Flame annealing to prevent cracks? help a newb!

[badseed1]

So I have a few questions. But let me explain my situtation first. Got my hothead a few weeks ago, just got my glass and a few basic tools yesterday in the mail from sundance glass (which i just read a post that shows sundance to be unfavorable, anyone know why?). So all I have is a graphite marving pad, some needle nose pliers, and instead of vermiculite I went with fiber pads (I dont see anyone ever talking about them, mostly vermiculite, whats the reason for this? Are fiber pads less then satisfactory?) I do NOT have a kiln or plan on affording one any time soon... There you go, thats what i have to work with, that being said here is my main question. Since i dont have mandrels, i've been attempting teardrop pendants, they seem simple enough form the tutorials i've seen. I've attempted about 10 so far, getting a better shape each time, but more cracks! I am perfectly aware of the fact that the glass needs to cool evenly, but not quite sure what I need to do to accomplish that. Half of them come out fine, half come out cracked. Here is the URL of the tut I've been following http://www.youtube.com/watch?v=etwzrIMAaMw
I got down the stringer in a few tries. It's not until I make the "loop" and try and remove the punty (sp?) that the bead usually cracks (I can't see it but I can feel it.) Once it happened as soon as I touched the bead with my pliers, after that I started warming the pliers first (Is that a step in the right direction?) Some of them must crack while between the fiber blankets cause I don't always feel it. I wish I had a way to upload a picture. It seems that if I try and slowly cool the finished bead in the flame, the loop melts/warps. Anyone know of a more in depth video tutorial for simple pendants? Or just some helpful info/tips on how I can stop the cracking. And lastly, after I get this down, can anyone tell me of any other bead types I can produce with my limited amount of equipment? Thanks for helping out the newb!

-Ryno (badseed1)

[likes to make glass stuff]

OK, main problem:

That video is using boro, you are using soft glass. Boro is WAY more forgiving of thermal shock than soft glass. You can't do the kind of thing you want to do with boro on a HH. You can melt it. You can make things with it. It will take forever, and you just can't make mushroom pendants with boro on a HH.

Second big problem:

It takes time to learn to make beads that are round or donut shaped that don't thermal crack when you don't have a kiln. It's normal. Pendants are a step or ten harder than round or donut shaped beads. I'm sure it's possible to make them that survive and batch anneal with soft glass...but I wouldn't try it.

Mandrels: local welding shop. 316L rod, I'm pretty sure. Cheap. Less than $10 should get you mandrels. A bunch of mandrels. I'd get 3/32nd to learn on-you're less likely to bend them.

I don't think you're going to be able to do what you want to without a kiln, with soft glass. I'm trying this kind of thing with boro and screwing up my loops left and right, lol. I'm batch annealling them, but with boro it's not such a huge thing when you are learning.

Please make sure you've got adequate eye protection and ventilation, too, ok?

[badseed1]

That video is of a hothead I'm pretty sure (correct me if I'm wrong <--- newb) but it says so in the comments, and looks the same as mine. So I'm guessing he is using soft glass if that is the truth. I just (about an hour ago) finally made my first mushroom pendant. PERFECTION! *Bows and waits for applause. No cracks, perfect cap. It's nice, I'm guessing there is probably some stress though, and it may be fragile.

Thanks for the tip on mandrels, didn't want to make another $50 min. purchase just cause I forgot them in the last order.

What is batch annealing? Using a kiln I'm guessing?

As for eye protection, I am just using a dark pair of shades ATM, how bad is that? Ventilation is cool though. I knew it needed to be ventilated, but why is that exactly?

Thanks for the tips LTMGS. I'd still like to know more about flame annealing if anyone can point me in the right direction Even though my last piece turned out perfect (lol, translation: it's not cracked..)

[sosoft]

Originally Posted by badseed1

That video is of a hothead I'm pretty sure (correct me if I'm wrong <--- newb) but it says so in the comments, and looks the same as mine. So I'm guessing he is using soft glass if that is the truth. I just (about an hour ago) finally made my first mushroom pendant. PERFECTION! *Bows and waits for applause. No cracks, perfect cap. It's nice, I'm guessing there is probably some stress though, and it may be fragile.

Thanks for the tip on mandrels, didn't want to make another $50 min. purchase just cause I forgot them in the last order.

What is batch annealing? Using a kiln I'm guessing?

As for eye protection, I am just using a dark pair of shades ATM, how bad is that? Ventilation is cool though. I knew it needed to be ventilated, but why is that exactly?

Thanks for the tips LTMGS. I'd still like to know more about flame annealing if anyone can point me in the right direction Even though my last piece turned out perfect (lol, translation: it's not cracked..)

Seed,
What you are attempting is done all the time! Boro is easier to sculpt in the torch because it does not thermal shock as much as soft glass (remember that you can take that pyrex dish from the freezer and heat your food in an oven!)
Sculpting with soft glass has been done much longer than sculpting in boro. The Italians make a huge amount of $$$ or euros making figures from soft glass that are never annealed.
You will have to practice working a figure or object from one end to the other. You can use a soft glass rod to built your piece from. Like when making a small human form, starting with the lower body and then building a torso, head, arms, etc.
The technique involves finishing an area and allowing it to cool as you work on another area.
You can never come back and RE-HEAT the completed area. It will crack, but when you are done the piece does not need to be protected in any way when it cools.
Study books on the subject to learn about heat control when sculpting. It's not that hard if you see it done and then practice. There are a few teachers who can show you as well. I do not know if there are videos on sculpting soft glass, but if you watch boro videos you can get the idea of how to shape. You can then plan your soft glass piece as a continuous process of building without re heating any of the completed sections.
Soft glass sculpting is fairly advanced heat control, but I have watched several students do it who have never even seen a torch!
The important thing is to try, you will learn eventually, even if you crack the first 50 pieces.
Have fun, remember there are no rules in art!
HITK,
Kurt

[Wonker]

Seed,

I don't think that the torch that guy is using is a hothead and it really does look like he's using boro to make that little mushroom. Like the others have said, working in boro is a lot more forgiving in terms of working a piece in and out of the flame without the thermal shock. If you're getting about half of them done using soft glass, you're really doing well, I'd say. The only thing I think that any of us could really say that might help is, if you're working soft glass, don't go very long without putting some heat back into the entire piece. In order to keep the thermal shock from cracking your piece, you're going to have to be ever mindful of the fact that if the piece cools too much you're going to lose it. When you punty up to the bottom, when you go back in to clean up the punty mark, your're going to get a crack if you've spent too long on the loop side without going back in to and heating the punty side . You have to have that internal clock going all of the time..and experience will teach you how to set that egg timer.

Good luck, and welcome to the addiction.

[sosoft]

Generally a soft bushy flame like a hot head can help you to work soft glass. You just need to find out what part of the flame you want, so that your heat will be right for what you are doing. Although I have not seen the boro tut referred to above, I make mushrooms all the time in soft glass, both in marbles and pendents. Depending on the thickness of the piece, re heating may be appropriate. When making small pieces you can use the heat applied, heat denied tech I first shared about.
If you get a mandrel for bead work, than by all means use it without release to hold your work as you are making it ( a punty). All of the soft glass furnace workers use stainless steel for puntys. Put the mandrel into the flame until it glows orange, just the tip (1/8 inch) then press it lightly into whatever soft glass gather you are trying to hold. It will stick very well, in fact if you make a bead without release, the only way you can remove the glass from the mandrel is with a hammer.
Remember to keep the joint warm now and then, don't sweat it, but flash the glass-steel joint now and then.
For a better description of this process and some of the best ideas on how to work soft glass, I would recommend you buying the book about marble making by Drew Fritts. Just google his name and look at his web site.
The chapters on ventilation and color mixing alone are more than worth the price of $30.
If you learn how to control the heat in the glass, you will be able to make anything you desire
HITK,
Kurt

[BugNerd]

The video is a hothead, looks just like mine, and he says at some point that he is working farther out because he's on propane ONLY and doesn't want to scum the glass.

[Cosmo]

That's a hot head alright. And no way that's borosilicate. You can't get borosilicate that hot on just propane.

[jamie lynne]

that is certainly a hot head. and that is certainly soft glass.

the bigger the better for learning, try 14-15 mm clear and a larger version of the mushroom. i made many on my hothead no problem for 3 years before i got my minor. also after i break off my punty and i'm holding it with my pliers i gently run it back and forth thru the flame again, not enough for it to get red hot again, just evening out the heat a bit. it helps with thermal cracks.
i made large pendants for 3 years on my hot head and cooled in a fiber blanket, didn't kiln anneal, cause i didn't have the $$, and all of them are still alive and well. that being said i never sold any back then, but i did give them away, i don't feel right selling stuff that is not annealed.

the yellow daisy in my profile picture album is made on a hothead, and soft glass. it wasn't annealed for a year. but when i got my kiln i batched it.

[likes to make glass stuff]

Originally Posted by badseed1

That video is of a hothead I'm pretty sure (correct me if I'm wrong <--- newb) but it says so in the comments, and looks the same as mine. So I'm guessing he is using soft glass if that is the truth. I just (about an hour ago) finally made my first mushroom pendant. PERFECTION! *Bows and waits for applause. No cracks, perfect cap. It's nice, I'm guessing there is probably some stress though, and it may be fragile.

Thanks for the tip on mandrels, didn't want to make another $50 min. purchase just cause I forgot them in the last order.

What is batch annealing? Using a kiln I'm guessing?

As for eye protection, I am just using a dark pair of shades ATM, how bad is that? Ventilation is cool though. I knew it needed to be ventilated, but why is that exactly?

Thanks for the tips LTMGS. I'd still like to know more about flame annealing if anyone can point me in the right direction Even though my last piece turned out perfect (lol, translation: it's not cracked..)

I'm still disagreeing that he's using a HH and soft glass. If the experienced folks will listen to the video, several times he talks about speeding it up (double time, that kind of thing). Personally, if I get soft glass that hot, it drips. Or boils. The amount of time he's waiting before re-introducing things into the flame, too, would guarantee shattering, I think.

He says he's using black for that stringer, too. You don't use black stringer really often with soft glass, because it's a transparent and turns purple, green, or blue when pulled down.

As for the comments-what I saw said something about it being nice to see a glass video that wasn't making beads on a HH. The comment was by someone else. It could be read as "Yay, someone's doing something different with glass in a video!" just as easily as "he's using a HH and not making beads".

I'm guessing he was using some sort of welding torch, since in later videos, he's got a regular torch. and talks about buying a glass type of torch. There are propane only torches out there.

he also mentions color in a way that boro folks do, not soft glass folks.

That aside, if you've got a HH aimed the way that torch is, you've got it going the wrong way. Aim it AWAY from your face. Very, very important.

Batch annealling- When you make things and save them until they can be annealed in a torch. It's not OK to sell items that haven't been annealed in a kiln, and you cannot anneal in a torch. Period. Annealing is slow cooling, and it's just not possible to do that in a flame adequately. There are folks around who will batch anneal your items for you, either by you mailing them, or by finding someone local to you.

Eye protection. You really need safety glasses at a bare minimum. Read up on the various types of eye protection. Some cuts the flare one sees in with the torch flame, though your sunglasses may do that. I'm betting they don't give full eye protection, though, and having had rods spit bits at me and bounce off my eyebrows when I wasn't wearing full style frames, I'd highly recommend that kind. You can get cheap clear safety glasses for very little at that welding supply shop you are getting your mandrels at. If you intend to do this for any length of time, you've got to read up on appropriate eye protection.

Ventilation: You are burning propane or another fuel to melt the glass. That alone creates by products that shouldn't be trapped in the room with you. You've got to get those fumes (and the fumes from whatever else you are working with) outside, and fresh air into the room you are in.

Check the safety forum for more info on the eye wear and ventilation things-lots of good info there.

And if you're managing those with soft glass, so new to it all, awesome!

[badseed1]

Thanks all, been a big help.

[Elizabeth Beads]

I have nothing but good things to say about Sundance. And their mandrels by the lb. are a great deal if you don't want to mess with cutting and deburring your own. You'll need bead release too. Annealing bubbles in a hot crockpot (or empty coffee can on a hot plate) would be better than fiber blanket for cooling and is not very $$$. (I did not watch the video, so no comments on the torch or glass). Good luck!

[Diane (clarus)]

That is definitely a Hot Head in the video. I recognize the torch and the flame.

Sundance is where I got my first kit, when they were still in Mountain View. I have ordered from them since they moved to Paradise and have nothing but good things to say about them.

Much of beadmaking, whether on or off-mandrel, is about heat control. Perhaps you are letting the glass get too cool outside the flame? Soft glass is very senstitive to thermal shock if parts of it aren't within a range and then yes, it will crack. This kind of thing can only be learned by experience.

One tip I learned early on from reading a post from Val Cox is to just spend time melting glass in the flame to see how different glasses melt. Transparents are stiffer than opaques, and even then they vary by color. I'd suggest also getting some books and videos. Many of the books are available at public libraries, and sometimes you can find them in used bookstores or on eBay. Or here in the Garage Sale. The videos can be rented through www.smartflix.com for a nominal fee. Start with the set from Jim Smircich - he is the master of heat control.

As others have said, you will need didymium safety glasses so you don't burn your eyes out from the solar flare in the flame, and have some kind of ventilation that is blowing the fumes away from you. There's a ton of info in the Safety section, and a good website to get info on this specific topic is http://mikeaurelius.wordpress.com/ .

Most of all, have fun!

-Diane

[jamie lynne]

i don't think it is pointing at him, if it was.... i think he might need a trip to the ER .... i think it looks that way because of where the video cuts it off, and i didn't hear any lingo in that video that isn't used by soft glass users, and yes black does thin out (turn purple) when pulled thin, but that doesn't mean you can't use it as a stringer. here is a pic of my very tired, retired, hothead to show that it is INDEED a hot head he is using. not trying to start a fight but....

[prairieson]

Originally Posted by sosoft

Seed,
...Boro is easier to sculpt in the torch because it does not thermal shock as much as soft glass (remember that you can take that pyrex dish from the freezer and heat your food in an oven!)...
Kurt

Just a quick note... Pyrex cookware hasn't been boro for quite a few years, it's tempered soft glass.

[Dale M.]

Torch is definitely Hot Head.... Look at the flame "shape"... It has the typical small candles on out side and one large candle in center....

Dale

[badseed1]

Originally Posted by jamie lynne

the bigger the better for learning, try 14-15 mm clear and a larger version of the mushroom. i made many on my hothead no problem for 3 years before i got my minor.

I have some 15mm rod, it's supposed to be soft glass but it seems like it takes half an hour to get a good gather. I'm putting flame on it the whole time, it doesn't want to drip at all. Is it that my HH isn't hot enough?

[likes to make glass stuff]

I'd say not for that diameter rod.

(I used a HH for several years. 8mm was about my max)

[Lorraine Chandler]

#1. I like Sundance.

#2. It is a HH torch being used in video.

#3. Fiber blankies, vermiculite and erroneously named "annealing bubbles" are only holding mediums until you can get your beads to a kiln to anneal them. In a kiln slowly ramped down through the stress zones for that particular coe of glass is the only way to safely and properly anneal.

If you are going to be a lampworker be prepared to spend lots of money as this hobby is very very expensive.

#4. Even though you make a bead and it does not crack, consider yourself lucky because the stress fractures in that bead are there and probably lots of them. They are just waiting for a little bump or hit. Sometimes you will just find them laying there in the drawer cracked in half...hours, days, weeks, months or years later.

#5. It is totally frowned upon to make beads without annealing with the intention of selling them.

It's fine for now for practicing but do not sell anything that has not been kiln annealed. It is just very bad form. ( not that you are) just saying.....

Several people on this forum ship their beads out for batch annealing for a fee from another lampworker who is willing to anneal for them.

And last but not least you are trying to run before you walk as far the beads you are trying to make. There is nothing wrong with trying to do more difficult beads at first but you will find it ...difficult. It is also a good idea to take a class. There is nothing like watching someone torch in person..You will have so many AHA!!! moments.

#6 The last and most important thing you need to know is that ventilation is a must have especially with a HH which is a terrible fuel burning dragon..Not efficient at all and the fumes are there, kinda like standing and working behind a car exhaust with the engine running....

All that aside..... Welcome to our world and good luck, be safe, have fun and check out the threads on how to make a mailbox annealer. It's cheaper and easier than you think.

Lorraine

[rg9403]

definitely a HotHead torch. Def. soft glass.

def. not an easy tech for a complete newb to jump into.

[jamie lynne]

yeah, i guess i used my 14-15 for actual dot implosions, for which more surface area is required / desired. but with some patience and practice i'm sure you can drip a 14 mm rod for mushroom pendants, if i can implode with it.... remember it just needs to get soft... he made his gather larger than his rod but it was only soft when he pushed the shroom.

be prepared to burn a few in the process. and remember you can put your own spin on these things too!

[sosoft]

Originally Posted by prairieson

Just a quick note... Pyrex cookware hasn't been boro for quite a few years, it's tempered soft glass.

Okay, I guess that could be some of the wild scuttlebutt on the internet, but:
Pyrex is a trade name for boro that is produced by Corning. They were one of the first companies in this country to make boro glass and still produce tons of it for use in lab glassware.
Baking dishes with the Pyrex logo are hard glass, period. You can't have a measuring cup that will take boiling water in soft glass of any kind.
Tempering of glass is normally done to glass in the 80's coe range of soft glass. The lower end of the range, but still considered soft glass. Most bottles and window glass are like this. Very stiff as it cools, good for machine forming.
Tempering is actually bad annealing, formed sheet glass (car windows, shower doors , office glass doors and the like) are heated evenly after it is made, but cooled too fast. The schedule is created to set up even tension in the glass so that when it is broken it shatters, like a prince rupert drop. It breaks into thousands of small pieces and falls to the ground like coarse fritt. This is all done so that when a human breaks a thick door pane, or you go thru the car window, you will not be sliced to ribbons by big shards left hanging in the frame. We use it in the film business all the time. When the actor throws the stunt man into the tempered window an effects person sets off a small charge that drives a steel spike into the corner of the window. The window shatters at the same time the stunt man goes through it. In the next cut he is laying on the ground with a special clear silicone glass substitute around him. No one gets hurt!
Tempering is also used in industry for a variety of reasons, but would be useless for cookware, if your tempered glass coffee pot was ever used on a stove the heat would release some of the tension in one area. The difference would break the vessel upon the next heat/cool cycle.
JMHO,
HITK,
Kurt
Ps We also use candy glass, which is made of clear resin. It will break easily on impact, but you can still get cut by the sharp shards. Tempered glass breaking looks better, but is way more expensive and harder to re-set if the shot goes south.

[sosoft]

[quote=2 TOUCANS;2536401][b][color="Olive"]#1. I like Sundance.

#5. It is totally frowned upon to make beads without annealing with the intention of selling them.

Wow,
I have never been totally frowned upon,what's the penalty for that?
Can't we let beginner find out accurate information for themselves, they will have a lot more fun. Art is freedom, being told what to do is not much fun.
Keep it real and hot!
HITK,
Kurt
Ps. I guess the Europeans who have made glass beads for maybe 200 years are not very smart, but if I could make the money they do by selling un annealed glass beads all over the planet, I guess I could live with a few frowns.
Oh, the commercial marble makers would also have to be included in that group. They have probably made the un annealed mistake about a billion times. And they sell to children!

[likes to make glass stuff]

Originally Posted by sosoft

Okay, I guess that could be some of the wild scuttlebutt on the internet, but:
Pyrex is a trade name for boro that is produced by Corning. They were one of the first companies in this country to make boro glass and still produce tons of it for use in lab glassware.
Baking dishes with the Pyrex logo are hard glass, period. You can't have a measuring cup that will take boiling water in soft glass of any kind.
Tempering of glass is normally done to glass in the 80's coe range of soft glass. The lower end of the range, but still considered soft glass. Most bottles and window glass are like this. Very stiff as it cools, good for machine forming.
Tempering is actually bad annealing, formed sheet glass (car windows, shower doors , office glass doors and the like) are heated evenly after it is made, but cooled too fast. The schedule is created to set up even tension in the glass so that when it is broken it shatters, like a prince rupert drop. It breaks into thousands of small pieces and falls to the ground like coarse fritt. This is all done so that when a human breaks a thick door pane, or you go thru the car window, you will not be sliced to ribbons by big shards left hanging in the frame. We use it in the film business all the time. When the actor throws the stunt man into the tempered window an effects person sets off a small charge that drives a steel spike into the corner of the window. The window shatters at the same time the stunt man goes through it. In the next cut he is laying on the ground with a special clear silicone glass substitute around him. No one gets hurt!
Tempering is also used in industry for a variety of reasons, but would be useless for cookware, if your tempered glass coffee pot was ever used on a stove the heat would release some of the tension in one area. The difference would break the vessel upon the next heat/cool cycle.
JMHO,
HITK,
Kurt
Ps We also use candy glass, which is made of clear resin. It will break easily on impact, but you can still get cut by the sharp shards. Tempered glass breaking looks better, but is way more expensive and harder to re-set if the shot goes south.

Kurt-

From the horse's mouth http://www.pyrexware.com/thetruthaboutpyrex/manu.htm

"Glass Material
PYREX® glass products are made using a tempered soda lime glass composite, as is the vast majority of consumer glass bakeware in the North American marketplace. The Cookware Manufacturers Association considers soda lime an appropriate material for glass bakeware."

[BeadMaven]

I agree with Lorraine / Toucans and I think she is right If you are going to sell, the beads should be annealed.

[jamie lynne]

yep they should be annealed, and remember they can be batched if need be, but it is better to throw a hot bead into a hot kiln, or atleast that is what i've been told. LOL

[Lorraine Chandler]

Sosoft...you are new here according to your join date and posts. If you stick around ( and I hope you do ) you will learn that not annealing beads for resale is FROWNED UPON!!!

Lampworkers have stepped into the 21st century and we have ways to know about stress in glass now that prove annealing beads is the right thing to do.

The following paragraph below from you contains inaccurate information on several subjects..

Lorraine


''''quote""" Ps. I guess the Europeans who have made glass beads for maybe 200 years are not very smart, but if I could make the money they do by selling un annealed glass beads all over the planet, I guess I could live with a few frowns.
Oh, the commercial marble makers would also have to be included in that group. They have probably made the un annealed mistake about a billion times. And they sell to children!end """"quote"""

[NMLinda]

Don't know where you get your information about Europeans not annealing their glass beads, Kurt. Also, not annealing beads, as Lorraine says, frowned upon because it is rude and unethical to customers. It increases the likelihood that something they paid their hard-earned money to buy will break during the time they own the piece. There's no reason to abuse customers in the name of so-called artistic freedom. It's so easy - and so ethical - to anneal beads so that customers can enjoy the purchase of an item that should stay stable virtually forever, that it begs the question why any honest person wouldn't anneal as a matter of course.

badseed1 - Mike's blog has a lot of excellent info, how to build adequate ventilation being one of them. Of all of your investments, ventilation and eyewear are the two areas you must never skimp on if you want to enjoy this additiction in long and good health. You only have one set of lungs and one set of eyes, so please cherish them. Mike's blog has great info on eyewear, also. There is further great info in the safety threads on this and similar forums. Finally, please read the safety section in James Kervin's book "More than you ever wanted to know about glass beadmaking" and in Bandhu Scott Dunham's book "Contemporary Lampworking". These are some of the best compendiums of lampworking safety I've seen out there in book form, and are excellent books, in general.

Lorraine is right about the hazards of the combustion products produced by any torch. Although not as toxic, you no more want to breath them than the exhaust of your car. There have been some chilling threads posted by folks who were not careful about critical safety items such as ventilation and suffered terribly as a result. One young man actually expired because he didn't take it seriously enough. By no means do I want to scare you off - safe ventilation is relatively straightforward to set up, as you'll see in Mike's blog and in some of the better posts here on LE and other forums. The danger is in doing nothing at all, or doing more toxic things like fuming without the right infrastructure.

The reason you need eyewear especially designed for hot glass is because any object heated to the temperatures used to melt glass will give off a black-body radiation signature in addition to the sodium flare most predominantly seen in the visible range. As part of the black body radiation phenomenon of hot items like melting glass, UV and IR is released at energy levels that can cause long term/cumulative eye damage, such as cataracts (please see James' book for a more comprehensive description). You need glasses, first, to protect yourself against flying glass bits (heat your glass too fast and it will pop....). Secondly, while plain safety glasses will attenuate most of the UV produced, ONLY eyewear specifically designed to filter out Infra Red will protect you from those harmful rays. Many folks either forget or are unaware that IR is as bad or worse than UV. Didymiums or better are necessary to protect your eyes from these harmful rays. Finally, some of the heavily silvered glasses can also produce light in the visible range sufficiently bright enough to be of concern. There have been some NIOSH reports published on visible light hazards as well as the hazards of both UV and IR.

Welcome to the obsession! It's engrossing, but not a casual or inexpensive addiction. Torch happily, but most of all, do your research and torch safe!

Linda

[sosoft]

Originally Posted by likes to make glass stuff

Kurt-

From the horse's mouth http://www.pyrexware.com/thetruthaboutpyrex/manu.htm

"Glass Material
PYREX® glass products are made using a tempered soda lime glass composite, as is the vast majority of consumer glass bakeware in the North American marketplace. The Cookware Manufacturers Association considers soda lime an appropriate material for glass bakeware."

Well, I have to apologize. I did not know that Corning sold the Pyrex name to World Kitchens in 1998.

"Pyrex is a brand name for glassware, introduced by Corning Incorporated in 1915. Originally, Pyrex was made from thermal shock resistant borosilicate glass. In 1998, Corning sold its consumer products division which subsequently adopted the name World Kitchen. Pyrex kitchen glassware, that is manufactured and licensed for sale in the United States, is now made of tempered soda lime glass at the World Kitchen facility in Charleroi, Pennsylvania[1], except in the European Union, where it is still made of borosilicate glass in France.[2] Pyrex laboratory glassware is also still made of borosilicate glass.[3]"

Pyrex meant Boro for 83 years and the name Pyrex in cookware has only meant soda lime glass for the last 11 years.
All of the Pyrex cookware I own is made of boro. It lasts a long time.
The choice of the word tempering for annealing is not really correct. Tempering is done after forming, but is not the same as annealing. It serves a different purpose. I suggest the information about present day Pyrex cookware was just ad copy meant to convey the durability of the line.
I agree that proper annealing of thick soda lime glass will produce a very shock resistant piece, but annealed lead crystal will withstand a ton of thermal shock. Put it into a dishwasher and it will actually start to melt away.
The point is that COE, compatibility and thermal shock in glass are very subjective. I am sure that you know of glass pieces made hundreds of years ago, never annealed, yet still stand as a testament to this mystery of glass.
Sorry for the wrong information,
HITK,
Kurt

[sosoft]

Originally Posted by NMLinda

Don't know where you get your information about Europeans not annealing their glass beads, Kurt. Also, not annealing beads, as Lorraine says, frowned upon because it is rude and unethical to customers. It increases the likelihood that something they paid their hard-earned money to buy will break during the time they own the piece. There's no reason to abuse customers in the name of so-called artistic freedom. It's so easy - and so ethical - to anneal beads so that customers can enjoy the purchase of an item that should stay stable virtually forever, that it begs the question why any honest person wouldn't anneal as a matter of course.

badseed1 - Mike's blog has a lot of excellent info, how to build adequate ventilation being one of them. Of all of your investments, ventilation and eyewear are the two areas you must never skimp on if you want to enjoy this additiction in long and good health. You only have one set of lungs and one set of eyes, so please cherish them. Mike's blog has great info on eyewear, also. There is further great info in the safety threads on this and similar forums. Finally, please read the safety section in James Kervin's book "More than you ever wanted to know about glass beadmaking" and in Bandhu Scott Dunham's book "Contemporary Lampworking". These are some of the best compendiums of lampworking safety I've seen out there in book form, and are excellent books, in general.

Lorraine is right about the hazards of the combustion products produced by any torch. Although not as toxic, you no more want to breath them than the exhaust of your car. There have been some chilling threads posted by folks who were not careful about critical safety items such as ventilation and suffered terribly as a result. One young man actually expired because he didn't take it seriously enough. By no means do I want to scare you off - safe ventilation is relatively straightforward to set up, as you'll see in Mike's blog and in some of the better posts here on LE and other forums. The danger is in doing nothing at all, or doing more toxic things like fuming without the right infrastructure.

The reason you need eyewear especially designed for hot glass is because any object heated to the temperatures used to melt glass will give off a black-body radiation signature in addition to the sodium flare most predominantly seen in the visible range. As part of the black body radiation phenomenon of hot items like melting glass, UV and IR is released at energy levels that can cause long term/cumulative eye damage, such as cataracts (please see James' book for a more comprehensive description). You need glasses, first, to protect yourself against flying glass bits (heat your glass too fast and it will pop....). Secondly, while plain safety glasses will attenuate most of the UV produced, ONLY eyewear specifically designed to filter out Infra Red will protect you from those harmful rays. Many folks either forget or are unaware that IR is as bad or worse than UV. Didymiums or better are necessary to protect your eyes from these harmful rays. Finally, some of the heavily silvered glasses can also produce light in the visible range sufficiently bright enough to be of concern. There have been some NIOSH reports published on visible light hazards as well as the hazards of both UV and IR.

Welcome to the obsession! It's engrossing, but not a casual or inexpensive addiction. Torch happily, but most of all, do your research and torch safe!

Linda

If you had ever been to a Glass factory in Europe then you might have seen with your own eyes, beads being made with out any kiln annealing. I personally know that almost all the the china lampwork (the little decorated beads with the release still in the hole) are not annealed. It's costs too much and in an object that small annealing is entirely unnecessary.
How are you able to dismiss the marble making companies? There are marbles made up to 1' in diameter, no annealing, they last forever. I do not think I have ever read or heard of an exploding marble hurting anyone.
To try to teach without through knowledge of the subject matter does not help the student, only confuses her/him.
There are a group of folks on the internet who will chastise anyone who even thinks of talking about compatibility and annealing issues when none of us really understand what is happening all the time.
I will continue to challenge any information that my personal experience does not back up.
Glass is amazing and we know only a little. Have your own experience, enjoy yourself.
HITK,
Kurt