Judy,
My main medium is glass (lampworking and fusing), so I’ll try and
take a stab at answering your question from a “rod” angle.
The main concern you’re going to have is that the glass rods "work"
at 1400 F and melt around 1550 F, depending on the type of glass, so
you will have to be very careful not to soften the headpin when
applying the glass. I do know that some beadmakers actually make
their beads around silver and copper tubing with no problem. Of
course that’s tubing, not thin wire.
Here’s how I would try and do this technique:
What you’ll need:
-
Glass rods: Use a soft glass because of the lower melting
point. Effetre (Moretti), Bullseye, and Czech glass are the common
manufacturers/types. Effetre will be the easiest to find and is not
expensive. I would not use borosilicate (pyrex) because it has a
working temperature of 1700 F.
-
Protective didymium glasses. These protect against the sodium
flare given off by working the soft glass. They run around $35.
-
Some form of propane torch, preferably a glass torch so you’ll
have both hands free. You can’t use acetylene with glass because
it’s too dirty a fuel, at least that’s what I’ve been told by several
glass teachers. I haven’t tried it myself, but I believe it to be
correct. Since you’re going to be working very small, there is a
torch called a hothead which fits on the small benzomatic propane
bottles. These aren’t very expensive (about $30 or so). You’ll find
it much easier if you can secure the bottle. Some sort of
stand/holder is available for this (try
http://www.artglass1.com/index.htm if you can’t find a local
lampworking supplier). If you want an oxy-propane set up, the
National 3A + stand or the Nortel minor are the next, least expensive
torches ($100 - $150 + hoses).
-
Vermiculite (Home Depot garden center should have it. It’s
mixed in with dirt for potting plants. It’s also a good insulator
that doesn’t burn from the heat of the cooling glass. You’ll need
enough to fill a large metal can (coffee cans are good). Some
beadmakers put it in a crock pot and set the crock pot on low.
-
Something to hold the headpin while you work it – such as a pin
vise?
Once you have all that, then
-
Since the head pins are small, I would slowly encase & layer the
head with very small amounts of glass. To do this, first you want to
"pull a stringer". You can buy stringers instead of rods, but the
color selection is limited. The store where you buy the rods will
probably be able to explain how to pull stringers. It’s not hard.
You can try and use a full size rod, but you’ll probably wind up
applying too much glass to the top of the headpin.
-
With a low, neutral flame, first dip the end of the stringer
quickly in and out of flame to gradually warm it – don’t get too
close to the surface of the torch. Soft glass fractures if you heat
it too quickly: it will either spit glass fragments at you or
"explode".
-
Next slowly introduce the glass more directly into the flame
until the tips starts to turn molten. Doesn’t take much heat with
stringers. The glass will glow.
-
Next pass the head pin quickly through the flame a few times to
warm the metal.
-
Then, keeping the headpin out of the flame, get the end of the
stringer molten again and touch it to the top of the headpin. The
molten glass should adhere to the metal without melting it – I
think.
-
Let the glass on the headpin solidify, then apply a bit more
glass. Repeat until you have the amount of glass you want. Also,
occasionally pass the top of the headpin through the flame to keep
the glass encasing it warm. If you let it cool too much, it will
crack.
-
Last, put the encased top of the headpin slowly back in the
flame to shape it, if needed. Molten glass, like molten metal, likes
to be round. Be careful not to melt the glass completely. Soft glass
works very easily and will melt in the 1/2 second you take your eyes
off of it.
-
When you’re satisfied with the shape, take it out of the flame
and let it cool some. You’ll see the real color return to the glass.
I would wait about 10 sec? (you’ll have play with the time) then
bury the head pin into the vermiculite. The trick is to let the
glass harden completely so the shape won’t be ruined when you put it
in the vermiculite, but not to let it cool to the point it will
shatter.
After making beads, I always kiln anneal them. If you don’t they
usually crack because the glass has been so strained. Since you’ll
probably be applying a very small amount of glass, you might be able
to get away with out doing so. You’ll have to make a few and then
work with them. If the glass casing on the headpin starts to crack
into pieces, you’ll have to anneal them the new ones you make.
Hope I haven’t left any steps / considerations out. Probably did.
Let me know what you eventually wind up doing. If I have time, I’ll
try and experiment with some brass headpins I have. Got a pretty
full schedule, but you’ve made me curious.
BJ
