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Lyssa
2011-10-21, 10:28am
Hi all, some of the beads that came out of my batch anneals in the last two days are partially devitrified. Does anyone know what is causing this and how can I prevent it?

I've heard people say you can soak devitrified beads in stuff to get the devit off, is that true and what stuff do I use?

Thanks!

DreamMuse
2011-10-21, 11:37am
I had that happen with opaque cobalt beads that I batch annealed, before I got my kiln. I remember asking what caused it, and no one ever had a perfect answer. Since the kiln I was using had a tight seal on the door, it was assumed that I had a reduction atmosphere in the kiln. Unfortunately, I don't think there's a solution for that. I've heard of adding charcoal in a dish on the kiln floor, but I think that's to preserve a reduction atmostphere, if the kiln is removing the shine off your reduction glass beads.

I ended up etching them to remove the devit, but hopefully someone else has a better solution for you.

For what it's worth, it doesn't happen now that I have a toolbox kiln and garage them immediately. But opaque turquoise still will get that reduction.

Lyssa
2011-10-21, 11:46am
Thanks Disa, when I did a search for "anneal+devit' it came up with your 2005 thread. I saw all those answers and you're right. No one actually said how to prevent it. I don't remember exactly which thread I read, but there was a *hint* that it might be caused by going up too high, or maybe going down too fast... but again, that was just a *hint* I got from some of the posts. Not sure if I was gleaning the truth or not.

Lisi
2011-10-21, 1:26pm
Devitrification does not happen out of the flame. It is a change in the chemical composition on the surface of the beads while they are being worked in the flame. Very few glass colors devit, and here is a handful of the familiar ones:

Effetre Purple 254 aka EDP or "evil purple"
Effetre Sedona
Zimmerman Purple Rose which is rare and hard to find now
Old stock of Vetrofond black has done it

What you have is something else and it's not devitrification. It is probably reduction effects aka scum, greyish scum, copper build-up, there are many names for it. It may not actually look grey in color, but on dark colored beads, it leaves a dull, patchy, or non-shiny finish. You can probably remove it just fine with a solution of toilet blow cleaner.

Here it is:

Two parts Toilet Duck or Snobol toilet bowl cleaner mixed in one part water. Store in a plastic jar with good fitting lid, to be used over and over again. If you don't have a plastic jar on hand, you can store it in a glass jar temporarily. I had mine in an olive jar for a long time, but it's really better to have it in plastic. It will "eat" glass over time. ;)

String your beads on fishing line with a "stopper" at the end, I use an E bead or a pony bead. Dip them in the solution and leave them in for 15-20 minutes, and check after rinsing them in warm water. Use dish soap to wash them thoroughly to get all residue of the cleaner off.

Do you have a picture of these beads?

Lisi
2011-10-21, 1:29pm
Oh, I forgot to mention - the other day when I annealed copper green beads, they turned a greyish green and a little dull. They weren't that way going in the kiln. I cleaned them up bright and pretty like copper green is supposed to me, with the solution. :)

Lyssa
2011-10-21, 1:57pm
Thanks Lisi, I'm trying to get a picture from my phone to my computer. Let's see how that works out. :) The wi-fi here at work ain't so great.

Jody Lee
2011-10-21, 2:08pm
I had a bead fall behind my mandrel rack once and it probably had around 50 firings before I found it. It was pea green, and the shiny-ness had come off, leaving a finish much like devit on edp. I suppose it was from the rapid ramp up. It was certainly well annealed LOL :)

Lyssa
2011-10-21, 2:11pm
I'm amazed the bead didn't crack with its first rapid ramp up! LOL

I had a bead fall behind my mandrel rack once and it probably had around 50 firings before I found it. It was pea green, and the shiny-ness had come off, leaving a finish much like devit on edp. I suppose it was from the rapid ramp up. It was certainly well annealed LOL :)

Lyssa
2011-10-21, 4:09pm
Here's a picture of what's coming out of my annealer:
http://www.lampworketc.com/forums/picture.php?albumid=511&pictureid=4651

Devitrification does not happen out of the flame. It is a change in the chemical composition on the surface of the beads while they are being worked in the flame. Very few glass colors devit, and here is a handful of the familiar ones:

Effetre Purple 254 aka EDP or "evil purple"
Effetre Sedona
Zimmerman Purple Rose which is rare and hard to find now
Old stock of Vetrofond black has done it

What you have is something else and it's not devitrification. It is probably reduction effects aka scum, greyish scum, copper build-up, there are many names for it. It may not actually look grey in color, but on dark colored beads, it leaves a dull, patchy, or non-shiny finish. You can probably remove it just fine with a solution of toilet blow cleaner.

Here it is:

Two parts Toilet Duck or Snobol toilet bowl cleaner mixed in one part water. Store in a plastic jar with good fitting lid, to be used over and over again. If you don't have a plastic jar on hand, you can store it in a glass jar temporarily. I had mine in an olive jar for a long time, but it's really better to have it in plastic. It will "eat" glass over time. ;)

String your beads on fishing line with a "stopper" at the end, I use an E bead or a pony bead. Dip them in the solution and leave them in for 15-20 minutes, and check after rinsing them in warm water. Use dish soap to wash them thoroughly to get all residue of the cleaner off.

Do you have a picture of these beads?

squid
2011-10-21, 4:13pm
Actually, devit does happen in the kiln as it is often a problem with kiln fired glass - but it's usually in a temperature range above annealing temps. A funky atmosphere in the kiln can cause devit - I would suggest propping your door open slightly when ramping up.

A good article here:

http://www.clearwaterglass.com/Tutorials/Devitrification.html




Table 1: General causes of devitrification

Inadequate cleaning of the glass

Firing too hot and too long

The type of glass used is prone to devit

The glass has been fired more than once

The atmosphere in the kiln

Lyssa
2011-10-21, 5:04pm
Great article. It's making me think that we're comparing apples and oranges that happen to have both been genetically engineered from a banana. I think that regardless of which chemical reaction is causing the change in appearance of my beads (as opposed to EDP's devit in the flame, for instance), the change to my beads can be called devitrification, which just means that the glass has lost its glossiness.

Just a thought.

Thank you for the article, it's helping. :)

Actually, devit does happen in the kiln as it is often a problem with kiln fired glass - but it's usually in a temperature range above annealing temps. A funky atmosphere in the kiln can cause devit - I would suggest propping your door open slightly when ramping up.

A good article here:

http://www.clearwaterglass.com/Tutorials/Devitrification.html




Table 1: General causes of devitrification

Inadequate cleaning of the glass

Firing too hot and too long

The type of glass used is prone to devit

The glass has been fired more than once

The atmosphere in the kiln

Lisi
2011-10-21, 6:55pm
I think the article is referring to kiln fired glass, which is fired hot enough to melt. Therefore, glass that gets hot enough to have devitrification problems. That makes sense to me. But not with the temps used for annealing lampwork beads.

I have used every type of glass imaginable, made thousands upon thousands of beads for nine years, ran the kiln for 12-16 hours at annealing temp, and never had a bead with devitrification problems. Only certain colors like EDP would get this from working it in the flame and getting the glass too hot. I've had plenty with reduction scum, the dull surface which is easily cleaned up. Sometimes I could go back in the flame and get EDP shiny again, but the devit would still show around the holes. Those familiar with EDP and Sedona know exactly what I'm talking about.

Besides, if a kiln temp for annealing beads is "too hot", don't you think the beads would slump?? I have never heard of beads getting devitrification from annealing.

What is the base color of the bead? Is that copper green?

DreamMuse
2011-10-21, 9:26pm
Devitrification does not happen out of the flame.
But not with the temps used for annealing lampwork beads.

Yeah, I'll respectfully disagree *chuckles* That dark cobalt order of beads got the devit specifically from the batch annealing in my kiln. They were pristine and beautiful after cooling in vermiculite. It was the only color that got devit from my schedule in my closed kiln, aside from the other colors that get devit with the torch, like turquoise.

Aimee, that looks like the same nasty scum I got on those cobalt beads. Are you using a closed kiln like the AIM kiln that caused mine? I never did find a solution. That was an impetus for my getting a toolbox kiln to garage them immediately.

Lisi
2011-10-22, 3:05am
Cobalt? What glass, and do you mean the transparent cobalt? Effetre? The reason I ask is that some people refer to the opaque lapis blues as cobalt.

That's weird, I've never seen or read about any problems with transparents getting a dull surface after being in the kiln. Like I said, the turquoises and copper green were the scummy ones because of the copper.

jaci
2011-10-22, 6:22am
What kind of kiln do you have???
Try vacuuming out your kiln, and if brick coating it with a thin layer of kiln wash.
Over time if you have had lots of metals (silver glass beads, beads with silver leaf, reduction stuff, coper mesh, etc) You can get a build up of 'stuff' in the kiln walls. it just needs to be cleaned usually. I dont think there is an easy way to 'clean' the fiber blanket insulation w/ out replacing it, or taking a layer off basically (i do not recommend this, if you dont know what you are doing)

The other possibility is that your kiln is running hot, or you are putting beads into the kiln too hot/cold and they are adjusting to the temp causing the reaction(probably not the answer here looking at your bead). Try turning it down 10-20 degrees (start with 10 and go from there). Try cooling your bead more before you put it in the kiln.

DreamMuse
2011-10-22, 10:08am
Ahh, yes, it was the pastel lapis. The "official" name is P-246 Lapis Cobalt Blue, so I always just said Cobalt.

Lisi
2011-10-22, 6:39pm
Ahh...seems to me I read something somewhere about lapis being an occasional troublemaker. Have you tried soaking the lapis beads in Coke (Pepsi is better) overnight or the 15 minute toilet bowl and water solution? (2 parts to 1 part H2O)

DreamMuse
2011-10-22, 9:56pm
Well, this was several years ago, so I don't have the beads anymore. I never did find a solution for the batch annealing problem, and I got a toolbox kiln soon after which didn't create the problem.

I did try soaking the beads in toilet cleaner, and jeweler's pickle. Neither really helped.

http://www.lampworketc.com/forums/showthread.php?t=1936

But even if it was due to the cobalt, why would Lyssa's pea green do it, I wonder? That is pea green, isn't it Lyssa?

Lyssa
2011-10-23, 12:30pm
CIM Olive. Other beads that were devitrified or scummed up were CIM Peace, CIM French Blue, CIM Butter Pecan and some unknown ivory.

I can't find either Toilet Duck or Snobol here on Kauai so I tried another toilet bowl cleaner (extra strength with rust cleaner in it) and it didn't work after soaking overnight.

Thank you for everyone's advice. I don't know how to prevent this and I am not finding a solution to fix it, so I'm just gonna go sit in a corner and cry now. :(

squid
2011-10-23, 12:41pm
Prop the door open when annealing.

Lisi
2011-10-23, 1:48pm
CIM Olive. Other beads that were devitrified or scummed up were CIM Peace, CIM French Blue, CIM Butter Pecan and some unknown ivory.

I can't find either Toilet Duck or Snobol here on Kauai so I tried another toilet bowl cleaner (extra strength with rust cleaner in it) and it didn't work after soaking overnight.

Thank you for everyone's advice. I don't know how to prevent this and I am not finding a solution to fix it, so I'm just gonna go sit in a corner and cry now. :(

Oh wow, all those colors?? I'm so sorry! I was thinking it was a color or two that was doing this and we could narrow down the cause. Like squid says, prop the kiln door open and see if that gives you any improvement.

Could you look up other beadmakers in your area? Maybe they could batch anneal for you until the problem is worked out or when you get the new kiln. If your beads are small (less than 13-14mm), you're cooling them in a blanket, vermiculite, or the annealing bubbles and you don't mind shipping them to me, I could batch anneal them for you. I'll pay the return shipping. :)

Lyssa
2011-11-01, 1:42pm
Ok, I ran a batch last night with half batch annealing beads and half brand new beads hot off the torch. (Of course I ramped up to garage temp then started making the new beads.)

About half of the batch annealed beads got the icky scum around the bead hole and half did not. NONE of the new beads got the scum. So it's either something about the ramping up, OR as someone suggested it might be my mandrels. I'm going to run a test of batch annealing my beads on mandrels coated in bead release and see if 1) I can get 3/32" holed beads onto 1/16" mandrels with release on them and 2) if the release protects the beads. I'm thinking it will protect the beads. That would be a great solution right now, I'm looking forward to testing it tonight!

jaci
2011-11-01, 4:53pm
wait.. you are removing the extra bead release when batch annealing but leaving them on a mandrel? I suppose that the mandrels could be 'fuming' the beads.... Just take them off all together and pile them up in the kiln or dont clean the release off the rods. How fast are you ramping up?

Lisi
2011-11-01, 6:09pm
Did you mention that your mandrels were not stainless steel? Where did you get them?

Lyssa
2011-11-01, 6:24pm
Jaci: ramping up over 2 hours. I batch anneal with several beads on each mandrel, not one bead per mandrel still attached with bead release. I have hundreds of beads I need to batch anneal.

Lisi: yes, my mandrels are not stainless steel. I made them myself with piano/music wire from the hobby store. Much cheaper, and work FANTASTIC for making beads, but obviously not so much for batch annealing. Also, they rust like nobody's business if I don't dry them completely after cleaning. But that's Hawaii on rustable objects for you.

Lisi
2011-11-01, 10:03pm
Jaci: ramping up over 2 hours. I batch anneal with several beads on each mandrel, not one bead per mandrel still attached with bead release. I have hundreds of beads I need to batch anneal.

Lisi: yes, my mandrels are not stainless steel. I made them myself with piano/music wire from the hobby store. Much cheaper, and work FANTASTIC for making beads, but obviously not so much for batch annealing. Also, they rust like nobody's business if I don't dry them completely after cleaning. But that's Hawaii on rustable objects for you.

Oh my...then it's very likely this metal (alloy compound likely) is fuming into the atmosphere of your kiln. If you need mandrels you can get them from Howaco glass, by the piece and her shipping will be very reasonable.

I will bet you that's what it is!

Howaco
2011-11-01, 10:50pm
I would be very, very careful about not using stainless steel for your mandrels. Find out what your mandrels are made of and find out what type of fumes they can put off when they are getting to such a high temperature in your torch flame. I would be worried that you might be breathing in toxic fumes. I hope that is not the case, but please check into it.

DreamMuse
2011-11-01, 11:41pm
I don't mean to belabor my own experiences, but my dark lapis cobalt beads that got the same type reduction were batch annealed off the mandrel. I'm still wondering if my beads got devit due to a reduction atmosphere in my AIM.

Lyssa, I don't know if you ever mentioned if your kiln was the kind that closes tight?

jaci
2011-11-02, 7:14am
Jaci: ramping up over 2 hours. I batch anneal with several beads on each mandrel, not one bead per mandrel still attached with bead release. I have hundreds of beads I need to batch anneal.

Lisi: yes, my mandrels are not stainless steel. I made them myself with piano/music wire from the hobby store. Much cheaper, and work FANTASTIC for making beads, but obviously not so much for batch annealing. Also, they rust like nobody's business if I don't dry them completely after cleaning. But that's Hawaii on rustable objects for you.

Try a slower ramp, and just pile your beads in a terra-cotta flower pot tray. (a few bucks tops at any general surplus store, walmart etc*see picture below*) No mandrels You don't really need the mandrels at all. if you are removing the beads anyways, leave them off. I am betting that yes the metal you are using has some weird alloy in it and is the problem.

You can also cut your own mandrels for just a few bucks that are stainless steel. Go to a welding shop/ gas supply such as airgas/abco whatever you have in hawaii and ask for 316L stainless TIG welding rods. You can get them in any diameter you want. 1/16, 3/32, 5/64 5/32 whatever. Then you can cut them to the length you want. One end will be stamped, don't use that end!!!!! You will never get the bead off!!! LOL Just use a pair of bolt cutters or a cutter on a dremel or saw made to cut metal. I do this all the time. Just watch the top. You may want to grind it smooth. It can flare when you cut it and it may be difficult to get beads off if your release is on the thin side. Its still super easy to do with a dremel!!!!

My 3/32" 316 L cost me about $20 for a 1lb tube. I don't remember how much was in it, but I got a lot of mandrels out of it. They come in 36 inches pieces.

You can also use 308, 312, 314, whatever is similar. Explain to your welding guy that you need this or similar in stainless. They will hook you up!

http://t1.gstatic.com/images?q=tbn:ANd9GcT1L0d-aJuZyxaNboLf3XQJcnHwN6rtyW15YsK_E7XpIn14hqk8bAb1GL Y <<< the thing that is on the bottom under the flower pot. You can get them in so many sizes its easy to find one to fit your kiln.

Lyssa
2011-11-03, 12:14pm
Well, the terra cotta flower pot dish didn't work. All the colors that got icky in previous batches got icky in last night's batch. I have two more ideas to try, but now I've ruined about half of all the hundreds of beads I've made over the last 6 months and I have no more beads to batch anneal. I'm gonna make a handful of beads tonight then batch anneal them tomorrow changing yet another variable: there is a stainless steel metal plate in the bottom of the annealer that could be causing it. We'll see. Wish me luck.

Polgarra
2011-11-03, 12:24pm
Are you still using the devardi warmer as an kiln? Could that be part of the reason you are getting devit?

Lyssa
2011-11-03, 12:44pm
Yes and who knows.

If after my next two tests I'm still getting the ick I'm going to ask for a refund and put the money towards a kiln.

(I don't use the word "devit" anymore in this thread 'cause people insist that "devit" only happens in the flame, despite the actual definition of the word "devitrify". :) )

Are you still using the devardi warmer as an kiln? Could that be part of the reason you are getting devit?

Polgarra
2011-11-03, 12:56pm
Yes and who knows.

If after my next two tests I'm still getting the ick I'm going to ask for a refund and put the money towards a kiln.

(I don't use the word "devit" anymore in this thread 'cause people insist that "devit" only happens in the flame, despite the actual definition of the word "devitrify". :) )

I have no idea if the icky could be caused by the warmer but honestly I think it is something to seriously look at. Has anyone successfully used it to batch anneal? It seems like there should be a way to do it but maybe some of the materials are degassing or something similar. I don't believe it was designed to be an annealer so maybe there is some feature that has been overlooked that is making your beads icky.

I am so sorry that so many beads were ruined, that is just unbelievably frustrating.

Lyssa
2011-11-03, 1:04pm
The first three or four batches I annealed didn't get icky. That's the only way I know that it's (probably) not the annealer. And there just doesn't seem to be any reason for the annealer, an steel body with a glazed ceramic inner liner, to cause beads to lose their glassiness. Also, the beads I annealed straight out of the flame didn't get icky.

Anyway, I'm just grasping at straws here. I'll try my next two tests and see what happens.

I have no idea if the icky could be caused by the warmer but honestly I think it is something to seriously look at. Has anyone successfully used it to batch anneal? It seems like there should be a way to do it but maybe some of the materials are degassing or something similar. I don't believe it was designed to be an annealer so maybe there is some feature that has been overlooked that is making your beads icky.

I am so sorry that so many beads were ruined, that is just unbelievably frustrating.

Damselfly
2011-11-03, 1:08pm
but now I've ruined about half of all the hundreds of beads I've made over the last 6 months

That really sucks!

Maybe you should try etching the ruined beads and see if you can salvage them that way. I think you said you didn't like etched beads, but some people do, and it might at least be a good idea for the beads you can't sell otherwise.

Lyssa
2011-11-03, 1:12pm
Actually I do like etched beads, and if/when I've figured out what's causing the ick I will definitely give etching a try. Thank you for helping me remember there is a possibility of salvaging these beads. :)

That really sucks!

Maybe you should try etching the ruined beads and see if you can salvage them that way. I think you said you didn't like etched beads, but some people do, and it might at least be a good idea for the beads you can't sell otherwise.

jaci
2011-11-03, 1:42pm
I don't know what to say... this is weird.. and YES the metal plate could be causing it too. IT could be a combo of the beads you are annealing at the same time too. The beads could be fuming each other. If there are colors that are known to cause some 'divit'/reduction do them separately maybe? It may still be the mandrels even though they are not on the bead anymore when you batch anneal, or maybe just something in the annealer itself that is causing it. The only sure way to tell would be to get some beads batch annealed somewhere else in a kiln.

Howaco
2011-11-03, 1:48pm
The first three or four batches I annealed didn't get icky. That's the only way I know that it's (probably) not the annealer. And there just doesn't seem to be any reason for the annealer, an steel body with a glazed ceramic inner liner, to cause beads to lose their glassiness. Also, the beads I annealed straight out of the flame didn't get icky.

Anyway, I'm just grasping at straws here. I'll try my next two tests and see what happens.

I'm still going to guess it is your mandrels. The more they are getting used the more likely they are giving off fumes. Also, the ones that went straight to annealing would probably be ok, because the mandrels are coated with bead release.

Polgarra
2011-11-03, 1:55pm
Could the fuming have left 'fumes' in the warmer so that now it affects the beads every time it is hot?

elasia
2011-11-03, 2:01pm
(edit sorry, i was rambling when you posted Jamey Lynn) i think it's the mandrels also, this recently happened to me

I normally make my own mandrels, but cleaning out a drawer I recently found a pack of 12 I bought somewhere so I used them.
They are not stainless, I'm thinking steel? Wish I'd have looked at them closer before I used them. :rolleyes:
Anyways the beads made on these, they have this icky/devit to them. (annealed on mandrels)

Not all, only some. One for sure is CIM's Gelly, CIM Mojito (which got an odd milky haze)..so it's only some glass that was affected, oops i looked and one is dark ivory with some frit

I'm just going on a whim to say it's a metal in your mandrels as others mentioned, esp since it seems to be just the ends right? Sorry if I missed it but have you tried new stainless mandrels? Even if they are off in the kiln, maybe while in the torch some of the metals on your mandrels messed up the beads?

-later tonight i'll make quick beads with some of the glasses you mentioned on these odd mandrels i have and see if it happens again.

Lisi
2011-11-03, 4:35pm
Well, the terra cotta flower pot dish didn't work. All the colors that got icky in previous batches got icky in last night's batch. I have two more ideas to try, but now I've ruined about half of all the hundreds of beads I've made over the last 6 months and I have no more beads to batch anneal. I'm gonna make a handful of beads tonight then batch anneal them tomorrow changing yet another variable: there is a stainless steel metal plate in the bottom of the annealer that could be causing it. We'll see. Wish me luck.

Lyssa,

Gather up your next bunch when you get enough to want to send and I'll batch anneal them for you. :)

Lyssa
2011-11-03, 4:52pm
Thank you Lisi, I will do that. First I want to see if I can figure out what is WRONG with what I'm doing. This annealer should NOT be the culprit, there's just no reason for it, but if it is I want to narrow it down so I can honestly tell Devardi that the annealer didn't work right and I want my money back.

Lyssa,

Gather up your next bunch when you get enough to want to send and I'll batch anneal them for you. :)

Lyssa
2011-11-04, 12:46pm
Ok, I've decided the annealer has to go back, but guess what! Last night I ramped the beads up in the annealer and flashed them through the flame and they came out SHINY! (I put the beads into vermiculite to cool, not back into the annealer.)

So, after a ton of wasted effort, time and electricity, it looks like I'll be able to recover the beads I thought were completely ruined. Obviously, any beads that have raised decorations on them, like flowers will probably be messed up, but that's only about 1/4 of the beads and I can probably fix them a bit while I have them in the flame.

Lisi, when I get done with all of this "un-devitrifying" I'll be sending you the mother of all batches to anneal. I figure I can send these beads to BOC and/or give them for Christmas presents. :)

Thank you everyone for all your suggestions and advice. Time to start putting my pennies away to save up for a kiln.

jaci
2011-11-04, 4:48pm
Glasshive has a payment schedule that you can get into to save for your kiln. It's a great idea too to ask for kiln $ in lou of gifts for Christmas too.

Lisi
2011-11-04, 8:28pm
Okay, I will be ready! My kiln is 12" deep so there is plenty of room for all of those! I'll even clean the holes for you if they need it. :)

caogomi
2011-11-05, 1:15am
Some info on devit from Contemporary Lampworking (hope its ok Bandhu! lol)

"Devitrification - Crystallization of glass. Glass which is heated incompletely or unevenly during working can turn foggy looking and dull on the surface because the glass has begun to crystallize. Chemical impurities on the surface of the glass can also cause devitrification. It can often be remedied by remelting the surface of the affected area and exercising caution not to bend, twist or otherwise stress it until the glass cools completely. Sometimes sprinkling table salt (NaCl) on the hot glass can reverse devitrification."

So the reason some people are picky about you calling it devit is they are not entirely sure it is your glass crystallizing or if it is just mud or mucky color coming from the metals in the glass leeching out to the surface.

The reason this may be important is that if it isn't devit but metal fume then I imagine that there might be different fixes and steps involved in tracking down the source of the problem, let alone figuring out which is which to begin with. No reason to go down a path thinking its one thing and have none of the fixes for that help as it would only cause more frustration for ya I imagine ;D.

You may try making sure (if you have not already) that your glass is nice and clean before working with it, wipe it down or even try to wash a stick and leave another as is and see if they both result in the same problem. As this as stated above can be a cause.

More from CL:

"Soaking too long at the upper and lower ends of the annealing temp range can cause problems. In some glasses, oversoaking at the strain point or the softening point can cause devitrification."

Note that the following was discussing pyrex, don't know if it will work with other glass...

"...This frost surface can be reversed by using one of the following procedures. First fill a salt shaker with pure sea salt, ground frit, or sodium perborate. Using a bushy fire to heat up the piece of glassware, slowly sprinkle the contents of the shaker into the bushy flame, allowing the flame to carry the contents onto your hot glass piece. You will notice in a few moments that your devitrification will slowly but surely disappear."

That should be good for cold-worked or over worked cloudy glass that when put back in the flame doesn't seem to shine up. Though we are talking beads here, I had accidentally left a bunch of pieces in a kiln one time and came back to a slump, I caught them half way and killed the kilns temp, and by the time they were cool enough to come out they were nice and frosty with devit. Had to take out the pieces which were now thick slugs (still functional) instead of spoons. I didn't know this trick so I just used a nice oxy pin type flame to even them out. But I have had issues in the past of overworking straight cobalt 6 and would get frost sometimes on pieces with the color done on the outside of the glass. Never could get it to go to normal with heat. So I cannot wait to try the above method. I seem to remember something like vinegar or something else that was supposed to clean up muckyness (not devit) fairly easy and quick, but I am unsure as to what book or glass mag I read it in or what it was specifically. In regards to the sea salt as someone on another board mentioned: "dont over do it tho or you'll build up a flaky salty scaley surface.(also this process makes a huge mess if not properly prepared for it :P)"

elasia
2011-11-05, 11:44pm
^good info

Lisi can i send mine off to be cleaned also? :badgrin:
kind of you to help out though

Lyssa i'm sorry i haven't melted anymore on my 'bad mandrels' to see if it happens, i haven't been at the torch :/
but as said, since it's on the ends near the mandrels (or so i gather from the photo), and you're using piano wire, that's still suspect to me...oh and that it happened to me on those crap things someone sold me.
have you tried stainless steel mandrels at all?

Anne Londez
2011-11-06, 10:57am
I was going to write a diatribe about what devit exactly is but I'm glad someone else did :)

Just want to add that for some reason, the annealing temp that's going around as the correct one for Effetre and similar glasses of 960F is way higher than what the manufacturer give (478 C for Effetre, which is 892 F). This means that most annealing kilns are pre-programmed with annealing cycles that start way higher over the annealing temp, at a temp where I suspect the glass can be soft enough to be able to devitrify. I'm not saying that's what's happening to you but added to the fact that Devardis kilns don't seem to be the most accurate ones, there may be something in it.

I've made some softening experiments with Effetre rods to calibrate my big fusing kiln (which I use to anneal bigger pieces) and some of the colors start softening around 500-510C (932-950F).

Lyssa
2011-11-07, 2:28pm
Anne --

I'm a bit confused. All the advice I've gotten about batch annealing schedules says to ramp up to 950/960/970 F (what people say is the standard "garage" temp) and sit there for an hour or so, but then to ramp down and soak for an hour or so at 840/850/860 F. You say Effetre should be annealed at 892 F, does that mean one shouldn't go higher than 892 F?

I was going to write a diatribe about what devit exactly is but I'm glad someone else did :)

Just want to add that for some reason, the annealing temp that's going around as the correct one for Effetre and similar glasses of 960F is way higher than what the manufacturer give (478 C for Effetre, which is 892 F). This means that most annealing kilns are pre-programmed with annealing cycles that start way higher over the annealing temp, at a temp where I suspect the glass can be soft enough to be able to devitrify. I'm not saying that's what's happening to you but added to the fact that Devardis kilns don't seem to be the most accurate ones, there may be something in it.

I've made some softening experiments with Effetre rods to calibrate my big fusing kiln (which I use to anneal bigger pieces) and some of the colors start softening around 500-510C (932-950F).

Anne Londez
2011-11-08, 2:49am
Not necessarily but the annealing schedule will be different if you start at 960 F, which is the top of the annealing range, than if you start at 900 F, which is the bottom. I wish people would stop treating annealing as a kitchen recipe that everyone can spice to their own convenience. It is a sicentific process that has been very precisely documented. There isn't one specific annealing temp but a range and the annealing temp given by the manufacturer is the bottom point of that range. Where you start in that range affects the holding time and the ramping rates. I suggest Duhnam's Contemporary Lampworking as a first read. I'd suggest more specific lit but all I have is in French...

The 960 F schedule is the one that is recommended by Bullseye as optimal for their own glass. For some reason, when Americans started working with Effetre, they kept the schedule. However if you go to Murano, where they've been working with Effetre for quite some time, you'll find that they anneal around 900F. Why ? Because they know that Effetre starts softening around 960 F, which I think has a bearing in the case we are discussing here.

Lyssa
2011-11-08, 11:12am
That makes a lot of sense.

Now, I could go look this up, but I'm lazy. :) Isn't Bullseye a different COE than 104?

In my case, I'm batch annealing, and I've never understood why people say to go up to a hundred degrees OVER annealing temp of 104 then back down.

Not necessarily but the annealing schedule will be different if you start at 960 F, which is the top of the annealing range, than if you start at 900 F, which is the bottom. I wish people would stop treating annealing as a kitchen recipe that everyone can spice to their own convenience. It is a sicentific process that has been very precisely documented. There isn't one specific annealing temp but a range and the annealing temp given by the manufacturer is the bottom point of that range. Where you start in that range affects the holding time and the ramping rates. I suggest Duhnam's Contemporary Lampworking as a first read. I'd suggest more specific lit but all I have is in French...

The 960 F schedule is the one that is recommended by Bullseye as optimal for their own glass. For some reason, when Americans started working with Effetre, they kept the schedule. However if you go to Murano, where they've been working with Effetre for quite some time, you'll find that they anneal around 900F. Why ? Because they know that Effetre starts softening around 960 F, which I think has a bearing in the case we are discussing here.

PittsGlass
2011-11-08, 12:41pm
Anne, you are right on there. Even Bullseye is now updating their schedule to start at 920-900 range. They did a ten year study on finished work. Longer times at lower temps are their new mantra. I'll see if I can find the link to the bulletin.

Anne Londez
2011-11-09, 3:03am
Oops, I was quoting the annealing temp of Effetre from memory and I made a slight mistake. I checked the catalog yesterday and it's 470C, which is 870F... even lower than what I remembered !

And Aymee that is correct, Bullseye is 90 COE, which means that is is a stiffer glass.

Damselfly
2011-11-09, 9:16am
I knew that the "annealing" temp of Effetre is 870F - I have a step on my program that holds there for an hour - but you wouldn't want to garage at that temp, would you? I think the higher garaging temp was designed to allow you to open and close the kiln (which essentially crash cools it temporarily) without going underneath that strain point.

I have my garaging temp sent to 930, and I can easily get down to 890 if I have the door open and am arranging beads to fit more in. It seems to work for me....

Lyssa
2011-11-09, 11:28am
All the batch annealing schedules I've seen say to go up to the mid 900s, hold for an hour, then ramp down to the mid 800s, but I've always wondered why. What you say makes a lot of sense so maybe for people who are batch annealing, with no opening and closing of the kiln door, the first hold doesn't need to be in the 900s. Maybe you can go up to 870 and just hold there for an hour or two, depending on the size of your beads, and then ramp down past the strain point. It would cut down my batch annealing time by an hour, that's for sure. I wouldn't have to take that one hour to ramp down from the mid 900s to the mid 800s.

Does that sound right?

I knew that the "annealing" temp of Effetre is 870F - I have a step on my program that holds there for an hour - but you wouldn't want to garage at that temp, would you? I think the higher garaging temp was designed to allow you to open and close the kiln (which essentially crash cools it temporarily) without going underneath that strain point.

I have my garaging temp sent to 930, and I can easily get down to 890 if I have the door open and am arranging beads to fit more in. It seems to work for me....

Anne Londez
2011-11-09, 11:49am
It would cut down my batch annealing time by an hour, that's for sure. I wouldn't have to take that one hour to ramp down from the mid 900s to the mid 800s.

Does that sound right?


Yes and no... As mentioned above, annealing at a lower temp means that you need a longer holding time. Life's not simple ;)

Garaging temp depends on your kiln. I usually garage around 490C but then I have a well constructed kiln that doesn't easily lose temp when the door opens.

nklt0
2011-11-09, 4:48pm
Here's the Bullseye article on Annealing that Pam mentioned.
http://www.bullseyeglass.com/methods-ideas/recommended-annealing-cycle-for-bullseye-glass.html
Also have a read on their annealing time recommendation (Technotes 07)

Also, I believe this article explain why devit occurred if some effetri colour are softening at 960F. I think your problem with those CIM colours indicate that the softening temperature for them is slightly lower then most effetri (therefore, incompatibility issue that we hear some times).
http://www.bullseyeglass.com/images/stories/bullseye/PDF/TechNotes/technotes_04.pdf

As for annealing time, how big is your bead? If you make small beads (1/2 inch thick or less) 1 hour is enough especially if you anneal them suspended on a mandrel. However larger beads will need longer.

Lyssa
2011-11-09, 5:02pm
Only thing to reply to at this time:

Not on a HH, but I do make small beads. I just like 'em small. :)

Here's the Bullseye article on Annealing that Pam mentioned.
http://www.bullseyeglass.com/methods-ideas/recommended-annealing-cycle-for-bullseye-glass.html
Also have a read on their annealing time recommendation (Technotes 07)

Also, I believe this article explain why devit occurred if some effetri colour are softening at 960F. I think your problem with those CIM colours indicate that the softening temperature for them is slightly lower then most effetri (therefore, incompatibility issue that we hear some times).
http://www.bullseyeglass.com/images/stories/bullseye/PDF/TechNotes/technotes_04.pdf

As for annealing time, how big is your bead? If you are on HH and making small beads (1/2 inch thick or less) 1 hour is enough especially if you anneal them suspended on a mandrel. However larger beads will need longer.

nklt0
2011-11-09, 5:04pm
Only thing to reply to at this time:

Not on a HH, but I do make small beads. I just like 'em small. :)

Sorry, you are right. HH have no relevance on this subject. I was reading another thread and got mixed up. But size of the beads is important.

Lyssa
2011-11-09, 5:56pm
I took a look at them and I wanted to say thank you for the links. This really makes me want to figure out for myself what the best annealing schedule is. I feel the need to either go back to university and get a materials science degree or spend the next few years testing different annealing schedules with different glasses, combination of glasses, sizes of beads, etc.

Too many variables!!! LOL

Sorry, you are right. HH have no relevance on this subject. I was reading another thread and got mixed up. But size of the beads is important.

Anne Londez
2011-11-10, 3:28am
I took a look at them and I wanted to say thank you for the links. This really makes me want to figure out for myself what the best annealing schedule is. I feel the need to either go back to university and get a materials science degree or spend the next few years testing different annealing schedules with different glasses, combination of glasses, sizes of beads, etc.

Too many variables!!! LOL

True but there is one way to overcome that issue: try an annealing schedule that is overkill from the beginning. Annealing schedules are well documented for fusing and your pieces are not bigger than fused pieces so base your schedule on the one for a small fused piece of about the same thickness. Bullseye's info is very useful, it just needs to be adapted to the actual annealing temp of whatever glass you're working with.

There is somewhere on the net a program that was made by glass scientists to modelize the annealing curve of a piece of soft glass depending on its shape and size... unfortunately it's in French. It's a modelization that's fairly accurate for larger pieces in my experience and one interesting thing it shows is that for tiny pieces, there is a minimum annealing time that you can't go under. For Effetre, that's around 25 min per cm of thickness for a round bead (under 1 inch) at the lower end of the annealing range. And there is a minimum cooling rate between the annealing point and the stress point that you can't go under either, which is roughly 1F per min.

Lyssa
2011-11-10, 11:43am
Last night's annealing convinced me I need to get a digital controller. Not like I wasn't convinced before, but last night's batch actually lost some beads. First time for everything. :(

True but there is one way to overcome that issue: try an annealing schedule that is overkill from the beginning. Annealing schedules are well documented for fusing and your pieces are not bigger than fused pieces so base your schedule on the one for a small fused piece of about the same thickness. Bullseye's info is very useful, it just needs to be adapted to the actual annealing temp of whatever glass you're working with.

There is somewhere on the net a program that was made by glass scientists to modelize the annealing curve of a piece of soft glass depending on its shape and size... unfortunately it's in French. It's a modelization that's fairly accurate for larger pieces in my experience and one interesting thing it shows is that for tiny pieces, there is a minimum annealing time that you can't go under. For Effetre, that's around 25 min per cm of thickness for a round bead (under 1 inch) at the lower end of the annealing range. And there is a minimum cooling rate between the annealing point and the stress point that you can't go under either, which is roughly 1F per min.

LarryC
2011-11-10, 11:53am
Last night's annealing convinced me I need to get a digital controller. Not like I wasn't convinced before, but last night's batch actually lost some beads. First time for everything. :(

Good call. Not sure you can ever achieve a sufficiently smooth transition through the critical areas without one.

PittsGlass
2011-11-10, 12:23pm
I think what happens is that people want a conservative schedule that allows them to feel that they are getting the "most" annealing possible. They also want to cover a range of sizes in one program. Kilns, even with digital controllers have a swing in temp. Depending on the kiln it could swing up to 40 degrees in either direction, giving a range of almost 80 degrees. These hotter temps try to account for that in the programs.

Lisi
2011-11-11, 7:05am
Whoa...you mean all this time (nine years) I've been making beads and the annealing temp for Effetre is 900F or below??! This is the first I've ever heard of this! Also the first I've heard of Effetre softening at 960?? I guess I've been lucky because I anneal mine on the mandrels and they have never wonkified out of shape.

Lyssa, now you aren't the only one who is confused! Damn...back to more research. sigh...

Damselfly
2011-11-11, 10:59am
Lisi, as I understand it, I think what people meant by saying the annealing temp of Moretti is 870F, is that's the strain point at which all the molecules line up permanently. Depending on how much heat you lose when you open and close your kiln to add more beads, you wouldn't want to garage at that temp while you're working.

Lyssa
2011-11-11, 11:27am
Lisi, as I understand it, I think what people meant by saying the annealing temp of Moretti is 870F, is that's the strain point at which all the molecules line up permanently. Depending on how much heat you lose when you open and close your kiln to add more beads, you wouldn't want to garage at that temp while you're working.

And therefore, Damselfly, if you're batch annealing and not opening and closing the annealer constantly, you don't really need to spend any time soaking above the annealing temp. Is that correct?

Lyssa
2011-11-11, 11:28am
That's exactly my point, Lisi. There appear to be "too many stories" for me to be able to know which one is true.

Whoa...you mean all this time (nine years) I've been making beads and the annealing temp for Effetre is 900F or below??! This is the first I've ever heard of this! Also the first I've heard of Effetre softening at 960?? I guess I've been lucky because I anneal mine on the mandrels and they have never wonkified out of shape.

Lyssa, now you aren't the only one who is confused! Damn...back to more research. sigh...

Damselfly
2011-11-11, 12:04pm
And therefore, Damselfly, if you're batch annealing and not opening and closing the annealer constantly, you don't really need to spend any time soaking above the annealing temp. Is that correct?

I would say Not Exactly, for the following reason:

Once they're cool, the molecules are in a fixed arrangement. If you only go up to 870F (the temp at which they become fixed), then you're not really allowing them to change or to relieve any stress that might be there.

I think you want to go higher so the molecules are a little more elastic, and soak there long enough to affect the entire bead, then go down to 870F (and hold) so that the molecules can become fixed once again.

FWIW - I've done some reading, but I'm certainly no expert on this.

Anne Londez
2011-11-12, 11:32am
Lisi, as I understand it, I think what people meant by saying the annealing temp of Moretti is 870F, is that's the strain point at which all the molecules line up permanently. Depending on how much heat you lose when you open and close your kiln to add more beads, you wouldn't want to garage at that temp while you're working.

Sorry but no, it's the actual annealing temp that's given by the actual manufacturer. I can copy the Effetre catalog if you don't believe it. The strain point is way below that.

Anne Londez
2011-11-12, 11:44am
Well I actually have the Effetre catalog scanned on my computer so here is the relevant page together with a close-up.

PittsGlass
2011-11-12, 12:38pm
Damselfly is correct IMHO. The more stress that could be accumulated in the design or thickness, the longer it needs to have free molecules, and the slower it needs to cool through and past the strain point. I would never suggest "minimalist" annealing practices. If the atmosphere in the kiln is normal and the space is adequate it not likely that there will be ill side effects to annealing longer than required. Not enough time on the other hand can cost you work.

If you want to go with manufacturers numbers you are limiting yourself to only using Vetro with Vetro, Cim with Cim, ect. Once you begin using more than one glass manufacturer you need to be finding a happy medium between the companies suggestions. I could never be happy with one color palate. I use a schedule that can handle some varied coe's and viscosities.

Glass is not one COE or viscosity, no matter what any manufacturer says (note the +/- 1.5 in the above chart). The colors are created to be as close as possible to the magic number. If you use one color alone you can have an empirical scientific formula to stand on, otherwise you need to use some form of generalization.

There is also a comprimise between proper annealing and acheving certain color combinations. Striking colors may require longer or shorter periods of annealing to get the desired effect. The science of annealing and the art of color can sometimes be at odds. It really depends on your end goal.

Simply stated, it is not likely to reach an exacting answer on the one perfect anneal schedule.

Lyssa
2011-11-29, 5:47pm
Turns out the "ick" really has nothing to do with the Devardi Mini Bead Annealer. I had a friend (CheriB) anneal a bunch of my beads for me and all the "problem colors" that were previously coming out "icky" in the Annealer came out "icky" in Cheryl's kiln.

*groan*

Lisi
2011-11-29, 6:09pm
Turns out the "ick" really has nothing to do with the Devardi Mini Bead Annealer. I had a friend (CheriB) anneal a bunch of my beads for me and all the "problem colors" that were previously coming out "icky" in the Annealer came out "icky" in Cheryl's kiln.

*groan*

Oh no! Are you on a HH and using propane and not MAPP or bulk propylene?? Please tell me that's it because if it is, then your problem can be solved by changing to bulk propylene or another similar to MAPP fuel. Propane can ick up glass, that's the truth.

Lyssa
2011-11-29, 6:21pm
Nope, I'm on a Minor with Devilbiss 515 oxycon.

Lisi
2011-11-30, 6:53am
Nope, I'm on a Minor with Devilbiss 515 oxycon.

Okay, now...this is weird! Now I'm wondering about your flame chemistry. Do your candles have yellow or blue tips?

Damselfly
2011-11-30, 11:46am
If they looked fine after being torched, but got devit after being batch annealed, it would have to have something to do with the annealing, wouldn't it? And since that explanation of annealing said it had to do with the glass crystallizing, I'm thinking that some glass is more prone to that when being reheated to less than molten state.

Whether it's due to how fast it ramps up, or just the temperature to which it ramps up, you may be out of luck trying to batch anneal those colors. I'm sorry you're going through this.

Lyssa
2011-11-30, 12:13pm
Yellow tips.

What would it mean if I had blue tips?

Okay, now...this is weird! Now I'm wondering about your flame chemistry. Do your candles have yellow or blue tips?

jaci
2011-11-30, 2:08pm
Yellow tips mean you are working in more of a reduction flame. Blue would be more neutral. This could be causing your problem. Your torch head may need some cleaning.

Lyssa
2011-11-30, 3:20pm
I always heard that you wanted blue candles with tiny yellow tips. Now I'm confused.

squid
2011-11-30, 3:56pm
You do want blue candles with tiny yellow tips.

Lyssa
2011-11-30, 4:10pm
Help! Contradicting advice! :)

Lisi
2011-12-01, 3:22pm
I always work in a slightly more oxygenating flame. So I dial out the yellow in the tips so I get just blue, but not to the point where the torch is hissing.

jaci
2011-12-08, 6:19am
Yea. I find myself working in more of a slight hiss... And you may need to adjust your psi on your propane. I have mine set between 8-10. And work on a oxy con around 4.5-5Lon. Idk what the psi is. (and of course adjust at the torch there after)

Lyssa
2011-12-09, 11:47am
I just discovered this thread (http://www.lampworketc.com/forums/showthread.php?p=3052478)which describes the exact problem I've been having, minus any mention of the ick showing up next to the bead holes.

jaci
2011-12-15, 6:50am
Maybe you two should chat about the torch kiln etc and see what is common between you to narrow down a solution.

Lyssa
2011-12-15, 6:53am
Yup, sent her a PM. :)