, PAP, or whatever is
> not due to the incompetence or shoddy workmanship of the coating
> company. It is, IMHO, the result of mirrors lacking a smooth figure
> to start with. Some may even have been under polished when they
> were sent to be coated. A rough, non smooth surface is still going
> to scatter light after getting coated. I know what some of you are
> probably thinking. No, the coatings had variable thickness and were
> not uniformly applied. I read the SAA posts on the effects of EAL
last
> year and that was a common concensus. I am not trying to beat that
> dead horse again. However, I went against the commonly held opinion
> on EAL and all turned out well for me.
>
WHALEN44
Unless they swapped out scopes, the scope in the dome is Dave Raden's old
scope that was donated when he passed away a few years back. I believe the
coatings are about 15 years old, unless the club had them redone in the last
two years.
I will make a few phone calls and report back.
Jeff
Jeff
"WHALEN44" <whal...@aol.com> wrote in message
news:20000629122241...@ng-cl1.aol.com...
Axel
Clausing that Roland and the other four or five shared had, then
Clausing would have gone bankrupt 30 years ago due to a lousy
reputation!
Tasco survives based on sheer ignorance of the mass public! But
Clausing can't do that because people who buy metal coatings are
generally very knowledgable and the word spreads quickly in a niche
market.
My opinion is that these people who had bad experiences were somehow
subjecting the mirrors to rare conditions (perhaps unknowingly) that
the Clausing coatings were never designed to withstand. Coatings
turning brown in less than a year point to a serious problem with the
environment in the area (coal-fired power plants?) and maybe forgetting
to put shower caps on the ends of the tubes!!!?? These cases are
definitely in the vast minority, otherwise Clausing would have been
laughed out of the coating business years ago.
In article <8jftt8$gsj$1...@nnrp1.deja.com>,
Jeff
tubs, or something :) Anyone know how one goes about anodizing a mirror?
Jeff
"mjc5" <mj...@psu.edu> wrote in message news:395B67C5...@psu.edu...
> There is a bit of confusion here. The beryl (spelled differently also)
> is indeed a very hard substance. Beral is a proprietary metal compostion
> applied to mirrors by Clausing. Nice coating, and ecomomical also.
>
> - Mike -
>
> wsn...@gateway.net wrote:
> >
> > Beral is not a reflective coating it is a protective coating. It is the
> > second hardest substance known next to dimonds. Rubies are beral as are
> > emerals.
> > Bill
> >
Jeff
their coatings. With the salty air, auto emissions, swimming pool vapors,
lye vapors for mall the grave sites, and so on - it would seem that any coat
would not last long. However, my last E&W coat is still shinny and nice on
my 16-inch after 12 years! My 12.5-inch turned a bit weird so I am looking
for some service now that QSP went down the tubes. They sold out most
likely because the address of the new company is the same as QSP's is. Was.
Wiz. Wuz.
Jeff
<pro...@my-deja.com> wrote in message news:8jfs1c$f7d$1...@nnrp1.deja.com...
Del Johnson
all. Even then, we are just a few out of the entire marketplace. You
would be surprised how long a poor product can survive. Take Bushnell
as an example.
My understanding is that the Beral coating is not SiOx overcoated,
which has a lot to do with environmental resistance.
Del Johnson
In article <8jfuts$hr1$1...@nnrp1.deja.com>,
Clive Gibbons
Axel <rites...@hotmail.com> wrote:
>Jim's point is simply that if everyone had as bad experiences with
>Clausing that Roland and the other four or five shared had, then
>Clausing would have gone bankrupt 30 years ago due to a lousy
>reputation!
I'm sure some folks have had poor experiences with Clausing coatings.
However, I've sent 4 mirrors to them (granted, the last one was about 10
years ago), with no complaints.
My first mirror was an 8", sent in 1976. The Beral coating on it
is still in fine shape (no tarnish or flaking visible). It hasn't been
kept in a hermetically sealed jar, either... just in a cupboard for some
of it's life and in the scope the rest of the time. This is in southern
Ontario, BTW, which has it's share of pollution and humidity problems
in the summer months.
However, I do understand that more recently the Beral coating formula has
changed and the original operator passed away. Perhaps their work isn't as
trouble-free these days.
In any event, Beral coatings are still very inexpensive and for many, seem
to be a satisfactory performer.
Cheers,
--
Clive Gibbons
Technician, McMaster University,
School of Geography and Geology.
JMc
coatings per se. I was mainly responding to the obviously
false/misleading claims made about the Beral process by several posters:
1) It's not a metal
2) It's a Beryllium overcoat
3) It lasts for 6 months
4) The reflectivity is lower than regular aluminum
5) They've been lying in their advertising for 50 years
These are simply false, and I'm baffled why Roland would inject some of
these into this discussion because as you say, he's not even in the
coating business.
The first mirror I made as a 14 year old was coated by Clausing. The
edge wasn't fully polished out, and they returned it with a handwritten
note admonishing me to not be in such a hurry, and to spend more time
polishing the next one. Now I'm sure that some people have had a bad
experience with a Beral coating, but I've used it on four mirrors and
it's always been good. You can count on one hand the number of ATM
suppliers that have been in business as long as Clausing, and IMO, they
deserve some respect.
Jim McSheehy
WHALEN44
You make a good point. I have yet to hear of one coating company that never has
any complaints. I think they all let a few poor jobs slip out the door.
Another factor that must be taken into account is "how does that new coating
effect your mirrors wavefront quality"?
I have see good mirrors come back from the coaters with highly reflective
coatings, but ruined wavefronts. So what's a person to do?
Chris1011
In any event, if it is an overcoat process, they are offering it very
inexpensively considering the extra steps.
>>
I'm sure they overcoat it with something. Without some kind of overcoat, the
aluminum will pit rather quickly. (have you ever seen a Winnebago camper?)
Overcoating takes place in the same chamber and takes about one minute. It does
not add anything to the cost.
A multi-coated mirror starts out with an oxide layer on the bare glass,
followed by an aluminum layer, followed by several alternating layers of
different high and low index materials. All these layers require a multi-pocket
e-beam machine with very good control of the deposition rates. Usually, the
rate is crystal controlled with a computer determining the exact deposition
thickness. These type of coatings are extremely durable and can be cleaned
without picking up sleeks too easily. The layers are homogeneous and
effectively block moisture from the aluminum coating. A simple quartz or
silicon monoxide overcoat is somewhat porous, and can let moisture through to
the underlying aluminum coating.
To get the highest reflectivity, the design has to be carefully chosen for the
right thickness of the aluminum layer. It so happens that light impinging on an
aluminum layer actually penetrates a certain amount below the layer (in a
manner similar to an evanescent wave), and reflection does not occur at the
surface of the aluminum. Therefore, the type of underlying layer and it's
refractive index makes a difference in the final result. When properly done,
this type of coating will be more smooth than a normal overcoated aluminum
coating.
Roland Christen
ASTRO-PHYSICS
Chris1011
Jim's point is simply that if everyone had as bad experiences with
Clausing that Roland and the other four or five shared had, then
Clausing would have gone bankrupt 30 years ago due to a lousy
reputation!>>
And my point was that these are not fancy coatings like some people claim (read
my other post about what is a fancy coating). People around here (Chicago area)
use them because they are cheap, and they acknowledge that they are not the
best, and that the reflectivity is not high. Our club 12" has been coated and
recoated numerous times by Clausing, and the surface is now a mess due to the
number of strippings it has received by Clausing. The mirror was one of the
finest examples of a paraboloid by Carl Hand, a local ATM who made hundreds of
mirrors in his lifetime. It used to be an excellent planetary scope, but with
the surface etched and pitted now, the contrast is very poor. The mirror never
received a decent coating because there was never a desire to spend any money.
Now the mirror is beyond repair, and it is serving out it's existence as a
portable Dobsonian for public star parties and club events.
Roland Christen
ASTRO-PHYSICS
WHALEN44
Thanks for the information. So who do you recommend that has a "multi-pocket
e-beam machine with very good control of the deposition rates" ?.
Scott Rychnovsky
chri...@aol.com (Chris1011) wrote:
> A multi-coated mirror starts out with an oxide layer on the bare glass,
> followed by an aluminum layer, followed by several alternating layers of
multi-pocket
> e-beam machine with very good control of the deposition rates. Usually, the
> rate is crystal controlled with a computer determining the exact deposition
> thickness. These type of coatings are extremely durable and can be cleaned
> without picking up sleeks too easily. The layers are homogeneous and
> effectively block moisture from the aluminum coating. A simple quartz or
> silicon monoxide overcoat is somewhat porous, and can let moisture through to
> the underlying aluminum coating.
>
Roland,
What companies will apply enhanced caoting to telescope mirrors properly
using e-beam technology? Since you have already mentioned some companies by
name whose coating you do not recommend, why not mention some companies
that you do recommend?
Scott
--
Scott Rychnovsky
srychno...@uci.edu
TMBack
>I have see good mirrors come back from the coaters
>with highly reflective coatings, but ruined wavefronts.
>So what's a person to do?
Good point. The late Norm Oberly (a superb optician
who made the Warren Rupp quartz 31" f/7 mirror), always
was terribly anxious right after each time the mirror was
re-coated. The tension was thick as Norm would ride up
the Mite-E-Lift to star test the telescope with the new
coating. He would spend about 20 mins at the eyepiece,
and we held our breath. He wouldn't say a word until he
came down to floor level.
Well Norm, how is it?! And if a big smile was on his
face, would all knew that the coating was done right.
Then it was our turn to have fun, seeing fantastic detail
in deep-sky objects.
Thomas Back
TMB Optical
The Beast
whal...@aol.com (WHALEN44) wrote:
> Beast,
>
> Unless they swapped out scopes, the scope in the dome is Dave
Raden's old
> scope that was donated when he passed away a few years back. I
believe the
> coatings are about 15 years old, unless the club had them redone in
the last
> two years.
>
> I will make a few phone calls and report back.
>
> Richard Whalen
> whal...@aol.com
>
>
14.1", and they all say it is f/4, correct or not. AND, yes, it got a
new Clausing coating about 4-5 years ago.
----------------------------------------------------------------
The Beast Appears In Darkest Nights,
Astronomers Gather At Their Sites,
And When They Trod Upon The Grass,
The Beast Will Come To Kick Their Scopes and Eyepieces and Stuff.
TMBack
> My test flat is Beral. It never sees the outside but looks
>lousy after 6 years. It was cheap coating, though.
I've seen Roland's test flat with the Beral coating, and
it is indeed a little worse for wear (noticeable loss of
brightness compared to a new coating).
When I worked at Dobbins Instrument Company, we
had a bunch of mirrors coated by Clausing. I was never
impressed. The "sky" coloration test showed that the
reflectivity couldn't be greater than a regular aluminum
coating (~88%), and the amount of pinhole and other
defects were high. The mirrors that were coated by
Evaporated Metal, and PAP were always much cleaner,
brighter, and we never once had a complaint about
premature tarnishing.
Thomas Back
TMB Optical
Joe Ringer
>The first mirror I made as a 14 year old was coated by Clausing. The
>edge wasn't fully polished out, and they returned it with a handwritten
>note admonishing me to not be in such a hurry, and to spend more time
>polishing the next one. Now I'm sure that some people have had a bad
>experience with a Beral coating, but I've used it on four mirrors and
>it's always been good. You can count on one hand the number of ATM
>suppliers that have been in business as long as Clausing, and IMO, they
>deserve some respect.
>
>Jim McSheehy
When was this? Was it a 6" mirror?
--
clear skies, |http://www.erols.com/jringer3/astro1.htm
Joe |
|Remember when "Truth, Justice, & the American Way"
|wasn't contradictory?
WHALEN44
I keep telling these guys they shouldn't clean their mirrors with that english
ale, but they just won't listen :-)
>Turn brown! That didin't happened to me or the others but it sounds like it
must have started rusting>
Jeff
used to say, it'll rust your pipes. I could never reconcile all those
cowboys in Tombstone slurping down all that hard stuff! Man, they
would dry out like a bunch of prunes!
Am still looking for an alternative to QSP. Tippy, Don, and others
are highly satisfied with QSP's coatings, but with them down the tube,
so to speak, I'm not sure about sending my mirror to someone who has
just sold out their business. Probably safe but I think I'll check
into Spectrum down in Florida. Having heard plenty of rumors about
that business and finding out moist of it is B.S.; I usually take it
with a grain of salt. Sure don't need a bunged up mirror right before
I retire to the poor house. My 16-inch is still nie and bright, so it
will probably out last me.
Hey, that Mississippi Mud is good, it's a black & tan.......
Jeff
JMc
really helped out in the next football season. The coach assumed I was
lifting weights ;-)
>Joe Ringer wrote:
>
> >On Thu, 29 Jun 2000 13:49:50 -0400, JMc wrote:
> >
> >The first mirror I made as a 14 year old was coated by Clausing. The
> >edge wasn't fully polished out, and they returned it with a handwritten
> >note admonishing me to not be in such a hurry, and to spend more time
> >polishing the next one.
>
Tim Parker
JMc wrote:
> H.L. Clausing (Inc.) also happens to be the name of the company - duh.
> Henry Ford died some time ago too. Last I heard HIS COMPANY still makes cars.
Yeah, but they sure don't make them like they used to!!!
-Tim. 1929 Model A Ford (bone stock!!!)
Howard L. Clausing
I have never read so much mis-information in my life.
First if all rumors of my demise are somewhat premature. I am very
much alive and well, as is my company. It was my uncle who passed
away in October of 1981. You can be sure that the gentleman who said
I was dead is equally as well informed about my coatings.
It is one thing for amateurs to voice opinions in such a format as
this. In fact, I applaud it. Sharing and discussing ideas is vital
to science. But I am especially disappointed with comments made here
by Mr. Christen from ASTRO-PHYSICS. It is extremely unprofessional to
slam a competitor in a public forum. Especially when those comments
are totally baseless and untrue. Be assured my attorney will review
them for possible libel.
The facts are as follows:
Beral is indeed an alloy as stated on my web page.
Beral is priced competitively for the amateur market.
Beral is an excellent coating for a wide variety of applications,
including telescope mirrors.
Beral is not overcoated so humidity, moisture and acid precipitation
may be a problem in some geographic regions. We recommend Beral on
mirrors up to 16 inches. Smaller mirrors tend to be transportable, so
they are usually kept inside and exposed to less weathering.
We make no guarantee on the length of service of any of our coatings.
I don't know of any coater who does. It's hard to guarantee something
that is 15/1,000,000 of an inch thick.
All coatings, not just Beral, are susceptible to moisture chemicals
and weathering.
In some environments, over-coatings will last longer.
Beral can be easily removed with Ferric Chloride. Radio Shack sells
this as circuit board etching solution. Just be careful, it will
stain your sink.
Our turn around time is approximately 6 weeks due to heavy volume.
Above 16 inches we have a number of over-coated options. All
over-coatings are deposited by computer controlled e-beam process.
These coatings are billed at our standard commercial rates.
We coat mirrors up to 92 inch diameter and 6000 lbs. Meter class
optics are routine.
For the 1999 calendar year, 1.6% of our revenue was generated from
telescope ( ATM ) mirrors. We are primarily a commercial coater. The
majority of our work is done for research, aerospace and industrial
applications.
I would like to take this opportunity to thank the ATM community for
your patronage over the past seven decades. Although you only come in
at a 1.6 share, you are at the heart and soul of this family business.
My grandfather, Leroy M. E. Clausing, who founded the company in 1927
was an ATM who turned it into a career. (He was also an electrical
engineer who designed and built many of the first radio stations in
the country.) He was a true visionary who helped make the technology
of the future. And as I carry on that tradition, I do not forget the
past..... and where the roots of this company are.
Best Regards,
Howard L. Clausing
H. L. Clausing Inc.
President
P.S Thanks to all of you who sent supportive comments to the group
and also for the private emails.
Jeff
occasionally and word spread then. Hey, that was only a few decades
before Al invented the Internet….. Or maybe you have never seen old
copies of S&T. BTW, I am trying to get rid of my old S&Ts from 1954
throughout 1995.
Jeff
On Thu, 29 Jun 2000 17:46:09 GMT, Del Johnson <deljo...@my-deja.com>
wrote:
>Unitl there was this newsgroup, word did not spread very quickly at
>all. Even then, we are just a few out of the entire marketplace. You
>would be surprised how long a poor product can survive. Take Bushnell
>as an example.
>
>My understanding is that the Beral coating is not SiOx overcoated,
>which has a lot to do with environmental resistance.
>
>Del Johnson
>
>
>
>
>In article <8jfuts$hr1$1...@nnrp1.deja.com>,
> Axel <rites...@hotmail.com> wrote:
>> Jim's point is simply that if everyone had as bad experiences with
>> Clausing that Roland and the other four or five shared had, then
>> Clausing would have gone bankrupt 30 years ago due to a lousy
>> reputation!
>>
>> Tasco survives based on sheer ignorance of the mass public! But
>> Clausing can't do that because people who buy metal coatings are
>> generally very knowledgable and the word spreads quickly in a niche
>> market.
>>
>> My opinion is that these people who had bad experiences were somehow
>> subjecting the mirrors to rare conditions (perhaps unknowingly) that
>> the Clausing coatings were never designed to withstand. Coatings
>> turning brown in less than a year point to a serious problem with the
>> environment in the area (coal-fired power plants?) and maybe
>forgetting
>> to put shower caps on the ends of the tubes!!!?? These cases are
>> definitely in the vast minority, otherwise Clausing would have been
>> laughed out of the coating business years ago.
>>
>> In article <8jftt8$gsj$1...@nnrp1.deja.com>,
>> Del Johnson <deljo...@my-deja.com> wrote:
>> > These seems to be sufficient actual cases detailed in this thread
>for
>> > me to believe Roland. He has no reason to falsify information as he
>> is
>> > not in the coating business. You don't come across as being
>> objective,
>> > Jim, as you simply disregard the numerous user reports.
>> >
>> > Del Johnson
>> >
>> > In article <395A23FC...@my-deja.com>,
>> > JMc <tri...@my-deja.com> wrote:
>> > > Howard,
>> > >
>> > > The largest mirrors AP regularly coats are about 60 mm wide, so
>why
>> > are
>> > > you asking Roland Christen for advice? H. L. Clausing has been
>> coating
>> > > telescope mirrors longer than Roland has been alive. They haven't
>> > > remained in business for 73 years because they don't know what
>> they're
>> > > doing. I'm just amazed at the misinformation and sheer B.S. that
>> gets
>> > > thrown around on saa by people that should know better.
>> > >
>> > > Jim McSheehy
>> > >
>> >
star...@infomagic.net
But I am not really certain that it is the e-beam process Roland was
referring.
Chris1011
Spectrum Coatings uses an ion beam process (IAD, ion assisted deposition).
But I am not really certain that it is the e-beam process Roland was>>
E-beam with ion assist is definitely high tech. The e-beam portion does the
melting of the evaporant, ion assist is used to pack the molecules tightly onto
the glass substrate. This results in a denser, more uniform coating. Normal
evaporation results in a looser structure on the surface of the glass, one that
is prone to moisture absorption. The ion beam is used to "push" the molecules
tightly into the glass. These coatings are tops for longevity and durability.
They are also exceptionally smooth and uniform if done right.
However, just because a company has this equipment is not total assurance that
it will be used for your lone optic. Running one of these high tech production
coaters costs on the order of $800 to $1000 per run. Make sure they actually
put your optic into this particular production stream (these box coaters hold
several mirrors at once so the cost can be divided). If they charge $35 to coat
your 12", well, you're probably getting a cheap coating. Expect to pay $150 to
$200 for a 12". My coater can load four 10" mirrors at once, and the coating
run costs me $850. Some companies have bigger equipment, but this is about
standard right now.
Roland Christen
ASTRO-PHYSICS
jeff...@my-deja.com
figured by, hum forget, to about f/5.
Jeff
In article <20000629122241...@ng-cl1.aol.com>,
whal...@aol.com (WHALEN44) wrote:
> Beast,
>
> Unless they swapped out scopes, the scope in the dome is Dave Raden's
old
> scope that was donated when he passed away a few years back. I believe
the
> coatings are about 15 years old, unless the club had them redone in
the last
> two years.
>
> I will make a few phone calls and report back.
>
> Richard Whalen
> whal...@aol.com
>
> "Time spent observing the heavens is not deducted from your lifespan"
>
star...@infomagic.net
My 18 in. mirror received an IAD from Spectrum at a cost of $180.
That's just a little shy of what you quoted. They specified it as
ion assist, that I am certain. You can check out their web site
just to be sure:
http://www.spectrum-coatings.com/
Thanks,
Ron
Allan Rahill
Rolland...
Can we extrapolate your conclusion for all type of coatings... such as
recoating a regular aluminium surface mirror could be damage?
> >>
> Jim's point is simply that if everyone had as bad experiences with
> Clausing that Roland and the other four or five shared had, then
> Clausing would have gone bankrupt 30 years ago due to a lousy
> reputation!>>
>
> And my point was that these are not fancy coatings like some people claim (read
> my other post about what is a fancy coating). People around here (Chicago area)
> use them because they are cheap, and they acknowledge that they are not the
> best, and that the reflectivity is not high. Our club 12" has been coated and
> recoated numerous times by Clausing, and the surface is now a mess due to the
> number of strippings it has received by Clausing. The mirror was one of the
> finest examples of a paraboloid by Carl Hand, a local ATM who made hundreds of
> mirrors in his lifetime. It used to be an excellent planetary scope, but with
> the surface etched and pitted now, the contrast is very poor. The mirror never
> received a decent coating because there was never a desire to spend any money.
> Now the mirror is beyond repair, and it is serving out it's existence as a
> portable Dobsonian for public star parties and club events.
>
> Roland Christen
> ASTRO-PHYSICS
>
>
~~~~~~
Allan Rahill ___ ( )
/ / ~~/ -- )
/ / (____ CMC )
//@--[]- (_______)
^ /\ ////
/ \ '''
Chris1011
My 18 in. mirror received an IAD from Spectrum at a cost of $180.
That's just a little shy of what you quoted. They specified it as
ion assist, that I am certain. You can check out their web site
just to be sure:
>>
That's a good price. They must have a larger coating machine. My coater is a
bit more expensive. They are getting a larger machine sometime this year, so my
costs may go down.
Roland Christen
ASTRO-PHYSICS
Chris1011
Can we extrapolate your conclusion for all type of coatings... such as
recoating a regular aluminium surface mirror could be damage?
>>
Depends on what kind of acid or base is used to strip off the old coating. Some
powerful stripping agents will attack the glass and etch the surface. It
ususally starts at a hairline scratch, which then opens up and becomes very
ugly after the stripping process. Cleaning a mirror to prepare it for coating
can introduce very fine almost invisible sleeks, which then open up next time
the coating is stripped off.
I prefer to use a very mild acid heavily diluted in water that takes overnight
to work. This is not economically practical for coating shops, and they
normally would use a powerful stripper which can remove coatings in minutes.
Roland Christen
ASTRO-PHYSICS
hcl...@my-deja.com
I have never read so much mis-information in my life.
First of all, rumors of my demise are somewhat premature. I am very much
alive and well, as is my company. It was my uncle who passed away in October
of 1981. You can be sure that the gentleman who said I was dead is equally
as well informed about my coatings.
It is one thing for amateurs to voice opinions in such a format as this. In
fact, I applaud it. Sharing and discussing ideas is vital to science. But I
am especially disappointed with comments made here by Mr. Christen from
ASTRO-PHYSICS. It is extremely unprofessional to slam a competitor in a
public forum. Especially when those comments are totally baseless and
untrue. Be assured my attorney will review them for possible libel.
The facts are as follows:
Beral is indeed an alloy as stated on my web page.
Beral is priced competitively for the amateur market.
Beral is not overcoated so humidity, moisture and acid precipitation may be a
problem in some geographic regions. We recommend Beral on mirrors up to 16
inches. Smaller mirrors tend to be transportable, so they are usually kept
inside and exposed to less weathering.
We make no guarantee on the length of service of any of our coatings. I
don't know of any coater who does. It's hard to guarantee something that is
15/1,000,000 of an inch thick.
All coatings, not just Beral, are susceptible to moisture, chemicals and
weathering.
In some environments, over-coatings will last longer.
Beral can be easily removed with Ferric Chloride. Radio Shack sells this as
circuit board etching solution. Just be careful, it will stain your sink.
Our turn around time is approximately 6 weeks due to heavy volume.
Above 16 inches we have a number of over-coated options. All over-coatings
are deposited by computer controlled e-beam process. These coatings are
billed at our standard commercial rates.
We coat mirrors up to 92 inch diameter and 6000 lbs. Meter class optics are
routine.
For the 1999 calendar year, 1.6% of our revenue was generated from telescope
( ATM ) mirrors. We are primarily a commercial coater. The majority of our
work is done for research, aerospace and industrial applications.
I would like to take this opportunity to thank the ATM community for your
patronage over the past seven decades. Although you only come in at a 1.6
share, you are at the heart and soul of this family business. My
grandfather, Leroy M. E. Clausing, who founded the company in 1927 was an ATM
who turned it into a career. He was also an electrical engineer who designed
and built many of the first radio stations in the country. He was a true
visionary who helped make the technology of the future. And as I carry on
that tradition, I do not forget the past..... and where the roots of this
company are.
Best Regards,
Howard L. Clausing
H. L. Clausing Inc.
President
P.S. Many thanks to those of you with supportive comments to the group and
also for the private emails.
hcl...@my-deja.com
I have never read so much mis-information in my life.
First of all rumors of my demise are absolutely ludicrous. I am very
much alive and well, as is my company. It was my uncle who passed away
in October of 1981. You can be sure that the gentleman who said I was
dead is equally as well informed about my coatings.
It is one thing for amateurs to voice opinions in such a format as this.
In fact, I applaud it. Sharing and discussing ideas is vital to
science. But I am especially disappointed with comments made here by Mr.
Christen from ASTRO-PHYSICS. It is extremely unprofessional to slam
another manufacturer in a public forum. Especially when those comments
are totally baseless and untrue. Be assured my attorney will review
them for possible libel. Mr. Christen has no knowledge whatsoever of
my equipment, corporate structure or capabilities and is totally
unqualified to speak about them.
It rings hollow and bitter when one who does not posses the capability
to coat meter class optics publicly demeans one of the pioneers of the
process. I think people will see this assault for what it really is.
The facts are as follows:
Beral is indeed an alloy as stated on my web page.
Beral is priced competitively for the amateur market. We offer many
other coatings, but due to our overhead, they are often priced beyond
the range of most amateurs. We have made an internal decision to only
offer these other coatings on mirrors over 18" dia.
As a service to ATM's we offer Beral at an almost break even cost.
These chambers are kept in superb condition and are subsidized by our
commercial operation. Beral is an excellent coating. The reason it is
cheap is because we subsidize it.
Beral is an excellent coating for a wide variety of applications,
including telescope mirrors.
Beral is not overcoated so humidity, moisture and acid precipitation may
be a problem in some geographic regions. We recommend Beral on mirrors
up to 16 inches. Smaller mirrors tend to be transportable, so they are
usually kept inside and exposed to less weathering.
We make no guarantee on the length of service of any of our coatings. I
don't know of any coater who does. It's hard to guarantee something
that is 15/1,000,000 of an inch thick.
All coatings, not just Beral, are susceptible to moisture chemicals and
weathering.
In some environments, over-coatings will last longer.
Beral (and most other coatings) can be easily removed with Ferric
Chloride. Radio Shack sells this as circuit board etching solution.
Just be careful, it will stain your sink.
Our turn around time is approximately 6 weeks due to heavy volume.
Above 18 inches we have a number of over-coated options. All
over-coatings are deposited by computer controlled e-beam process.
These coatings are billed at our standard commercial rates.
We coat mirrors up to 92 inch diameter and 6000 lbs. Meter class optics
are routine.
For the 1999 calendar year, 1.6% of our revenue was generated from
telescope ( ATM ) mirrors. We are primarily a commercial coater. The
majority of our work is done for research, aerospace and industrial
applications.
I would like to take this opportunity to thank the ATM community for
your patronage over the past seven decades. Although you only come in
at a 1.6 share, you are at the heart and soul of this family business.
My grandfather, Leroy M. E. Clausing, who founded the company in 1927
was an ATM who turned it into a career. He was also an electrical
engineer who designed and built many of the first radio stations in the
country. He was a true visionary who helped make the technology of the
future. And as I carry on that tradition, I do not forget the past.....
and where the roots of this company are.
Best Regards,
Howard L. Clausing
H. L. Clausing Inc.
President
P.S. Thanks to those who sent supportive comments to the group and also
star...@infomagic.net
having
to send it 2500 mi. across the country. The mirror came back in pristine shape.
Every mirror I get from now on is going there to get coated.
Jeff
you ruined my 12.5-inch f/4 mirror sometime in the early 1980's after
your uncle, P.A., passed on. Many of us knew him and his service was
great. The initials were an over sight; I would have changed it to
P.A. if it were possible. No apologies here, I simply make a simple
mistake.
BTW, when P.A. ran the business he cleaned the mirrors so they would
not pit from beneath the coat. Also, if he had ruined my mirror by
goring the glass he would have never hung up on me when I called to
complain, as you did! Your coatings have not lasted more than a few
weeks on many of my friend's mirrors after your service and you can
either take this as constructive criticism or lump it. I, and
probably those many friends, will never recommend your service again.
Jeff
On Sat, 01 Jul 2000 15:32:22 GMT, hcl...@my-deja.com wrote:
>Gentlemen,
>
>I have never read so much mis-information in my life.
>
>First of all, rumors of my demise are somewhat premature. I am very much
>alive and well, as is my company. It was my uncle who passed away in October
>of 1981. You can be sure that the gentleman who said I was dead is equally
>as well informed about my coatings.
>
>It is one thing for amateurs to voice opinions in such a format as this. In
>fact, I applaud it. Sharing and discussing ideas is vital to science. But I
>am especially disappointed with comments made here by Mr. Christen from
>ASTRO-PHYSICS. It is extremely unprofessional to slam a competitor in a
>public forum. Especially when those comments are totally baseless and
>untrue. Be assured my attorney will review them for possible libel.
>
>The facts are as follows:
>
>Beral is indeed an alloy as stated on my web page.
>
>Beral is priced competitively for the amateur market.
>
>Beral is not overcoated so humidity, moisture and acid precipitation may be a
>problem in some geographic regions. We recommend Beral on mirrors up to 16
>inches. Smaller mirrors tend to be transportable, so they are usually kept
>inside and exposed to less weathering.
>
>We make no guarantee on the length of service of any of our coatings. I
>don't know of any coater who does. It's hard to guarantee something that is
>15/1,000,000 of an inch thick.
>
>All coatings, not just Beral, are susceptible to moisture, chemicals and
>weathering.
>
>In some environments, over-coatings will last longer.
>
>Beral can be easily removed with Ferric Chloride. Radio Shack sells this as
>circuit board etching solution. Just be careful, it will stain your sink.
>
>Our turn around time is approximately 6 weeks due to heavy volume.
>
>Above 16 inches we have a number of over-coated options. All over-coatings
>are deposited by computer controlled e-beam process. These coatings are
>billed at our standard commercial rates.
>
>We coat mirrors up to 92 inch diameter and 6000 lbs. Meter class optics are
>routine.
>
>For the 1999 calendar year, 1.6% of our revenue was generated from telescope
>( ATM ) mirrors. We are primarily a commercial coater. The majority of our
>work is done for research, aerospace and industrial applications.
>
>I would like to take this opportunity to thank the ATM community for your
>patronage over the past seven decades. Although you only come in at a 1.6
>share, you are at the heart and soul of this family business. My
>grandfather, Leroy M. E. Clausing, who founded the company in 1927 was an ATM
>who turned it into a career. He was also an electrical engineer who designed
>and built many of the first radio stations in the country. He was a true
>visionary who helped make the technology of the future. And as I carry on
>that tradition, I do not forget the past..... and where the roots of this
>company are.
>
>
>Best Regards,
>
>Howard L. Clausing
>H. L. Clausing Inc.
>President
>
>
>P.S. Many thanks to those of you with supportive comments to the group and
Blandp1
Hash: SHA1
>It is extremely unprofessional to slam a competitor in a
>public forum.
I didn't know Astro-Physics coated mirrors! I wonder how much
they charge... :-)
- -Philip J. Blanda III
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Valentine Germann
I am getting ready to send you a 12.5-inch
mirror that I have already removed the coating
from with sodium hydroxide. Will this make
any difference to you folks in handling the mirror?
That is, it would have been better if I had just left
it alone, wouldn't it?
Also, is there a chance of chemical damage to
the glass substrate when the old coating is removed?
Val Germann
Central Missouri Astronomical Association
Columbia, Missouri
Martin Brown
Valentine Germann wrote:
> I am getting ready to send you a 12.5-inch
> mirror that I have already removed the coating
> from with sodium hydroxide. Will this make
> any difference to you folks in handling the mirror?
> That is, it would have been better if I had just left
> it alone, wouldn't it?
Strong caustic is not a good choice for removing aluminium from optics
as it can also dissolve glass - especially near scratches or stress
lines. Chances are that very little damage will have been done unless
you used a strong solution and left it in overnight.
> Also, is there a chance of chemical damage to
> the glass substrate when the old coating is removed?
Possibly. Strong alkalis like sodium (or potassium) hydroxide or even
worse hydrofluoric acid are the chemicals most likely to attack glass.
It depends how strong the solution you used was and how long you left it
in contact. And how well you rinsed it afterwards.
Regards,
Martin Brown
Vahe Sahakian
> It is one thing for amateurs to voice opinions in such a format as
> this. In fact, I applaud it. Sharing and discussing ideas is vital
> to science. But I am especially disappointed with comments made here
> by Mr. Christen from ASTRO-PHYSICS. It is extremely unprofessional to
> slam a competitor in a public forum. Especially when those comments
> are totally baseless and untrue. Be assured my attorney will review
> them for possible libel.
My scope has beral coatings, had it for about a year, no problems so
far.
All mirror coatings, the simple ones or enhanced, can be problematic, it
is the nature of the beast and is dependent on too many variables, this
public forum is one of the few places where we can hear opinions from
amateurs regarding the quality of various products and services
available to us.
Now, you are correct when you refer to tons of misinformation that is
available free of charge on this newsgroup, but that is also the nature
of the beast, we all recognize that but would like to maintain the free
flow of information and be able to discuss all issues and draw our own
conclusions.
Just like your grandfather, Roland started as an ATM and I am thankful
that he still contributes to this newsgroup, I do not always agree with
his opinions, but I feel that he, just like the rest of us is entitled
to his own brand of opinions even if they are baseless and untrue.
As for his "unprofessional" conduct to slam a competitor in a public
forum, as I see it you two are really not competitors, you are not
producing refractors or mounts and he is not offering coating services
to the public.
Thanks,
Vahe
Valentine Germann
Thanks for your message. I didn't leave the
Sodium Hydroxide on the glass long. That is,
it took off the aluminum pretty quickly, all except
for for a few tiny flecks which I pretty much left
alone. Then I did have the sense to rinse the
mirror with distilled water before packing it up.
I probably had the chemical on the surface for
no more than 10-15 minutes total time.
Thanks again!
Val
P.S. However, I have used, er, nitric acid to
clean a mirror, in hopes of getting it "chemically
clean" for a silver coating! That material was
not on there long, either, let me tell you. . .it was
a matter of 30 seconds or so! I think some of
the old amateur sources recommend "smoking
nitric acid" or some such. Look out!
**
WHALEN44
Well said - ditto (except 7 months)
So what did you buy your TEC for it's first birthday? Mine wants a AP4 :-)
Vahe Sahakian
Birthday present: an AP900, waiting for gas giants.
PS what is AP4?
Thanks,
Vahe
Chris1011
public forum. >>
I am not your competitor.
Roland Christen
ASTRO-PHYSICS
Chris1011
First of all, rumors of my demise are somewhat premature. I am very much
alive and well, as is my company. It was my uncle who passed away in October
of 1981. You can be sure that the gentleman who said I was dead is equally
as well informed about my coatings.
>>
By the way, please inform your Lawyer that it was not me who said you were
dead.
And P.S. you ruined our club 12" with your stripping process, as well as one of
my friend's 16".
Roland Christen
ASTRO-PHYSICS
Bob May
acid chemicals used for stripping a coating off but that assumes that
the stripping was done correctly and that the mirror was incompletely
polished out properly. Short polishing times don't fully remove all
of the problems and will allow for the acid to poke holes in the
surface and thus cause a problem. It's not to say that a longer
stripping time than necessary didn't assist in the cause of the
problem but I always quake when a mirror needs to be stripped as you
never know if the mirror got polished out fully so that there are no
weak spots in the surface where the acid can do it's work.
--
Bob May
Access1 has gone Chapter 7 so I don't know how long my website is
going to last.
Bob May