Inclusions

[Celene]

I'm interested in fusing inclusions into my glass, but it's unclear to me whether it can be done in COE 96 or COE 90 glass. Everything I read about regarding inclusions, suggests using float glass. Does that mean float glass is all I can use with inclusions? I want to add aluminum tooling foil and copper wire to my COE 96 glass that is cut and ready to piece together, but I'm still unsure if I can add the metals. Any info would be good! Thanks!

[Morganica]

??? I'm not entirely sure what you mean by inclusions. In casting, inclusions are bits of prefabricated (by casting, lampworking, etc) glass that are inserted into the mold. When fired, they become a part of the piece.

Inclusions can also be metal foils, wire or other non-glass items, and they can be used with any kind of glass. You must be careful not to make them too thick, because they are liable to expand/contract at a different rate than the glass and could crack it.

If glass, inclusions should always be the same type of glass you're using for the rest of the piece...unless you're gluing them in, or you have a design that calls for fractured glass.

[Bert Weiss]

Inclusions must have a close or higher COE than the glass around them, if the surrounding glass is going to remain intact. If you plan to reheat the glass, they better be close. If you don't reheat, there is a greater range of leeway.

Copper foil works fine, but a piece of thick copper wire might not.

The "catseye" in a catseye marble is glass with a higher COE. This puts the sphere in a state of compression which makes it a lot stronger. That is why these marbles work so well in a game of marbles where you smack glass together. Glass is very strong in a state of compression, very weak in tension.

Look at the work of Bertil Vallien. He casts clear furnace glass with inclusions, both glass and copper. Some of these are massive in size. I once saw a picture of a giant crane loading a solid glass boat hull, in through an upper story window of a tall building, in NYC. His pieces are annealed and then never reheated.

[RachelM]

So interesting about the marbles. Never knew that but always learning.

Rachel

[Judd]

Celene:
I add aluminum foil to 96 COE glass all the time. No big deal. Copper wire can work if it's really small, like 22 or higher gauge wire. As Bert said, copper leaf seems to work better. Experiment.

[haleybach]

I'm interested in fusing inclusions into my glass, but it's unclear to me whether it can be done in COE 96 or COE 90 glass. Everything I read about regarding inclusions, suggests using float glass. Does that mean float glass is all I can use with inclusions? I want to add aluminum tooling foil and copper wire to my COE 96 glass that is cut and ready to piece together, but I'm still unsure if I can add the metals. Any info would be good! Thanks!

Yes, it works with 90 or 96 COE.

Copper wire works, I've tried several gauges and all worked in one way or another. I've used 17 gauge but nothing thicker than that in wire form. You can hammer your wire to flatten/thin it a bit if you are worried about thickness. Shape first, then hammer.

Copper might bubble, I find bubble size depends on the wire gauge. The copper may change colors.
Copper mesh works as well. Copper foil has an interesting effect.

I have used copper to make hangers for ornaments, the exposed wire will blacken but is easily cleaned. Often just wipes off. Just do not try to bend or form it after you fuse it as you have basically over worked the wire, so it will be somewhat brittle and where it exits the glass will be a weak point.

Brass bubbles madly and I find the effect ugly.
Tooling aluminum I have not tried.

There are other nonmetal things that can be sandwiched between glass as well.

[Celene]

Thanks so much for all the great advice! I'm going to give it a go!

p.s. I didn't know that about the marbles either. Very cool.

[Bert Weiss]

When metal is extruded in to wire, it is work hardened. When you heat the wire red hot, you take that hardness out of the wire, annealing and softening it.

[rosanna gusler]

like bert said. wire after firing is 'dead soft'. it i usually hammer it a bit with something plastic or gently bend it to re stiffen. ... yhe long time at high temp does cause oxidation. that fire scale you brush off is made from what was part of the wire. i find that wire drops about one gague in diameter after firing. ... there are many alloys of brass. some do just fine in the kiln... i fuse all sorts of differing thickness of copper and brass into glass with no problems. .. r.

[Celene]

Thank you! I'm so glad people on this bulletin are so willing to share their knowledge! I've been reading tons of literature, but sometimes it helps to be able to ask someone about something!