COE 33 sheets?

[Milica]

I'm searching for glass sheet, which have excellent heat resistance.
Until now I find only borosilicate tubing and rods. There is Borofloat
from german Schott, but I'm not sure if it's what I need. And also
as can see it's so, so expensive. I'm starting to think there is not
that type of glass.

Thank you in advance and regards from Slovenia

[Otter's Flame]

The only sheet glass in 33 COE that I know of is the Borofloat but you say you are not sure if it is what you need. So orher than Borofloat I don't know of any.

[Three Muses Glass]

Can I ask what you want it for?

[Milica]

Yes, I will try to explain in my not so good English, hope you will understand.

What I'm trying to do is to cut a piece of glass abut 3cm x 3cm (have made a experiment with Bullseye and Effetre) and slowly introduce to the flame of my torch, with the propose to deform the form a little, to obtain curved shape, instead of flat glass. But it was impossible, because the glass cracks or turns yellow, no metter how careful I am. I also try to prefuse the glass, and then when to work in open flame, then return to the kiln, the result is the same. And finally, 2mm Moretti or Bullseye do not have this transparent,
reflective look at the end, like boro have - I use tubes and rods sometimes, so I know the difference.

[nevadaglass]

So If I understand you correctly you are trying to take a flat piece of boro sheet glass and have tried heating it in a kiln, then place it into the flame of the torch. You are trying to get it in a curved shape, but when you take it out of kiln and try to work it in the flame, it either changes color and yellows or it cracks completely.

What temp are you heating it to in the kiln? 3 cm x 3 cm isn't that big ( A little over an inch square) so I would guess its not hot enough or its cooling too fast before you work it in the flame but that's just a guess. You should heat to approx. 1100 degrees farenheit or 593 Celsius before trying to work it in flame. Keep the entire piece hot while you work and don't let any of the corners cool off or else it will crack when the flame touches those cool spots. Also "flashing" it in the flame (waving it back and forth thru the flame) will help heat it up more gradually rather than sticking it right into the flame if it has cooled off slightly. It's more forgiving that way.
Does this make sense?

I understand about effetre, moretti, system 96 and other 104 COE glasses not working in sheet form. They are very "shocky" in sheet form if you are trying to torch so Boro is easier to work with.

If you are going to try with effetre or moretti then you have to start way back from the flame and take it slow and constantly moving in and out of flame. Go slower than you think you should. Stay a ways back from the flame and don't rush - best guess - 15 to 20 minutes (that's probably an exaggeration but it will take a while - go too fast and CRACK!!!).

With 104 and 96 in sheet form, putting in the kiln, heating and then sticking in the flame usually doesn't work that great because its so thin, it cools off too fast so its shocky before you even get it to the flame.

By waving it in and out of the flame at the back of the flame ( way back) , It will heat up slower. Once it starts to glow a little then you can move closer to flame. It will take a while but it can be done.

An inch square isn't that big, it's just going to take time because its thin and therefore more shocky than a rod. Also keep in mind, it's thin so it will also cool off faster than a bead so that means you cant dilly dally after you are done torching - Finish what you are doing to it and then get it in the kiln to anneal - don't take too long admiring it - get it in the kiln - it's going to cool off fast so if you wait too long then try to put in kiln, its going to crack because the heat in the kiln will cause it to heat back up too fast.

Originally Posted by Milica

Yes, I will try to explain in my not so good English, hope you will understand.

What I'm trying to do is to cut a piece of glass abut 3cm x 3cm (have made a experiment with Bullseye and Effetre) and slowly introduce to the flame of my torch, with the propose to deform the form a little, to obtain curved shape, instead of flat glass. But it was impossible, because the glass cracks or turns yellow, no metter how careful I am. I also try to prefuse the glass, and then when to work in open flame, then return to the kiln, the result is the same. And finally, 2mm Moretti or Bullseye do not have this transparent,
reflective look at the end, like boro have - I use tubes and rods sometimes, so I know the difference.

[Hammer]

You can get Boro plate from Chemglass. The smallest size is 1" * 1" . You can also get discs.

[menty666]

You might consider pulling a point of thin wall boro tubing, open one end, scissor down the length of it and flatten it. It's cheaper than buying boro float glass and easy enough to do over if you happen to make a mistake.

Schott's one of the more common manufacturers for sheet boro, but you can find others out there if you dig. Here's a piece of borosilicate (theoretically) on eBay: http://www.ebay.com/itm/like/230982729767?lpid=82

[Milica]

Nevadaglass, thank you so much for your advices, will be useful when for my next projects I didn't use Boro, only Bullseye and Effetre, because I can't find Boro plate to bay. This is main problem. What I'm trying to make is impossible with soft glass. I will attach some photos of jewelry I find on Internet (not mine), so you can see what I want to make.

Hammer, thanks, will try to search for Chemglass.

Menty, please look the photos, I don't think (or don't know) it could be made of a tubing.

[Milica]

Not a kind of jewelry I'm making (not my style), just to show clear glass parts

[jamie lynne]

Are you sure those aren't fused or slumped?

[Three Muses Glass]

They could be slumped if you took sheet glass and suspended it, leaving the center glass free of any molds, fiber or kilnwash so no texture imparts. I mean a large piece, it would be very difficult to do that with such small pieces. It sort of looks like (the jewelry pieces) it is cut and polished drinking/wine/water glass.

[nevadaglass]

The raised edges on the glass make me think its been torched because the edges are slightly raised, similar to the edges of wine glass rims on some of the pieces all the way around them, but If I were doing these, I would fuse/slump rather than torch them.

There are slumping molds out there that could make those shapes on small pieces of glass. Check out slumpys.com
specifically - http://www.slumpys.com/Warm-Glass-Mo...liday&top=1075

You could do it with bullseye sheet glass. Go to bullseye.com and check out their firing schedules. You would probably be better off trying this in a kiln specifically for fusing rather than one for annealing ( like bead kilns) since the temps on bead kilns typically don't go high enough to slump glass. You may want to take their schedules and slow the ramp times down a bit ( The first 3 or 4 ramps) I don't know about bullseye but with system 96, I have had to slow down the first few ramps on some colors to keep them from cracking. Most of the schedules put out by glass manufacturers are specific to their glass and are usually pretty spot on but you do have to "tweak" since not all kilns are the same and run the same.

I haven't seen or found a decent one for effetre/moretti so I typically try to take my system 96 schedules and modify them ( slow them down when trying to heat up) ) since the 104 will be more shocky, softer and more sensitive to heat changes than 96.

I know for a fact you can do this since I made the schooner below about 6 years ago from a wine bottle and sheet glass: You will notice all of the sails are curved. I used a couple of different molds to shape the sails ( things I already had - bottle slumper, bowl mold etc )

Originally Posted by Three Muses Glass

They could be slumped if you took sheet glass and suspended it, leaving the center glass free of any molds, fiber or kilnwash so no texture imparts. I mean a large piece, it would be very difficult to do that with such small pieces. It sort of looks like (the jewelry pieces) it is cut and polished drinking/wine/water glass.

[istandalone24/7]

http://www.abrimagery.com/store/inde...s-c-424_425_50

[KA]

Originally Posted by istandalone24/7

http://www.abrimagery.com/store/inde...s-c-424_425_50

I was going to say Blastshield must get their borough plate from somewhere. Those rounded ones look like pre-dichoic blanks.

[Milica]

Nevadaglass, the schooner is amazing, what a great idea. I think I will bay big boro tubes, those with heavy walls, and try to blow just a little , break like shades and then to torch them. Or shape with my graphite tools. This is the cheaper solution for me in this moment.

Three muses glass, If that don't works, I will thy maybe with slumping technique.

[glassmaker]

I'm obviously a little late to this party, but I agree that using large diameter boro tubing is the best idea. Many years ago I made a glass schooner with sails similar to those on the one Nevada made. I did them out of boro tubing. It's pretty easy to cut with shears once you get it hot enough. Then you can reshape it from there.

Brad

[menty666]

This might give you some inspiration. It shows the old way of making flat stained glass sheets: https://www.youtube.com/watch?v=XiShcE0ez1o