- Shopping
- Buying stainless steel for high heat uses in glassblowing
is an adventure in minimum purchases. I discovered used
steel places and Southwest Stainless, Garland TX, which has
no minimum, and then never bought the tubing I priced.
Be aware that there is pipe and there is tubing. Tubing
is sold by Outside Diameter (OD) and wall thickness so it might be
exactly 0.75" OD with 0.25" wall, leaving a 0.25 hole. Pipe
is sold by nominal size - 1/4", 3/8" or 1/2"
water pipe is about 1/2", 5/8" and 3/4"
OD - to match older and other kinds of pipe.
Stainless Steel - Precision Steel
- Martensitic - Hardenable Chromium Steels (Magnetic). This group
includes types 403, 410, 414, 416, 420, 431, 440A, B and C, 501 and 502.
- Ferritic - Non-Hardenable Chromium Steels (Magnetic). This
group includes types 405, 430, 430F and 446.
- Austenitic - Non-Hardenable Chromium Nickel Steels
(Non-Magnetic in the annealed condition).
This group includes types 301, 302, 302B, 303, 304, 305, 308, 309. 310,
314, 316, 317, 321 and 347.
- Testing
- It is usually stated that stainless steel is not
magnetic, but it can be, especially when machined.
Magnetic stainless conducts heat very well, so it should
be skipped. If labeled, the types wanted are 303 and 306 stainless. The stainless wanted for glass work is not
strongly magnetic, so the first test of surplus metal
should be a magnet. If the metal is machined, it may have
a mild magnetism, but not a strong one. Holding the metal
near one end, use a lighter to apply some heat to the
metal near your hand. No heat should be felt in the metal
(a lot will be felt on wrong stuff.) After the metal
seems promising, a small propane torch will provide more
heat, taking the end temperature much higher than the
lighter will. The difference between conduction and non-conduction
is clear and remarkable, be prepared to drop to metal in
a safe way but quickly.
-
- Buckets
- Many shops, including The Studio at Corning, use lovely
heavy stainless steel buckets for glass collection. Upon
researching these, I found them to cost $85 or more each!
So I looked around for other sources. The Store I work at
put stainless soup pots on sale in just the right size
for $5.99! They are, of course, much lighter metal and
have two handles rather than the one of the pails, but
they also have lids and over all have worked out quite
well. [2003-03-01 It turns out the rivets holding the handles are some
junk metal that corrodes fairly quickly when the pot is full of (warm)
water. After mine gave up, I replaced the rivets with 1/4" stainless
steel bolts.]
- Welding
- Welding stainless steel requires special rod and
protecting the joint while working. I am told it is easy
with at TIG or MIG welder (wire feed, gas cover), but I
found it tricky the only times I did it with a torch, to
fill in the end of pipe to reduce the hole opening. A smaller
torch tip and Solar Flux, which costs a bunch If
you weld stainless steel you'll love Solar Flux"
In 2003, I got some stainless tubing and solid and made my first full home
made pipes. Described here
MSC has stainless steel standoffs that I used
to make small knobs.
K&S Metals includes stainless tubing and rod.
The tubing I have used is 304 alloy in making glass
sword handle.
Added notes
When you have a kiln, you will find you can preheat the
chunk of glass to annealing temp, heat the end of the pipe in
the glory and pickup the glass from the kiln on the pipe with the
small amount of glass that stays stuck to the pipe. You
are experiencing the old type of pipe (iron) that gets very hot
and flakes iron oxide. If you don't have a pipe cooler, you
may need one soon. Call around to Steel - Used places in
the Yellow Pages and see if any of them have got any 1/4", 3/8"
or 1/2" stainless steel water pipe on hand. (The
sizes given are about 1/2", 5/8" and 3/4" OD) Some
places never have it, some get some occasionally. If you haven't
checked the link below, look at it. In using pipe I found
why blow pipes have a small hole with a large area of metal on
the end as it is trickier to get a good shape of bubble with the
larger hole, and having the thin metal provides less glass and
thus less heat mass in the neck area of the piece. I welded
in a couple of mine and drilled a smaller hole, but still work
regularly with standard 1/4" water pipe just cut square.
Mike Firth
Furnace Glass Web Site/Hot Glass Bits
stainles.htm
----- Original Message ----- From: "cej" <chris@chocolatefetish.com> To: "Mike
Firth"
Sent: Thursday, August 02, 2001 6:29 AM Subject: Re: failure
notice
> Mike,
> Sorry for all the trouble with my email address.
Thanks for the reply, I
> had completely forgotten about ohms law, which is odd
> because I am studying for my ham radio license (second time,
first one
> expired). I am in the process of setting up the studio
> now, and will start dismantling the kiln I bought to make a
smaller
> kiln/annealer, glory hole, etc.
> I have to tell you that I love reading your site, I think
I've been through
> every page! Hot glass bits is great.
> I identify with your 'guerilla' style of glass, a different
approach than
> most people take (following instructions, etc).
> You would appreciate the furnace/glory hole I built. Its
made from a turkey
> fryer surrounded by fire brick.
> I have produced about 40 small vases. I have to heat the
blow pipe ($3 steel
> pipe at Lowe's) and the glass by laying it
> at the opening, then stick the pipe to the glass and turn it
until it melts
> to the end of the pipe (no crucible, yet).
> Hopefully will have a furnace from the kiln bricks, plus
annealer from
> bricks and the left over electrical.
> Total cost of my glass blowing outfit is less than $100.
>
> Thanks again, I will do some math and start to get the
electrical planned
> out. BTW, I do plan to get 220 to the studio soon!
>
> Regards,
>
> ~ cej ~
> http://hip.fresh.nu/stuff/glass/
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