metal and boro

gabrielle · #1 2011-11-11, 3:08pm

Want to make little metal hooks, wich I can use in small boro objects.
Tried stainless steel, but it doesn't seem to stick. After cooling down, the hooks get loose and fall out.
Can anyone help me, what to use for boro or how to use it?

LarryC · #2 2011-11-11, 4:37pm

Will the hooks be mated with the boro hot or glued later?

menty666 · #3 2011-11-11, 6:51pm

you're better off making a hole large enough for the piece and then epoxying it in later. Boro and metals don't always play nicely with each other.

gabrielle · #4 2011-11-12, 1:22am

Metal hot, glass very hot, then I push them in. When the glass comes out of the oven, most of the hooks are loose and fall out.

gabrielle · #5 2011-11-12, 1:25am

When I would make a hole large enough and then put in the hook later, can I use uv glue?
(Bohle 682 T is special for glass and metal)

Alaska · #6 2011-11-12, 2:07am

Did you get any positive results if the stainless is heated red hot and then applied to the molten glass?

gabrielle · #7 2011-11-12, 4:51am

Quote:

Originally Posted by Alaska

Did you get any positive results if the stainless is heated red hot and then applied to the molten glass?

Yes, that's the weird thing, some of the hooks stick perfect!
But some people tell me that boro won't accept strange material.
But I also use dark annealed steel wire for boro and then the glass sticks like glue! This annealed wire, is unfortunately to soft to make hooks with.
I just want to find out if its a hopeless enterprise I've started? Or is there any hope I can use all my expensive boro in the way that I want?

LarryC · #8 2011-11-12, 8:40am

I would glue it in later on as tom suggested. There are issues of compatibility between the glass and metal hooks.

gabrielle · #9 2011-11-12, 9:23am

Quote:

Originally Posted by LarryC

I would glue it in later on as tom suggested. There are issues of compatibility between the glass and metal hooks.

ja, but why?
Has it to do with the exspansion rate ( wonder if thats a good word) of the glass and of the wire?
It seems that, when the object comes out of the kiln, the holes are to wide for the wire. So the wire has a bigger expansion rate then the glass. It sets out to far, and then cooling down shrinks again, but the glass doesn't shrink as much.
Are you still with me?
But what happens then, when I make the glass white-hot and put in the wire just warm, but not hot at all? So the wire won't expand to much.
Think with me now, please!
I'm just the beginner, you're all the pro's!!!

AmorphousDesigns · #10 2011-11-12, 9:47am

I'm pretty sure the glass will stick to the stainless steel (SS). Bead mandrels are made of SS and must be covered with bead release to prevent that very thing from happening. When I've deliberately used a bare mandrel (pulling twisties for example), the SS rod is heated to dull red hot and inserted into a white hot mass of glass. It sticks. It seems the real trick is annealling long/slow enough to prevent cracking from the 2 different COE's of the glass and metal from stressing each other out.

All that being said, your best bet is probably gluing the metal in afterwards.

gmarv · #11 2011-11-12, 9:49am

why don,t you do a google search on glass to metal seals it will give you a more detailed answer. but the expansion rate of boro glass has few metals that match so now you have to try to fool the two to stick togather.seems to me it has to do with oxidizing the metal. you might try copper wire.

gabrielle · #12 2011-11-12, 12:03pm

I did some google search already, but I can't find a good answer.
But that's a strange thing about glass, it will stick, when you don't want it to! Forgetting your beadrelease...you will need a hammer.....but make little hooks in little boro objects....hmmmm, makes you wonder, doesn't it?!!!

LarryC · #13 2011-11-12, 12:11pm

Quote:

Originally Posted by gabrielle

ja, but why?
Has it to do with the exspansion rate ( wonder if thats a good word) of the glass and of the wire?
It seems that, when the object comes out of the kiln, the holes are to wide for the wire. So the wire has a bigger expansion rate then the glass. It sets out to far, and then cooling down shrinks again, but the glass doesn't shrink as much.
Are you still with me?
But what happens then, when I make the glass white-hot and put in the wire just warm, but not hot at all? So the wire won't expand to much.
Think with me now, please!
I'm just the beginner, you're all the pro's!!!

Annealing does NOT fix stress due to material incompatibilities. You may be able to get some to stick hot but there is still a mismatch that may later cause the glass to split. Copper seems to fit at times with soft glass so if you are intent on doing this instead of gluing I would try some copper wire.

menty666 · #14 2011-11-12, 12:49pm

Just be careful if you use copper, when you get it into the flame it releases noxious stuff. That doesn't stop me from using it, but it does mean I make sure everything is well under the ventilation.

Oh, and I have had it loosen too when I tried using it for button shanks. I think the problem is that it firescales and *that* sticks to the glass while the metal within comes free.

gabrielle · #15 2011-11-12, 1:13pm

it's not that the glass splits or cracks. The hooks just are loose and fall out, when the glass is annealed.

gmarv · #16 2011-11-12, 3:11pm

i think the thinner you can get copper to be it will actually flex as the glass and copper contract at different rates, since you ain,t trying for a air tight seal you might get away with it.

lillip · #17 2011-11-12, 4:26pm

Nichrome wire works well when using it in fusing soft glass pendants- maybe it would work for boro. Haven't tried it.

LarryC · #18 2011-11-12, 5:24pm

Quote:

Originally Posted by menty666

I think the problem is that it firescales and *that* sticks to the glass while the metal within comes free.

Like bead release.....Ahh. We use copper with 96 COE soft glass in the hotshop quite a bit. We dont get it anywhere near as hot as in the torch, though.

ginkgoglass · #19 2011-11-13, 6:37am

Nichrome -- it falls out too. It also does melt in the torch since it is hotter than fusing temps. Stainless steel sometimes works and sometimes doesn't and may also crack your piece. I have some pretty cabinet knobs that are cracked because the glass was added right on the knob insert.

Gluing in the best choice for keeping it in there and I haven't found anything better than two part epoxy.

gmarv · #20 2011-11-13, 7:25am

yeah gluing is the easiest to do , but experimenting is the greatest teacher there is. can be a hell of alot of fun [if it don,t drive you crazy first].

ginkgoglass · #21 2011-11-13, 7:32am

^^^^^This is very true. I always tell people, don't let anyone tell you it can't be done that way. Try it anyway, because it may not work, or you may discover something no one has thought of before.

nklt0 · #22 2011-11-15, 5:27pm

try use titanium wire with boro. I read it some where that it works and I've had some luck with it. Alternatively, tungsten works with boro, but doubt you can bent a hook out of it easily.

Don't bother with silver, copper etc, they are somewhat compatible with soft glass and obviously no good with boro.

loco · #23 2011-11-16, 4:48pm

The coe of the metal and the boro is to different. I did an experiment with around 300 pieces, trust me it cracks! It works well in 104 using .035 stainless as well as some nails.