Annealing question
David Babb
I have been making beads now for a few months and am starting to
have some that I would like to stay around for a while. My
question is this... I do not yet have a kiln but was wondering
if I could take a bunch of beads to a studio (ceramic or otherwise)
and rent some kiln time. It would seem to me that any kiln with a
controller could get the annealing temperature and cool down ramp
correct. Also, if I have already taken the beads off the mandrels
(but NOT cleaned out the bead release from the inside of the bead)
can I just stick the bead back on the mandrel to be annealed? (or
do you think that it will stick?) Any comments about what I can
do until I can afford a kiln would be helpful.
Specific question:
I am using Moretti glass (annealing range of 920-968 F). Can anyone
suggest the ramp-up, soak, and cool down times? (etc. 1hr, 20 min,
4 hrs?)
Thank you all for your time.
David
Bobfuses
>controller could get the annealing temperature and cool down ramp
>correct. Also, if I have already taken the beads off the mandrels
>(but NOT cleaned out the bead release from the inside of the bead)
>can I just stick the bead back on the mandrel to be annealed?
You do not need to have the bead on the mandrel to anneal it. At annealing
temperatures the bead can just sit on the shelf and it will not be marked.
The annealing time and cooling cycle depends on the size of the bead mostly. A
program of two hours to get up to anneal, one hour at anneal and three hours to
cool should serve well for most cases.
Many ceramic places cone fire only in large kilns and do not have automatic
controllers. You might have better luck at a stained glass studio that does
fusing.
Bob in 92026
Sundog
on 'high' and filled with vermiculite to hold & then cool beads up to
3/4"......... and almost all survive long term. I could easily really
anneal them in a kiln, but it hasn't been much of an issue yet. NOTE > This
is NOT annealing actually, as any stress removal is performed using the
torch prior to placing the bead into the vermiculite. This performs more
the function of avoiding 'thermal shock' by too rapid irregular cooling. I
do recommend insulation beneath a skillet used in this manner. For beads
only, this works for me.
Yes.......I do pay much more attention to annealing large pieces of fused
glass.
regards, Jacques Bordeleau
CptArrghh wrote in message <20000306225817...@ng-fe1.aol.com>...
>I'm NOT a Lampworker...but I thought beadwork could be annealed by
smothering
>it in a box of Vermiculite.... No???
Terry L. Thatcher
temperature -- that is, when firing porcelain (at least -- that's what my mom does
so I'm more familiar with this aspect) the cone melts or deforms at a certain
temperature and trips the switch, so the kiln reaches that temperature and does not
pass it. But for annealing you want your glass to soak at a certain temperature for
a certain amount of time. Ceramic kilns might not work for that reason (unless they
have a controller attached instead).
You might consider buying yourself a small, portable type kiln for annealing beads
-- there are some on the market which aren't too expensive, although if you add the
cost of an electronic controller the price shoots up. I did spring for the
controller when I got my kiln and I'm glad that I did, because it makes things much
more convenient. I think that in the long run it has paid for itself in eliminating
mental anguish, but of course you have to consider your budget. (Notice I didn't
say it had paid for itself in terms of selling beads...;-p -- maybe that will come
later, someday!)
Bobfuses wrote:
--
--------------------
Terry L. Thatcher 蔡琳
Translation and Conference Interpretation
Chinese, Spanish and English
www.fanyi.com
fax: (703) 935-2591 or (886-2) 2720-4941
CptArrghh
Terry Harper
>Another possible problem is that some ceramic kilns use cones to control
>temperature -- that is, when firing porcelain (at least -- that's what my
mom does
>so I'm more familiar with this aspect) the cone melts or deforms at a
certain
>temperature and trips the switch, so the kiln reaches that temperature and
does not
>pass it. But for annealing you want your glass to soak at a certain
temperature for
>a certain amount of time. Ceramic kilns might not work for that reason
(unless they
>have a controller attached instead).
>
There is a little fallacy here. Annealing is time and temperature dependent.
If you go to a high enough temperature, the dwell time is only a few
seconds. Hence the cone methods would work if you have the temperature
right. If you go too high, then you will get some deformation/slumping.
If the glass is hot when it goes in, then it will probably average itself
out before it starts to cool down.
Like someone said, if you put just-formed glass in a bucket of sand, cover
it and leave till it's cooled down, you have probably annealed it
adequately.
--
Terry Harper, Web Co-ordinator, The Omnibus Society
http://www.omnibussoc.org
E-mail: terry....@btinternet.com
URL: http://www.terry.harper.btinternet.co.uk/
LBMyers
There is a good discussion on bead annealing and cooling on www.cdvkiln.com
GlassOrchid <tna...@optonline.net> wrote in message
news:Yvix4.10$na4...@news.optonline.net...
> Bob (or anyone):
>
> How long does it take for cracks to appear in non-kiln-annealed beads?
I've
> been making beads since last summer and haven't had any that did crack*
but
> mine are pretty simple and not real large. I appreciate the advice; I
> taught myself lampwork from a book.... sort of leaves one wanting.....
Nancy Block
>Hello all,
>
>I have been making beads now for a few months and am starting to
>have some that I would like to stay around for a while. My
>question is this... I do not yet have a kiln but was wondering
>if I could take a bunch of beads to a studio (ceramic or otherwise)
You've got to get them into the kiln right after you've made
them. Without a kiln, bury them immediately in vermiculite or put
them (all this still on mandrels) between two layers of fiber blanket.
Overnight.
Nancy
GlassOrchid
using an annealing kiln?
Nancy
"Nancy Block" <na...@dryad.ebay.sun.com> wrote in message
news:8a48bb$8dh$3...@ebaynews1.EBay.Sun.COM...
Bobfuses
>using an annealing kiln?
>
>Nancy
Perhaps the best answer is when you want a professional product that is worthy
of being sold to the public.
With small beads you can get away with just about anything. The larger the bead
the more critical it is to remove strain by annealing and slow cooling
thereafter to avoid thermal shock.
Bob in 92026
GlassOrchid
How long does it take for cracks to appear in non-kiln-annealed beads? I've
been making beads since last summer and haven't had any that did crack* but
mine are pretty simple and not real large. I appreciate the advice; I
taught myself lampwork from a book.... sort of leaves one wanting.....
I just got a video on lampwork and the maker showed flame annealing (I think
that's what it was called) where she turned up the propane and the bead got
covered in black soot. Then she turned the oxygen back up and the black
burned off. I really didn't understand the point of that... ?? Do you do
that? If so, why?
Nancy
*some did crack but in the first 24 hours.... I'm talking about after that.
"Bobfuses" <bobf...@aol.com> wrote in message
news:20000307204203...@ng-cv1.aol.com...
Nancy Block
>Are fiber blankets enough? What determines when you really have to start
>using an annealing kiln?
I think size and value of beads. I only made beads for a year or two,
but generally had no cracking problems using fiber blanket. Before you put
the bead between the layers, pass it through the end of the flame a few times
letting it cool off between passes to just the point where it stops glowing.
Nancy
>
>"Nancy Block" <na...@dryad.ebay.sun.com> wrote in message
>news:8a48bb$8dh$3...@ebaynews1.EBay.Sun.COM...
>> In article 7577...@essc.psu.edu, David Babb <db...@essc.psu.edu> writes:
>> >Hello all,
>> >
>> >I have been making beads now for a few months and am starting to
>> >have some that I would like to stay around for a while. My
>> >question is this... I do not yet have a kiln but was wondering
>> >if I could take a bunch of beads to a studio (ceramic or otherwise)
>> >and rent some kiln time.
>>
>> You've got to get them into the kiln right after you've made
>> them. Without a kiln, bury them immediately in vermiculite or put
>> them (all this still on mandrels) between two layers of fiber blanket.
>> Overnight.
>>
>> Nancy
>>
>
>
---
Terry Harper
>
>I just got a video on lampwork and the maker showed flame annealing (I
think
>that's what it was called) where she turned up the propane and the bead got
>covered in black soot. Then she turned the oxygen back up and the black
>burned off. I really didn't understand the point of that... ?? Do you do
>that? If so, why?
>
That is "rough annealing", commonly used with borosilicate tubing assemblies
made by scientific glass blowers.
The oxygen was turned off to get a lazy flame, to allow the work to be
brought to approximately the same temperature in the region of the join.
Then she just cleaned up the carbon deposit. With the low CofE (not Church
of England:-) that's enough to relieve any major stresses.
GlassOrchid
aquarium with little fishes and plants in it), which were on the largish
size. Maybe I'll email the author and ask why she did that with a bead. If
you're going to anneal in a kiln anyway, why would you do the 'rough
annealing' too... for a bead (as opposed to the tubing assemblies?).
Thanks Terry,
Nancy
"Terry Harper" <Terry....@btinternet.com> wrote in message
news:8a6ejh$3vk$1...@plutonium.btinternet.com...
Rascule
Maybe I can help with this question. When glass is annealed all the
molecules are happy little molecules all lined up in a row holding hands.
When an outside force is put upon them they get excited, expand, and start
to bump up against each other. This creates the stress. Stress in clear
glass can easily be seen with a polarascope. These forces are usually
thermal, but can also be physical. There is a term called "brusing of the
glass". This happens when glass is impacted but it doesn't break. ( IE
dropping it, something hitting it.) The impact point can be seen in the
polarascope as well. What the annealing process does is relaxes all the
molecules so they go back in a row thus releaving the stress, weather it is
thermal or physical stress. Having high stress in glass is a time bomb
waiting for a reason to let go. It could be anything from noise shock waves
(door slamming) to changes in the weather (thermal) to cause this. And there
is no way to predict a time frame for it to happen. Sometimes peices crack
for no reason....right? Well, maybe not concidering bad seals,
uncompatibilities, and brusing?
Now when comes to using colors, (especially soft glasses) you have to also
consider compatability of the glasses. Differences in compatibillity create
stresses in the glass. This is because of the "coefficient of expansion"
(how much the glass moves with each BTU of heat applied). It will vary with
each color even though they are concidered compatible. As you know the
colors work differently, some are stiffer than others. If you are using two
colors that are from both ends of the compatibility spectrum, you may have
great difficulty keeping them together if not annealed correctly.
Experienced bead makers know some colors work togather, and some don't.
Having some stress in glass is not a death sentence. Tempered glass is
purposely stressed. The idea is to releave enough stress so the peice will
stay togather. With multiple colors you will always have some stress, even
after kilm anealing.
Proper flame anealing, in my opinion, is 99% effective as using an oven, but
only in certain situations. These situations are if you are using
borocillicate (Pyrex) and the glass walls fairly are thin. ( or a light mass
of glass ) The heavier and more solid the mass of the glass, ( IE, heavy
wall, big beads, paper weights ect..) the more crucial the anealing process
becomes. The heavier the mass of glass, the slower the ramp rates, and
longer the soak time is needed. Vermiculite is simply not enough. In my
career I have jacketed (sealed internaly) 22 liter flasks (14" diam.)
within a 50 liter flask (18" diam.) and just flamed annealed it. Then turn
it around, reheat it, and work on the other end. All without throwing them
in a hot oven. We ran the oven at the end of the day.
Just buring it in vermiculite is not annealing it. So when you stick your
peice in vermiculite or a fiber blanket, you're capturing the heat from the
glass and slowing the cooling process down so as not to create high stress
in the glass from cooling to quickly. But you need to "anneal" it frist in
the flame. Balance the the whole peice to an even tempiture above the
strain point.
With small work this is fine. So to answer the question "When is it time to
anneal with a kilm?" the answer is " when your glass starts to break
without one" ...... Just keep in mind that kilm annealing may indeed add
years to the longevity of your work. However, some of the first glass known
to man was found in the tombs of the Fero's. It has survived all these years
and I suspect it was only flame annealed and buried in sand.
To explain the flame annealing trick in the video is like this....
For carbon to collect on glass the surface tempiture is below the strain
point. By heating it till the carbon burns off is bringing the tempiture up
past the strain point.
Keep in mind this is with borocillicate glass, and that it is just the
surface tempiture getting hot enough for this effect to happen. If the glass
is thick, you need to add time for the tempiture to equalize through the
entire peice. This trick actually works best using natural gas and oxy.
Propane is a dirty gas, and much hotter than natural gas. Making it harder
to judge.
Good luck to all,
Randy Hansen
Owner
SC Glass Tech.
(Southern California Glass Technologies)
San Diego, CA.
"GlassOrchid" <tna...@optonline.net> wrote in message
news:Yvix4.10$na4...@news.optonline.net...
> Bob (or anyone):
>
> How long does it take for cracks to appear in non-kiln-annealed beads?
I've
> been making beads since last summer and haven't had any that did crack*
but
> mine are pretty simple and not real large. I appreciate the advice; I
> taught myself lampwork from a book.... sort of leaves one wanting.....
>
> I just got a video on lampwork and the maker showed flame annealing (I
think
> that's what it was called) where she turned up the propane and the bead
got
> covered in black soot. Then she turned the oxygen back up and the black
> burned off. I really didn't understand the point of that... ?? Do you do
> that? If so, why?
>
>
> Nancy
>
> *some did crack but in the first 24 hours.... I'm talking about after
that.
>
>
> "Bobfuses" <bobf...@aol.com> wrote in message
> news:20000307204203...@ng-cv1.aol.com...
> > >Are fiber blankets enough? What determines when you really have to
start
> > >using an annealing kiln?
> > >
Randy Hansen
The annealing points of pyrex and soft glasses are actually fairly close in
temp. This would allow for this trick to work, but again only with small
pieces. It is the coefficient of expansion that varies greatly with these
glasses. Making them impossible to weld directly together.
Randy Hansen
Owner
SC Glass Tech.
(Southern California Glass Technologies)
"GlassOrchid" <tna...@optonline.net> wrote in message
news:bizx4.142$na4....@news.optonline.net...
> Hmmm.. the video was about making aquarium beads (beads that look like an
> aquarium with little fishes and plants in it), which were on the largish
> size. Maybe I'll email the author and ask why she did that with a bead. If
> you're going to anneal in a kiln anyway, why would you do the 'rough
> annealing' too... for a bead (as opposed to the tubing assemblies?).
>
> Thanks Terry,
> Nancy
>
>
> "Terry Harper" <Terry....@btinternet.com> wrote in message
> news:8a6ejh$3vk$1...@plutonium.btinternet.com...
> > GlassOrchid wrote in message ...
> > >
> > >I just got a video on lampwork and the maker showed flame annealing (I
> > think
> > >that's what it was called) where she turned up the propane and the bead
> got
> > >covered in black soot. Then she turned the oxygen back up and the black
> > >burned off. I really didn't understand the point of that... ?? Do you
do
> > >that? If so, why?
> > >
> >
bur...@attglobal.net
>Hello to all,
>
>Maybe I can help with this question. When glass is annealed all the
>molecules are happy little molecules all lined up in a row holding >hands.
Obvious influence from Bob Ross.
George Martin
understand that it works is that after you have taken the bead out of
the flam you put it into a kiln that is heated to about 900 degrees and
then alow them to cool slowly. This is what I know, it is how the other
lampworkers I know anneal their beads, hope this helps
Jessica
David Babb wrote:
>
> Hello all,
>
> I have been making beads now for a few months and am starting to
> have some that I would like to stay around for a while. My
> question is this... I do not yet have a kiln but was wondering
> if I could take a bunch of beads to a studio (ceramic or otherwise)
> and rent some kiln time. It would seem to me that any kiln with a
> controller could get the annealing temperature and cool down ramp
> correct. Also, if I have already taken the beads off the mandrels
> (but NOT cleaned out the bead release from the inside of the bead)
Terry Harper
>point. By heating it till the carbon burns off is bringing the tempiture
up
>past the strain point.
>Keep in mind this is with borocillicate glass, and that it is just the
>surface tempiture getting hot enough for this effect to happen. If the
glass
>is thick, you need to add time for the tempiture to equalize through the
>entire peice. This trick actually works best using natural gas and oxy.
>Propane is a dirty gas, and much hotter than natural gas. Making it harder
>to judge.
>
Nancy Block
>I have not begun to anneal my own glass beads yet but, the way I
>understand that it works is that after you have taken the bead out of
>the flam you put it into a kiln that is heated to about 900 degrees and
>then alow them to cool slowly. This is what I know, it is how the other
>lampworkers I know anneal their beads, hope this helps
> Jessica
>
I just remembered: Arrow Springs' web site has tips on working with glass, which
may well include annealing.
http://www.el-dorado.ca.us/~flameon/tips_tricks/tips_tricks.html
Nancy
GlassOrchid
to kiln anneal my small
simple beads or not, and I've gotten more information in some aspects than I
ever wanted <VBG> but I've got lots of ideas and places to research.
I have a very large glass kiln (oval) but think that's a bit over the top
to anneal a dozen or so beads... might just have to bite the bullet and
invest in a small bead annealing kiln.
Thanks all,
Nancy
"Nancy Block" <na...@dryad.ebay.sun.com> wrote in message
news:8a9o59$391$1...@ebaynews1.EBay.Sun.COM...
Bert Weiss
>
>I have a very large glass kiln (oval) but think that's a bit over the top
>to anneal a dozen or so beads... might just have to bite the bullet and
>invest in a small bead annealing kiln.
>
>Thanks all,
>Nancy
Nancy
Why not try to place the beads in your large kiln just before the annealing
soak starts, when you are doing a fuse firing Then they will anneal with
the rest of the kiln load. You could preheat the beads in a fry pan or on
a piece of stone or kiln shelf on a hot plate, and/or with a torch. If you
can figure out a technique to make this work you will get annealed beads
with no extra firings.
Bert
Bert Weiss Art Glass
Custom Productions
Furniture
Sculpture
Lighting
Tableware
Architectural Commissions
GlassOrchid
they were still on the mandrel. I guess not, huh?!
Thanks Bert, I might just try that.
Nancy
"Bert Weiss" <be...@customartglass.com> wrote in message
news:bert-ya02408000R...@news.landmarknet.net...
Bert Weiss
I'm not a bead maker, but as I understand the situation, a flame annealed
bead can live for a few minutes to a few thousand years depending on how
good the flame annealer is at guessing just what heat is required. People
have said that their beads usually last a while, but sometimes crack later
in life. If you get the bead reheated to beyond the strain point before it
cracks, you can then anneal it in the kiln, with some certainty. The trick
is to get it heated up , but not so much that it begins to mark and slump.
The one situation that is unannealable is incompatioble glasses mixed in
the bead.
The technique of coating the bead with carbon and heating it up just enough
to burn off the carbon sounds like a good one to me. You could then place
the bead in a 920-1050ºF kiln with your other work and let it all cool.
Timing is everything.
Steve - Linux Admin
>
> Hello all,
>
> I have been making beads now for a few months and am starting to
> have some that I would like to stay around for a while. My
> question is this... I do not yet have a kiln but was wondering
> if I could take a bunch of beads to a studio (ceramic or otherwise)
> and rent some kiln time. It would seem to me that any kiln with a
> controller could get the annealing temperature and cool down ramp
> correct. Also, if I have already taken the beads off the mandrels
> (but NOT cleaned out the bead release from the inside of the bead)
> can I just stick the bead back on the mandrel to be annealed? (or
> do you think that it will stick?) Any comments about what I can
> do until I can afford a kiln would be helpful.
>
> Specific question:
>
> I am using Moretti glass (annealing range of 920-968 F). Can anyone
> suggest the ramp-up, soak, and cool down times? (etc. 1hr, 20 min,
> 4 hrs?)
>
> Thank you all for your time.
>
> David
Straight from the beadmaking FAQ for this group:
After the bead is formed, it must be cooled slowly to avoid cracking
due to thermal shock. The most commonly used methods for avoiding
thermal shock are ceramic blankets, pre-heated vermiculite, and bead
annealing kilns.
When asbestos was found to contribute to certain nasty lung conditions,
alternatives were developed, and these ceramic fiber blankets are every
bit as effective as asbestos was, but much more user friendly. As soon
as the bead stops glowing, it can be set on a one inch blanket, and a
layer then folded over the top of the bead. Subsequent beads are then
laid close to, but not touching, previous ones.
Vermiculite is a well-known insulator as well. It can be used at room
temperature, but is more effective if pre-heated. This can be done in
various ways (coffee can on hot plate, wood stove, or kerosene heater)
so that when the hot bead is plunged into it, the immediate cooling rate
is less than it would be in cold vermiculite.
The best way to treat a bead right after you've made it, is to place it
into a kiln that's sitting at 800 degrees. When you've finished with
that
batch of beads, you can then take the kiln up to the annealing point of
the glass you're using, (968F for Moretti) let it soak at that
temperature
for several minutes, and then let it cool slowly over a period of a few
hours. (see the section on Kiln-formed glass for more on annealing)
The only way to insure your beads will be around for the next generation
to enjoy is if they are properly annealed. Even if you cool them very
slowly in the ceramic blanket, or heated vermiculite, that is really
only a stop-gap. There will still be internal stresses created when the
outside of the bead cools more quickly than the inside.
Many people who don't have a kiln use one of the slow cool methods, and
then when they get a sufficient quantity, take them to someone who has
a kiln for annealing.
The entire series of FAQ articles can be found at
http://people.delphi.com/stackman/faq.html and
http://www.riordanartistry.com/htm/faq/faqtitl.htm
--
Steve Ackman
Manager, New Age Forum http://www.delphi.com/newage
Glass Host, Arts & Crafts http://www.delphi.com/crafts
Metamorphosis Glassworks Page http://people.delphi.com/stackman
GlassOrchid
thanks to all of you.
Nancy
"Steve - Linux Admin" <stac...@XdelphiX.com> wrote in message
news:38C94974...@XdelphiX.com...
Randy Hansen
local PBS station .
<bur...@attglobal.net> wrote in message news:38c79...@news1.prserv.net...
> >Rascule wrote in message <8a6lmv$d...@chronicle.concentric.net>...
> >Hello to all,
> >
> >Maybe I can help with this question. When glass is annealed all the
> >molecules are happy little molecules all lined up in a row holding
>hands.
>
Barbara Otterson
wrote:
>Did I date myself? Yes I watched him many a Saturday when I was a kid on our
>local PBS station .
>
>> >
>> >Maybe I can help with this question. When glass is annealed all the
>> >molecules are happy little molecules all lined up in a row holding
>>hands.
>>
>> Obvious influence from Bob Ross.
>
No, that's not dating yourself. At least not to me, Bob Ross and
I were kids at the same time.
Barbara
Dream Master
+-------------------------------------------+
Sundog
Steve - Linux Admin > wrote <snip>
>When asbestos was found to contribute to certain nasty lung conditions,
>alternatives were developed, and these ceramic fiber blankets are every
>bit as effective as asbestos was, but much more user friendly.
Word of caution.... todays ceramic fiber insulations contain fibers of
various composition, and most are proven to be known carcinogens, so
adequate care in use is strongly advised. Read the material safety Data
sheets when included.... argh! Every now & then I breathe in one of two
of these pests and let me say.... the coughing response is worse than most
things I've experienced. I work with a variety of fiber board, blanket, and
paper in my fusing work, and 'loose fibers' from these products deserve some
serious respect..... they are NOT user friendly.
regards, Jacques Bordeleau ( Windows Sux.... can't wait for some user
friendly Linux)
Jim V
( Windows Sux.... can't wait for some user
friendly Linux)
<<<<<<<
May! now we are REALLY off topic!
--
- - - - - - - - - - - - - - - - - - - - - - - - - - -
Jim
jvorm...@socal.rr.com
Sundog
Jim V wrote in message ...
>>>>>>>>
>( Windows Sux.... can't wait for some user
>friendly Linux)
><<<<<<<
>Isn't that an oxymoron? You got the first part right, tho.
>May! now we are REALLY off topic!
hahahahahahaha........Sorry for OT reply also, but I can't help
myself........ I must point out desktop Linux is coming, along with some
decent STABILITY...I'm invested in a co. called Borland/Inprise that makes
cross-platform middleware for software developers, and they are bringing out
'Kylix' this year which is a tool developers will use to quickly convert any
Windoze application to the Linux platform. ....joy joy joy........ and Corel
has recently released a Linux desktop OS with Office & WordPerfect
applications that practically installs itself, so folks like me can get up &
rolling..... I'm just waiting for the software world to appear with Linux
programs for everything I do now. In fact just yesterday Corel announced a
FREE download of Photopaint 9 for Linux.
I've been on Win NT for a couple years so I only crash every week anymore,
but I still remember what drawing in Win95 was like.... crash 4 times a day.
The end to MS 'Bloatware' is coming. Win 2000 debuted with 63,000 known
bugs still in it, and requires 128 MB Ram just to run.... but 256 MB works
better, an MS exec was quoted as saying.............. HA!!!!!!
regards, Jacques Bordeleau
Mellmang
love ya Bob,
mellmang
Bobfuses
>paper in my fusing work, and 'loose fibers' from these products deserve some
>serious respect..... they are NOT user friendly.
>
>regards, Jacques Bordeleau
I'll second that. Whenever I am cleaning the shelf side of glass fired on fiber
paper I do so under running water. Wetting the fiber keeps it out of the air I
breath.
I also wear a resperator when sanding a new fiber mold. Otherwise, I just
handle with care.
Bob in 92026
Miracle >^,,^<
Mellmang wrote...
> R.I.P Bob Ross. One of the last good guys.
I miss PeaPod the Pocket Squirrel
nearly as much as I do Bob. Bob Ross
was truly a good guy.
Miracle (Who apologizes for being off-topic,
but who also misses Bob very, very much.)
Cheryl
Like someone said, if you put just-formed glass in a bucket of sand, cover
it and leave till it's cooled down, you have probably annealed it
adequately.>>>
NO - you haven't.
DO NOT believe that mis-statement.
Get Bandhu Scott Dunham's book on lampworking, and read the info on annealing.
Or get Jim Kervin's
Everything you wanted to Know about Beadmaking - and read it.
crock pot, sand, vermiculite methods - etc
ARE NOT ANNEALING!
Cheryl of DRAGON BEADS
Flameworked beads and glass
http://www.dragonbeads.com/
Terry Harper
>
>crock pot, sand, vermiculite methods - etc
>ARE NOT ANNEALING!
>
will be annealed.
It's a method that has been used for centuries.
Steve - Linux Admin
>
> Steve - Linux Admin > wrote <snip>
> >When asbestos was found to contribute to certain nasty lung conditions,
> >alternatives were developed, and these ceramic fiber blankets are every
> >bit as effective as asbestos was, but much more user friendly.
> _________________________________________________________
>
> Word of caution.... todays ceramic fiber insulations contain fibers of
> various composition, and most are proven to be known carcinogens, so
> adequate care in use is strongly advised. Read the material safety Data
> sheets when included.... argh!
Right. "Much" more user friendly is undoubtedly too optimistic.
"Somewhat" would be more accurate.
> regards, Jacques Bordeleau ( Windows Sux.... can't wait for some user
> friendly Linux)
Linux has been user-friendly for years. ;-)
(try Corel Linux, or Caldera OpenLinux. Both are supposed to be
practically self-installing)
Steve - Linux Admin
> hahahahahahaha........Sorry for OT reply also, but I can't help
> myself........ I must point out desktop Linux is coming, along with some
> decent STABILITY...
Even when you have a "crash" it's generally not the entire OS
that crashes. I've had my X server crash only rarely, meaning
I had no mouse or keyboard. Very frustrating for the time
being, but the gateway to the internet keeps on trucking, so nobody
else on the network is even aware anything is wrong.
> and Corel
> has recently released a Linux desktop OS with Office & WordPerfect
I've been using WP8 on Linux since Christmas '98. I don't
know what Office is... so I most likely don't need it. ;-)
> applications that practically installs itself, so folks like me can get up &
> rolling..... I'm just waiting for the software world to appear with Linux
> programs for everything I do now. In fact just yesterday Corel announced a
> FREE download of Photopaint 9 for Linux.
I use and love GIMP for nearly all my complex photo enhancement
and manipulation. For quick'n'dirty jobs, xv is much smaller and
faster.
I really don't even see a need for something like Photopaint for
Linux... but whatever you're comfortable using is the best thing
to use. ;-)
> I've been on Win NT for a couple years so I only crash every week anymore,
I generally get to uptimes of 40 days or so before I need to
boot to DOS for some reason or other, or do hardware upgrades,
or move.
> but I still remember what drawing in Win95 was like.... crash 4 times a day.
I've never owned Windows; never will.
> The end to MS 'Bloatware' is coming. Win 2000 debuted with 63,000 known
> bugs still in it, and requires 128 MB Ram just to run.... but 256 MB works
> better, an MS exec was quoted as saying.............. HA!!!!!!
My uptime shows 20 users right now, and I'm doing it on 24MB RAM.
When one or more users run something intensive like GIMP, things slow
down a bit, but not unbearably so.
And just to get this back around to glass, I do just about all my
geometric pattern drawing on GeoDraw in DOS (one of the reasons I
occasionally reboot), but Linux has a program which looks like it might
have similar capabilities, called fig. I've played with it a bit, but
you get used to a certain program, and get to like 'em, it's hard to
switch if you don't absolutely have to.
db
thank you for including a hint toward your topic in the subject line so we
can ignore it. But while we're here, maybe there's a dedicated SNMP MIB for
glass kilns and controllers? You could shoot a trap out to Openview or
Tivoli when a firing event occured. Yea, and then have it kick-off a shell
script (Korn shell rules, by the way) to animate what you hope is happening
inside your kiln. Of course would have to have a portable agent for
monitoring remotely. Would give new meaning to the requirement for a
'firewall'.
--
----------------------------------------------------------------------------
--
Don Burt - Disinclined AIX Administrator
----------------------------------------------------------------------------
--
Frogacuda Productions -
Jim V
slow cooling and annealing, which is a process of cooling the glass to a
point just above its stress point, and leaving it there for the amt of time
it takes the stress to even out. THEN the slow cooling takes place. That
soak temperature is very specific for each kind of glass you might work
with, and you need to kwon what it is for the glass YOU use.
Beads can be slow cooled in blankets-sand-vermiculite IF they are small
enough to not have a significant amount of strain in them. A
heavier/thicker piece will be much more likely to not survive.
As she said... check the authorities.
Steve - Linux Admin
>
> Unix sickos pervade even arts/crafts newsgroups, it seems. At least we can
> thank you for including a hint toward your topic in the subject line so we
> can ignore it.
Well, so most people can ignore it anyway. ;-)
>But while we're here, maybe there's a dedicated SNMP MIB for
> glass kilns and controllers?
I read something on another group that leads me to believe that
it should be possible to turn a sound card into a kiln controller.
Obviously it would have to be coupled with a thermocouple and the
SSR/SCR being discussed at length in another thread, but the idea
of giving new life to old cast-off 386/486 class machines appeals
to me. The number of ramps and programs would be practically
unlimited compared to conventional dedicated kiln controllers.
> You could shoot a trap out to Openview or
> Tivoli when a firing event occured. Yea, and then have it kick-off a shell
> script (Korn shell rules, by the way) to animate what you hope is happening
> inside your kiln.
You'd probably want to use tcl/tk for graphics, and of course
bash is the real shell. ;-)
> Of course would have to have a portable agent for
> monitoring remotely. Would give new meaning to the requirement for a
> 'firewall'.
I can hear it now. Since your controller is a sound card,
run the output also to your stereo.
"Man! What is that awful noise?"
"Oh, it's just the way I monitor my kiln."
> ----------------------------------------------------------------------------
> --
> Don Burt - Disinclined AIX Administrator
> ----------------------------------------------------------------------------
Disinclined?
Neon John
Steve - Linux Admin wrote:
> I read something on another group that leads me to believe that
> it should be possible to turn a sound card into a kiln controller.
> Obviously it would have to be coupled with a thermocouple and the
> SSR/SCR being discussed at length in another thread, but the idea
> of giving new life to old cast-off 386/486 class machines appeals
> to me. The number of ramps and programs would be practically
> unlimited compared to conventional dedicated kiln controllers.
I'm not sure about a sound card but with a game controller card, it
is duck soup simple. As it is with a parallel port. Been there,
done that, worked fine.
>
> > You could shoot a trap out to Openview or
> > Tivoli when a firing event occured. Yea, and then have it kick-off a shell
> > script (Korn shell rules, by the way) to animate what you hope is happening
> > inside your kiln.
>
> You'd probably want to use tcl/tk for graphics, and of course
> bash is the real shell. ;-)
Aw man, Bash users ain't safe around sheep! Korn rules, amen
brother!
John
--
John De Armond
johngd...@bellsouth.net
http://neonjohn.4mg.com
Neon John's Custom Neon
Cleveland, TN
"Bendin' Glass 'n Passin' Gas"
db
> clip:
>Obviously it would have to be coupled with a thermocouple and the
>SSR/SCR being discussed at length in another thread
> I can hear it now. Since your controller is a sound card,
>run the output also to your stereo.
> "Man! What is that awful noise?"
> "Oh, it's just the way I monitor my kiln."
>clip
So what wave table sound do we use for when the glass finally flows? I'm
thinking something like a Nicole Kidman moan. Or maybe a slow Homer Simpson
'mmmm doughnut'.
> Disinclined?
Yes, disinclined. No business-casual beeper-bound oracle/aix/rs6000
administrator for an insurance company here. I'm an arteest. A glass guy
with a major ponytail. I even have an 'artists statement' that mentions
Nietzsche. Really.
Sundog
hehehehehehehehe hehehehe hehehe ha
OK, I want to know EXACTLY how to make an old 486 into my next kiln
controller. I want words. I want drawings. And I want it in lay
terms............. (please)
Thanks in advance.......................... ;-)
Jacques Bordeleau
db
> controller
I could collaborate on it, write the programs maybe. But I couldn't design a
computer system to program controllers. I quit reading that controller
thread with those guys from a different planet talking about phases and
milliamps and cycles and such. I turn my kiln on with two dials, and I'm not
even 100% sure how they work. But give me some specs, I could turn out the
code. Actually, given that amount of spare time, would rather sort scrap
glass.
--
----------------------------------------------------------------------------
--
Don Burt - Design/Fabrication
----------------------------------------------------------------------------
--
Frogacuda Productions - www.frogacuda.com
Sundog <alw...@mybest.com> wrote in message
news:sd8k02...@corp.supernews.com...
Sundog
OK Don___ I'm filing your post away till I need to do this. I plan a box
about 30 x 120" in the next year I hope. I'm thinking multi-zone elements,
to keep the overall temp even for anneals. I have built a box 25 x 55, and
expect problems may occur exponentially to relative size with the next one.
regards, Jacques Bordeleau
Neon John
Sundog wrote:
>
> hehehehehehehehe hehehehe hehehe ha
>
> OK, I want to know EXACTLY how to make an old 486 into my next kiln
> controller. I want words. I want drawings. And I want it in lay
> terms............. (please)
>
> Thanks in advance.......................... ;-)
>
> Jacques Bordeleau
go to B&B electronics (web site by approximately that name) and buy
a thermocouple to parallel port converter for about $100 or so.
Plug that into one parallel port. To a second parallel port,
connect a suitable solid state relay to one of the data bit leads.
When you write a 1 to that bit, the relay turns on, when you write a
0, the relay turns off. Use that SSR to control a mercury
displacement relay that controls the kiln. Then all that remains is
to write some (preferably DOS) code to implement the controller.
B&B sells the source code for simple PID controller for about $50,
last time I checked. With that code in hand, all that remains is a
user interface.
An alternative to the B&B module is to use the joy stick port to
digitize an amplified TC signal. Not nearly as accurate but damn
nearly free.
I built something similar and hacked out the code to run profiles
contained in files over one weekend. No, the code is long gone,
victim to one too many windoze crashes.
Sundog
next question is, would this then be expandable within the one computer to
run 3 to 5 'zones' within a large kiln, each zone being a separate circuit &
thermocouple, in order to maintain even heat throughout the kiln? This
concept is limited by the number of ports the computer has, isn't it?
Related idea then.... since the Digitry Controller can run 5
kilns/annealers, it would easily run 5 zones in one box, yes? (Actually I
think 3 zones will do the job for me at about 38 x 120"). I may even try to
add a removable partition within the box to work shorter projects without
firing the whole shebang every time.
thanks, Jacques Bordeleau
________________________________________________
Neon John wrote >
Neon John
Sundog wrote:
>
> John__ thanks, sounds actually do-able, at least explainable to my tech. My
> next question is, would this then be expandable within the one computer to
> run 3 to 5 'zones' within a large kiln, each zone being a separate circuit &
> thermocouple, in order to maintain even heat throughout the kiln? This
> concept is limited by the number of ports the computer has, isn't it?
yes. It is easy to bring up to 8 analog signals into a PC because
there are so many good A/D converters with 8 muxed inputs. There
are lots of companies that make inexpensive converters. As usual,
Omega engineering is a good place to look and maybe buy if you don't
need the absolutely lowest price. They resell others' products so
you can probably find a product elsewhere after you find it at
Omega. On the output side, you can drive up to 10 loads on and off
from a PC parallel port (8 data bits plus 2 status lines.). B&B
makes a nice little fan-out box for the parallel port that provides
8 buffered outputs plus dome source code to manipulate the parallel
port. You can easily put 2 parallel ports and 4 serial ports in a
PC. You can put more than 2 parallel ports of you don't mind
futzing around a bit and perhaps removing other unused resources.
Beyond that, B&B and others make output multiplexers (MUXers) that
will drive a practically unlimited number of devices from a single
parallel port.
Another option for input is to use the Basic Stamp single board
computer (less than $100 from Digikey, http://www.digikey.com) as
the front end. The code is written in BASIC, downloaded to the
Stamp over a serial line and stored in Flash RAM. The Stamp then
runs and does its thing. It is pretty trivial with the Stamp to
read up to 8 thermocouples, converter the data and ship it out the
Stamp's serial port to the PC. They call it the Basic Stamp because
it's about the size of a postage stamp.
>
> Related idea then.... since the Digitry Controller can run 5
> kilns/annealers, it would easily run 5 zones in one box, yes? (Actually I
> think 3 zones will do the job for me at about 38 x 120"). I may even try to
> add a removable partition within the box to work shorter projects without
> firing the whole shebang every time.
Dunno. I've always built my controllers so I'm not terribly
familiar with commercial units.
db
source code. What I don't get is all the talk about 'learning' programs that
can anticipate when to fry and when not, and phasing and milliamp this and
that. If the task at hand is simply to turn relays on and off, and to read a
thermocouple signal, then you could probably even use the stuff for
household appliance control, like at www.x10.com. Although John's suggestion
of B&B looks like a better place to start. They make a good brandy too.
--
----------------------------------------------------------------------------
--
Don Burt - Design/Fabrication
----------------------------------------------------------------------------
--
Frogacuda Productions - www.frogacuda.com
Neon John <johngd...@bellsouth.net> wrote in message
news:38D80C1D...@bellsouth.net...
Neon John
db wrote:
>
> I noticed that most of the books on programming parallel ports include
> source code. What I don't get is all the talk about 'learning' programs that
> can anticipate when to fry and when not, and phasing and milliamp this and
> that. If the task at hand is simply to turn relays on and off, and to read a
> thermocouple signal, then you could probably even use the stuff for
> household appliance control, like at www.x10.com. Although John's suggestion
> of B&B looks like a better place to start. They make a good brandy too.
:-)
One could use an X-10, though the duty cycle for controlling a kiln
would probably wear it out fast, at least for the relay-out module.
For things like phase angle and such, the short answer is, you let
the mfr who makes the switch or controller worry about that.
There are broadly two styles of control. The first is on-off. This
is the control you have in your house for heat and cooling. When
the house gets colder than the thermostat setpoint, the furnace
turns on. Full on, not partially on. When the house warms up
enough to surpass the thermostat setpoint by a little, the furnace
turns full off. If the weather is very cold, the "ON" time will be
longer than the "OFF" time. If only a little heat is required, the
"OFF" time will be more than the "ON" time.
The second type of control is proportional. In this type of
control, the output varies in proportion to the difference between
the setpoint and the sensor. In the case of a kiln, that means that
the power sent to the heating elements is proportional to the
difference between the kiln and the desired temperature. In manual
terms, you would be watching the temperature indication and setting
the power level proportional to the difference between what
temperature you want and what you have. It should be intuitive that
the higher the gain between input and output, the better the
control. That is, the smaller temperature differential required to
produce the full swing in heater power, the tighter the temperature
will be held to setpoint. This hold true until the gain becomes so
high that the temperature overshoots from stored heat in the
element. Then the system will oscillate around the setpoint just
like an on-off controller. This is, of course, undesirable because
it defeats the inherently finer control of proportional control.
Since the error between setpoint and the actual temperature is what
is amplified to generate the output, it is again intuitive that some
error is necessary to be amplified to drive the output. If the load
becomes higher (opening a vent or whatnot), then the error must be
higher to generate more output to fire the heaters higher. Assuming
that we chose proportional control because we wanted the temperature
to be controlled quite closely, it is undesirable to have this error
or "offset". The solution is to use the error to periodically
internally shift the setpoint until the error between the measured
and set temperature. This is the same effect as if you watched the
temperature indicator and slowly nudge the indicator up until the
indicated temperature is what you wanted it to be. A controller
that does this automatically is said to have "reset" action (old
term) or "integral action". Mathematically, it integrates the error
term and adds it back in to the setpoint to force the measured
temperature to the original setpoint. With the integral action set
low, the setpoint will creep up on the setpoint. With too much
integral action, the temperature will overshoot because the setpoint
correction was too great, and then it will either settle down with
some oscillation or will continue to oscillate if way too much
integral is set. Any overshoot in a glass kiln is not desirable
(think: glass running everywhere!) so integral is used with caution.
Now suppose you open the kiln and insert a cold object. (think of a
lehr with a continuously moving belt.) In order for the heater
output to be increased to make up for this load, the temperature
must drop to generate an error signal. This may negatively affect
things already in the kiln. Suppose we could anticipate that
increase load and jack up the heat ahead of time. We can. If we
were manually controlling the system, all we'd need to do is to
watch the temperature and when the very first change is evident,
crank in extra power depending on how fast the temperature is
changing. Mathematically, what we're doing is taking the time
derivative of the input. The rate of change of the temperature is
analyzed and an additional output signal is developed that is
proportional to the rate of change of the input. The old term for
this is "rate action". The new term is "derivative action".
We've worked around to defining a commonly bantered about term.
When a controller has Proportional, Integral and Derivative action,
it is a PID controller. PID control has been around for 100+ years,
implemented in pneumatic (air operated) controls before the
development of electronics.
When a PID control is properly adjusted for the right amount of P, I
and D, a disturbance in the load results in only a slight, momentary
droop, a very slight overshoot as it adapts and and then quick
settling to the setpoint again. If it does it in an oscillation and
a half, it is "critically damped". This is generally regarded as
the best control, though for processes like glass working where any
overtemperature may be destructive, the system may be set to recover
to setpoint slightly slower in order to not have any overshoot.
Getting everything set correctly is called "tuning" and
traditionally required a very skilled instrumentation technician.
Like the buggy whip maker, this job has been obsoleted to a great
extent by modern technology. A "Self-Tuning" controller is one that
will measure the transfer function of the process (how much and when
the temperature changes for a change in input power), compute PID
coefficients and apply them to the PID control loop. One type of
self-tuning controller requires a perturbation in the process to
learn the transfer function. This is typically done by putting the
controller in "learn" or "self-tune" mode and then starting the kiln
up without any glass in it. The temperature will significantly
overshoot as the controller learns how to control the system. Once
tuned, it will adapt to changing conditions. Better controllers
will learn the transfer function from normal kiln operation and will
continuously tune itself for the best operation.
Commercial self-tuning techniques are highly proprietary, though
theoretical treatment is given the topic in the textbooks.
Typically, for using a PC as a controller, one either buys or
scrounges working self-tuning PID control code. B&B sells PID
control code quite inexpensively. I'm sure it's also out there on
the net somewhere. All you really need to know is that the PID
controller is a black box that takes input (temperature), generates
output (heat demand) and behaves as I described.
The normal method of proportionally controlling the power applied to
a process is to use a linear actuator. For heat, that might be a
device that takes the proportional output signal from the controller
and converts that into some end effect, say, power to a heater. A
phase angle controller is an example of such a device. In response
to an input signal, it varies the power delivered to the heater by
varying where on the 60 hz sine wave the power is turned on (phase
angle control). This is done 120 times a second. A variation on
this technique is to switch whole cycles of power to the heater. If
we arbitrarily select 1 second as the cycle interval, then we could
achieve the lowest power by switching 1 cycle out of 60 (for 60 hz
power) to the load and get the most power by switching all 60 cycles
to the load. The advantage to this technique is that the power is
switched only when the voltage is crossing zero so there is no
electrical noise generated. Such noise can interfere with other
electronic equipment. This is called zero crossing switching.
When the end effector (power controller) is separate from the PID
controller, the industry standard analog method of conveying demand
to the controller is via a 4 to 20 milliamp current loop. When the
controller wants zero power, it outputs 4 ma. When it wants maximum
power, it outputs 20 ma. 4 ma instead of 0 ma is chosen so there is
a "live zero". If there weren't, a wire break could be confused
with no demand. Most instruments detect "below zero" as a loop
break. This same scheme is used to convey measurements from the
field. A common instrument is a thermocouple to current converter.
It generates a current signal proportional to the temperature of the
thermocouple. A 4-20 ma current loop can transmit the information
over miles of wire. It is overkill for most kiln installations so
it is seldom seen in glass shops.
Because the kiln has a lot of thermal inertia (it doesn't
immediately cool off when the power is turned off), we can take
advantage of that fact to greatly simplify the control system.
Above we talked about zero crossing and switching individual cycles
of AC. We don't need that degree of control. Suppose we set the
cycle interval to 20 seconds instead of 1 second. For minimum heat
input, we might turn the power on for 1 second out of 20 while for
full output, the power would be on for the whole time - on
continuously. This is called proportional on-off control and is
implemented in many self-contained temperature controllers. Instead
of a 4-20 ma output signal, the controller outputs a contact
closure. The output is either on or off. This control signal
typically operates a relay. 20 seconds is a typical cycle time. The
cycle time is settable in most controllers. When minimal heat is
needed, it turns the relay on only a small amount of time over each
20 second interval. If half power is needed, the relay would be on
for 10 seconds and off for 10 seconds.
Though an ordinary relay or power contactor can be used, it will be
noisy and will quickly wear out. Typically a mercury displacement
relay is used. In this relay, power is switched by magnetically
moving a plunger which separates or connects two pools of mercury.
Since the mercury is liquid, there are no contacts to wear. And
since the plunger is inside a closed mercury capsule, the relay is
almost silent. Typically only a small "thunk" is heard on each
operation. Life is essentially forever. The solid state version of
this is the Solid State Relay (SSR) or solid state contactor. The
only advantage the SSR or SSC brings is it is totally silent and
theoretically will last longer since there are no moving parts. The
negative is, sensitive electronic parts are involved that can be
smoked by lightning and other transients, and the device is much
more expensive than the mercury displacement relay.
Closing the loop, so to speak, when we talked about a PC controller,
what we'd be doing is using the PC to implement the PID control.
Some sort of external converter converts the thermocouple signal
into a digital value. Proportional on-off control is achieved by
turning a data bit on the parallel port on and off. This line is
used to control either a mercury displacement relay or an SSR/SSC.
How's that for a control theory short course? :-) See, it's not
that complicated. BTW, an infinite control is really a little
self-contained manually operated proportional on-off controller.
John
db
>
> clip small book
>
> How's that for a control theory short course? :-) See, it's not
> that complicated. BTW, an infinite control is really a little
> self-contained manually operated proportional on-off controller.
>
Outstanding. Thanks for taking the time and sharing the info.
Sundog
Neon John wrote >
>How's that for a control theory short course? :-)
Wow!................... thanks. ;-o I bet at least some of this comes
into great value for me over the years ahead.
That was quite an effort to write all that. I'm just amazed that anyone can
actually know all that stuff.... but then it's not my field...right? I'm an
aesthetics specialist, and I learn what I need to in the course of my work,
to evolve into my goals.
kindest regards, Jacques Bordeleau
Bobfuses
be...@customartglass.com (Bert Weiss) writes:
>You could preheat the beads in a fry pan or on
>a piece of stone or kiln shelf on a hot plate, and/or with a torch. If you
>can figure out a technique to make this work you will get annealed beads
>with no extra firings.
>
>Bert
I'm reading this off line and so can not look it up but a few months ago
someone posted a site that gave instructions for making an annealing chamber
from a light fixture available in hardware stores. It was a halogen light as I
recall. Do a deja.com search to find the post. Anyone that finds it please post
site here.
When I read the site it seemed to me that for US$20.00 one could make a
workable annealing chamber for beads.
Bob, In Las Vegas for Glass Craft Expo 2000.
Bob in 92026
cosmo
http://members.aol.com/HRHOSMER/Tech_Page.html
I found it linked from the SGB website, which also has some
very good info about annealing your beads in the FAQ section.
Good luck,
Alexandra
Darleen Michael-Baker
>
> I'm reading this off line and so can not look it up but a few months ago
> someone posted a site that gave instructions for making an annealing chamber
> from a light fixture available in hardware stores. It was a halogen light as I
> recall. Do a deja.com search to find the post. Anyone that finds it please
> post
> site here.
>
> When I read the site it seemed to me that for US$20.00 one could make a
> workable annealing chamber for beads.
>
> Bob, In Las Vegas for Glass Craft Expo 2000.
> Bob in 92026
http://members.aol.com/HRHOSMER/Tech_Page.html
--
Darleen
The future belongs to those who prepare for it.
--Ralph Waldo Emerson
<http://www.homebusiness.to/darleenmb>