Velvet - What Glue/Adhesive to Use?
Sue and Alan
has done this have any suggestions for what type of glue to use?
Clear skies, Alan
RichardN22
I've decided to line my revived 8" f/8's tube with velvet. Does anyone who
has done this have any suggestions for what type of glue to use?
Clear skies, Alan>>
I used spray adhesive for some felt I placed opposite the focuser on my 6" f8.
So far so good and easy to use. You get an even coating with a spray.
Richard
Richard Navarrete
Richa...@aol.com
Astrophotography Web Page - http://members.aol.com/richardn22
Chuck Gulker
backing. Works great.
Chuck
bratislav wrote in message <36E6F72B...@down.under.au>...
>Sue and Alan wrote:
>>
>> I've decided to line my revived 8" f/8's tube with velvet. Does anyone
who
>> has done this have any suggestions for what type of glue to use?
>>
>> Clear skies, Alan
>
>Alan,
>
>I first tried superglue and although it did hold, it was extremely messy
(it
>is so liquid that soaks throuogh the velvet if you press it in place).
Contact
>cement is much better for handling but you will need to grow couple more
>hands for that operation :-)
>I would seriously consider lining the tube with self adhesive 'velvet'
>(from hardware stores - surprisingly good at grazing angles!) and only
cover
>a critical patch behind the secondary with a quality velvet (which is
>quite expensive !). Don't forget to line the velvet inside focuser and
>adapter/extension tubes.
>
>Bratislav
William Sommerwerck
let you reposition the material.
Preston Justis
I would be wary of lining the whole tube with velvet, especially
the adhesive backed stuff. I read about a fellow using adhesive
backed velvet or felt (?) opposite of the focuser. The adhesive
released after a short period of time and fell onto the primary
mirror :-O. I'd also be worried about lots of fibers floating around
inside the tube as the velvet aged. Of course, if you regularly
clean the optics this won't be a problem.
As far as applying the velvet, there are some good
spray-on contact adhesives made by 3M that can be found at your
local paint supplier. I have used a paint made by Krylon called
'ultra-flat black'. It's pretty easy to apply as it comes in spray cans
and is really _flat black_. This is a good alternative in case you
change your mind and decide against using velvet.
Clear skies to you !
Scott
P.S.- I'm looking forward to Susan's next deep sky article in S+T :).
Sue and Alan wrote in message <7c6mjo$h...@news1.newsguy.com>...
Rich N.
hold without letting go in a few months. It certainly
works well with glass and metal.
Rich
Mike_Stebbins
quit a difference and has held for two years now, including nights with
heavy dew. Just remember to take out the optics and not replace them until
the adhesive has totally dried and stopped outgassing.
Mike Stebbins
Warren Porter
I was going to be a smart a-- and ask what color, red or green but will fore go
that bit. 3M Super 77 is a spray adhesive that holds like a leech. The
problem may be that you won't be able to get any wrinkles out. It has almost
no work time, what hits it sticks. I use it for mounting various art work but
would hesitate to try to line a tube using it.
Warren
bratislav
>
> I've decided to line my revived 8" f/8's tube with velvet. Does anyone who
> has done this have any suggestions for what type of glue to use?
>
> Clear skies, Alan
Alan,
Dennis Simmons
who
> has done this have any suggestions for what type of glue to use?
>
> Clear skies, Alan
>
Be careful with contact adhesives - they continue to outgas for some time
after their application and attack certain substances.
I recently built a small wooden box to house a guidescope, and lined it
with velvet which I attached using contact adhesive. The next day I added
the polystyrene cut-outs that came with the guidescope to support the
guidescope in the box. They were a push fit and not glued in as I know that
contact adhesive "melts" polystyrene.
Two days later I opened the box and found that the polystyrene cut-outs had
partially "melted" due to the glue outgassing.
The velvet maintains its softness provided you do not saturate it with
glue, which would then make it rigid. The flocks of cloth may then act as
an abrasive rather than a soft buffer.
Regards
Dennis Simmons
Reid Williams
Rich N. wrote in message <7c73tb$m37$1...@remarQ.com>...
Exactly.
I used double-sided carpet tape to attach my blackening material to the
entire tube.
Be sure to double check the tape. There is double sided masking tape (not
very good) available as well as the professional 2" carpet tape. (Home Depot
~$5 for a 15 yard roll)
Reid Williams.
Stephen Tonkin
>I've decided to line my revived 8" f/8's tube with velvet. Does anyone who
>has done this have any suggestions for what type of glue to use?
Copydex (latex adhesive) is good for most fabrics and does not outgas
significantly for more than an hour or so.
3M do some spray adhesives; Photomount works well, but it does outgas
for quite a long time (days).
Noctis Gaudia Carpe,
Stephen
--
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To send email, substitute "aegis1" for "nospam"
Sue and Alan
and Stephen for your advice.
I'm going to go with the carpet tape as it sound more easily managed.
There was a gentleman at Stelli this past year that had a tube with sections
lined with different material. At grazing angles the velvet was obviously
much darker than flocked paper. I bought the velvet quite a few years ago,
so price is not an issue.
Thanks again.
Clear skies, Alan
Sue and Alan wrote in message <7c6mjo$h...@news1.newsguy.com>...
Berto Monard
I don't know what you mean with velvet, a fabric or paper?
I have covered the inside of my telescope tube with velvet paper. I used what
we call here 'Pritt' to glue it on. It works easily and it still sticks after
several months.
I don't know what you have available there but a visit to a Primary School will
definitely show the kind of stuff those children use to stick there pieces of
paper cuttings....
Berto Monard
Pretoria
///
Sue and Alan wrote:
> I've decided to line my revived 8" f/8's tube with velvet. Does anyone who
> has done this have any suggestions for what type of glue to use?
>
> Clear skies, Alan
Rich N.
but have yet to install it in my telescope.
I have been thinking of using self adhesive Velcro strips on
the inside of the upper assembly of my truss tube Dobs and
sewing Velcro strips or patches on the back side of the Velcro.
Or maybe gluing the Velcro to the back of the velvet?
But then why use Velcro if there is really no need to be removing
the velvet? ;-)
Rich
Berto Monard wrote in message <36E7A46D...@csir.co.za>...
PaulHBock
inside tubes. That is also what D&G Optical uses on their excellent
refractors. When dry, it looks like lampblack (i.e., soot), which is about as
flat as you can possibly get. No reflections.
If you really wish to line the entire inside of the tube with a
light-absorbing material, I recommend self-adhesive black light-absorbing paper
specifically designed for optical use. It is available from Edmund Scientific:
p/n A70,621 20" x 30" sheet, $8.00
p/n A70,622 Pkg of 50 sheets, $165.00
I have used this paper to line the inside of a metal dew cap on a
refractor to help reduce heat loss from the lens cell and delay the onset of
dewing, and it does help. Of course, a non-metallic dew cap is a better
solution.....
The paper is also available without the adhesive backing:
p/n A60,068 27" x 36" pkg of two sheets, $7.75
Paul Bock
Hamilton, VA
Chuck Gulker
The above is the Protostar link to their flocking paper. I used some last
night to flock the last inch of my focus tube. Sure helps. Chuck
PaulHBock wrote in message <19990313091919...@ng-fb1.aol.com>...
Jeff Morgan
paul...@aol.com (PaulHBock) wrote:
> I've had excellent results using Krylon "Ultra Flat Black" spray paint
> inside tubes. That is also what D&G Optical uses on their excellent
> refractors. When dry, it looks like lampblack (i.e., soot), which is about as
> flat as you can possibly get. No reflections.
Paul,
Krylon UFB is ok, but not nearly as black as you think.
I used Krylon UFB combined with fine sand (for texture) to blacken my last
Newtonian. Some time later I purchased black flocking paper from ProtoStar
Systems, and placed a strip inside the tube over the Krylon UFB. When I
looked down the tube, the contrast between the two was stunning: the
flocking paper made the Krylon UFB look absolutely GRAY.
--
Jeff Morgan
email: substitute mindspring for nospam
Sue and Alan
I have used Krylon "Ultra Flat Black" and the Edmund flocked paper. At
grazing angles neither strike me as being all that black - especially when
compared to velvet cloth.
Clear skies, Alan
PaulHBock wrote in message <19990313091919...@ng-fb1.aol.com>...
> I've had excellent results using Krylon "Ultra Flat Black" spray paint
>inside tubes. That is also what D&G Optical uses on their excellent
>refractors. When dry, it looks like lampblack (i.e., soot), which is about
as
>flat as you can possibly get. No reflections.
>
> If you really wish to line the entire inside of the tube with a
>light-absorbing material, I recommend self-adhesive black light-absorbing
paper
>specifically designed for optical use. It is available from Edmund
Scientific:
>[SNIP]
PaulHBock
>I have used Krylon "Ultra Flat Black" and the Edmund flocked paper. At
>grazing angles neither strike me as being all that black - especially when
>compared to velvet cloth.
I can't argue with your observation, you may well be absolutely correct.
The question uppermost in my mind is what difference it makes in a small (8"
or less) telescope. Will I see some noticeable difference? In what size
aperture? Is there any scientifically documented evidence of this in
side-by-side comparisons? Any scattered light, however miniscule, should be
easily measurable using the instrumentation available today; has anyone
actually done this, and if so what are the numbers? And most of all, will any
difference be worth the aggravation of trying to glue velvet cloth along the
full length of an OTA?
Not trying to be ornary here, just wondering why someone would go to all
that trouble when manufacturers of truly precision optics, like D&G, A-P,
Questar, etc., don't bother to do it.
Paul Bock
* Paul H. Bock, Jr.
* * Hamilton, VA U.S.A.
* * * * RASC, A.L.P.O., WHS
* G *
* * * *
* * *
Sue and Alan
Well, I view it as an interesting problem and a challenge, not an
aggravation. If it does really turn out to be an aggravation, then I will
change my approach.
There is a big difference between Newts and refractors - you can easily
place knife edge baffles in a refractor tube to nicely handle stray light.
A Newtonian does not have a converging light cone, so baffles are not as
satisfactory there. My next project is a new tube for our 8" refractor and
I am going to mainly rely on baffles and be somewhat less concerned with
what black material I have in the tube.
Does it really make a difference? We'll see our the completed scopes
compare to other eights. Maybe we will see a difference. Maybe we won't.
But part of the fun of building scopes is trying different things.
Clear skies, Alan
PaulHBock wrote in message <19990313231035...@ng-cf1.aol.com>...
>[SNIP] And most of all, will any
Zane
>Paul,
>
>I have used Krylon "Ultra Flat Black" and the Edmund flocked paper. At
>grazing angles neither strike me as being all that black - especially when
>compared to velvet cloth.
(snip)
Think about using some highly reflective, low scatter metal foil in some
key places to redirect the light instead of trying to absorb it. Sometimes
a mix with flat black surfaces in other places is good.
Zane
PaulHBock
>Well, I view it as an interesting problem and a challenge, not an aggravation.
If it does really turn out to be an aggravation, then I will change my
approach.
>Does it really make a difference? We'll see our the completed scopes compare
to other eights. Maybe we will see a difference. Maybe we won't. But part of
the fun of building scopes is trying different things.
Very well said indeed, Alan, and I cannot argue with it. One person's
aggravation is another's challenge, and I'm as guilty as anyone of doing things
that others considered "aggravations" - although admittedly not in the area of
light entrapment/absorption.
Your expertise in Newtonians certainly exceeds mine (which is essentially
zero) and I hadn't thought about the problem that the light cone isn't
converging. An excellent point.
Perhaps when you have carried your experiments a bit farther, might we see
some kind of published report with comparisons between different coatings &
materials, as well as a "sidebar" on which adhesives seem best with various
materials? This seems to me to be an area that has been generally neglected or
at least taken for granted (I certainly have done so based on what I've read so
far on this thread) , so perhaps the technological aspects of stray light
control in Newtonians and such is worthy of serious reevaluation and research.
Clear skies to you,
Paul (in snowy northern Virginia)
RichardN22
>
>I have used Krylon "Ultra Flat Black" and the Edmund flocked paper. At
>grazing angles neither strike me as being all that black - especially when
>compared to velvet cloth.
>>
Has anyone tried using wide strips of the fuzzy side of velcro across from a
focuser? Is it too fuzzy? The stuff seems very black and I would think all
the fuzz would act like tiny baffles. It's even self-adhesive.
Mike Dumas
Jeff Morgan wrote:
> Krylon UFB is ok, but not nearly as black as you think.
>
> I used Krylon UFB combined with fine sand (for texture) to blacken my last
> Newtonian. Some time later I purchased black flocking paper from ProtoStar
> Systems, and placed a strip inside the tube over the Krylon UFB. When I
> looked down the tube, the contrast between the two was stunning: the
> flocking paper made the Krylon UFB look absolutely GRAY.
http://cyber.wmis.net/~rv6/Texture_tube.html
Is about using crushed walnuts and Krylon UFB...
He was amazed with his results.
Maybe the coarser texture does better than your Sand Texture did?
mike
Jeff Morgan
> http://cyber.wmis.net/~rv6/Texture_tube.html
>
> Is about using crushed walnuts and Krylon UFB...
>
> He was amazed with his results.
>
> Maybe the coarser texture does better than your Sand Texture did?
>
>
> mike
Mike,
My first Newtonian used sawdust from a table saw, painted with Krylon UFB.
Then I saw that the "micro texture" of sand gave me more "baffles". I
should say that each time (sawdust, then sand) I was amazed at how well it
worked. However, by seeing what other people were doing, I got a little
smarter each time.
Now, I have found that flocking paper is better than overcoated sand or
sawdust. And easier to apply. The last issue of Amatuer Astronomy had a
comparison where black velvet was better than flocking paper. So, it would
seem I have learned something new. Would crushed walnuts be better? Guess
I have to try it.
Mike Dumas
Jeff Morgan wrote:
> Mike,
>
> My first Newtonian used sawdust from a table saw, painted with Krylon UFB.
> Then I saw that the "micro texture" of sand gave me more "baffles". I
> should say that each time (sawdust, then sand) I was amazed at how well it
> worked. However, by seeing what other people were doing, I got a little
> smarter each time.
>
> Now, I have found that flocking paper is better than overcoated sand or
> sawdust. And easier to apply. The last issue of Amatuer Astronomy had a
> comparison where black velvet was better than flocking paper. So, it would
> seem I have learned something new. Would crushed walnuts be better? Guess
> I have to try it.
Hi Jeff,
I'm building my first scope, a 8" f5 and am curious to what will work the
best.
The Crushed Walnuts are Very Coarse compared to Sand or SawDust
as evidenced in the photos on his web site. He noticed a impressive
improvement
in performance over the untreated Bakelite of his 6" Dynascope...
This doesn't mean Flocking Paper or Velvet won't out perform them.
Something else to consider is the performance on different diameters and
length
of tubes with different textures. Varying results could show up.
But one thing is definite, any darkening treatment will be better than none.
mike
Perry
<19990313231035...@ng-cf1.aol.com>...
> Alan said:
>
> >I have used Krylon "Ultra Flat Black" and the Edmund flocked paper. At
> >grazing angles neither strike me as being all that black - especially
when
> >compared to velvet cloth.
>
> Not trying to be ornary here, just wondering why someone would go to
all
> that trouble when manufacturers of truly precision optics, like D&G, A-P,
> Questar, etc., don't bother to do it.
>
Paul
And what do D&G, A-P, Questar, etc. use to reduce stray light?
--
Bob Perry ~ 40 N 90 W, on my son's computer and my wife's account,
with < b i t b u c k e t . > faked into my address for the .S.P.A.M.bots,
just don't use it yourself.
Rich N.
Perry wrote in message <01be6ef8$36c6de20$872564ce@perrycn>...
-snip
>>
>> >I have used Krylon "Ultra Flat Black" and the Edmund flocked paper. At
>> >grazing angles neither strike me as being all that black - especially
>when
>> >compared to velvet cloth.
>>
>all
>> that trouble when manufacturers of truly precision optics, like D&G, A-P,
>> Questar, etc., don't bother to do it.
>>
>> Paul Bock
>
>Paul
>
>And what do D&G, A-P, Questar, etc. use to reduce stray light?
A-P places a number of baffles in the tube and focuser assembly
and they use some form of flat black "paint".
Rich
Jeff Morgan
>
> Hi Jeff,
>
> I'm building my first scope, a 8" f5 and am curious to what will work the
> best.
>
> The Crushed Walnuts are Very Coarse compared to Sand or SawDust
> as evidenced in the photos on his web site. He noticed a impressive
> improvement
> in performance over the untreated Bakelite of his 6" Dynascope...
>
> This doesn't mean Flocking Paper or Velvet won't out perform them.
>
> Something else to consider is the performance on different diameters and
> length
> of tubes with different textures. Varying results could show up.
>
> But one thing is definite, any darkening treatment will be better than none.
>
>
> mike
Mike,
Yes, any treatment will be better than none. In absolute terms, none of
them is very expensive (compared to say, eyepieces). For a 10" diameter
tube, the fabric should be easy to apply. (I did a 4" refractor, wouldn't
want to do a smaller tube.) Your scope is relatively short too, so no
problems there.
Good Luck.
Jeff Morgan
<per...@bitbucket.apci.net> wrote:
> Paul
>
> And what do D&G, A-P, Questar, etc. use to reduce stray light?
Maybe D&G, A-P, Questar, etc. could be even better.
Perry
Rich N. <rn...@znet.com> wrote in article <7cjq20$ft2$1...@remarQ.com>...
>
> Perry wrote in message <01be6ef8$36c6de20$872564ce@perrycn>...
> -snip
> >And what do D&G, A-P, Questar, etc. use to reduce stray light?
>
>
> A-P places a number of baffles in the tube and focuser assembly
> and they use some form of flat black "paint".
>
> Rich
>
OK
Rich N.
Jeff Morgan wrote in message ...
>In article <01be6ef8$36c6de20$872564ce@perrycn>, "Perry"
><per...@bitbucket.apci.net> wrote:
>
>
>> Paul
>>
>
>
>
Maybe, but have you looked into or through an Astro-Physics refractor?
Take a look down the objective of one of the new 155EDFs. Lots of
baffles. Then look into the focuser, more baffles.
Rich
mpi...@webmail.bellsouth.net
No problem after several months and it won't be impossible to remove should I
wish to do so.
Regards,
Mark Pippin
Small Dob Web Site
http://personal.lig.bellsouth.net/~gpippin
In article <7c6mjo$h...@news1.newsguy.com>,
"Sue and Alan" <sue_and_a...@msn.com> wrote:
> I've decided to line my revived 8" f/8's tube with velvet. Does anyone who
> has done this have any suggestions for what type of glue to use?
>
> Clear skies, Alan
>
>
-----------== Posted via Deja News, The Discussion Network ==----------
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PaulHBock
Both of my A-P 4" refractors and my D&G 5" refractor used successively
smaller baffles and flat black paint; I know D&G used Krylon Ultra Flat Black
(I asked Barry about it) and A-P used something similar, but I wouldn't swear
to the brand name or exact paint type. Of course, a refractor has a steadily
converging light cone, which makes the job of baffling much easier.
I have no idea what Questar coated the inside of my '98 Q3.5 with, but I
can call Jim Reichart and ask him if someone is interested in knowing exactly
what is used. They do use some type of special baffling on the sliding tube.
Just to make sure there is no misunderstanding, when I said "go to all
that trouble" I meant the trouble of gluing black velvet inside of the tube
assembly as opposed to simply painting it.
But as Alan pointed out, a Newtonian is a different breed as it doesn't
have that nice, converging light cone like a refractor.
Paul Bock
Michael Spooner
>
> Not trying to be ornary here, just wondering why someone would go to all
> that trouble when manufacturers of truly precision optics, like D&G, A-P,
> Questar, etc., don't bother to do it.
>
> Paul Bock
> * Paul H. Bock, Jr.
> * * Hamilton, VA U.S.A.
> * * * * RASC, A.L.P.O., WHS
> * G *
> * * * *
> * * *
I use Krylon UFB for the 8" and 10" Newtonian OTAs I've been making
along with slightly longer tubes. I prefer to spend the time on the
optics and let the user determine if flocking paper is a worthwhile
upgrade. If I should happen to see better images, I'll definitely
investigate.
--Mike
bratislav
> I use Krylon UFB for the 8" and 10" Newtonian OTAs I've been making
> along with slightly longer tubes. I prefer to spend the time on the
> optics and let the user determine if flocking paper is a worthwhile
> upgrade. If I should happen to see better images, I'll definitely
> investigate.
Mike, try the velvet patch behind the diagonal. If nothing else,
pure blackness will PSYCHOLOGICALLY make you see the difference :-)
Good velevet is _amazingly_ black. Just place any other common 'black'
on top of it (even flocking paper) and it will suddenly become gray.
Krylon will be painfully bright, trust me !
Bratislav
Perry
PaulHBock <paul...@aol.com> wrote in article
<19990315220453...@ng-fx1.aol.com>...
>
> . . .
>
> Just to make sure there is no misunderstanding, when I said "go to
all
> that trouble" I meant the trouble of gluing black velvet inside of the
tube
> assembly as opposed to simply painting it.
>
> But as Alan pointed out, a Newtonian is a different breed as it
doesn't
> have that nice, converging light cone like a refractor.
>
> Paul Bock
>
Well, there is a light cone in a Newtonian of course, it's just that it
opens out from the primary so baffling isn't as simple. There is a good
discussion of to baffle or not to baffle links from
http://www.atmpage.com/optic.html