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Using C clamps and a kiln as a vulcanizer?


#1

I have a Question. Instead of purchasing another expensive tool that
i really will not use but once a month. Could I use the Kiln that i
have (programmable) along w two C-clamps, two steel plates and the
aluminum packing mold to act as a vulcanizer?


#2

Yes. You can even use your oven at home (if you don’t mind a slight
rubbery smell). One of my students has had great success doing that.
Except that you may want to use aluminum plates, not steel. The same
ones you would use with a vulcanizer.

Emie Stewart


#3
I have a Question. Instead of purchasing another expensive tool
that i really will not use but once a month. Could I use the Kiln
that i have (programmable) along w two C-clamps, two steel plates
and the aluminum packing mold to act as a vulcanizer? 

Yes. Make sure the steel plates are thick enough so they won’t
deflect under the pressure of expanding rubber. And use pretty heavy
duty C clamps as well, so you can get enough pressure in the first
place. You can even do this in your kitchen oven. It only needs 320
degrees for standard rubbers. Might leave a temporary smell in the
oven, though…

The main thing with this method is it’s harder to get uniformity in
pressure from mold to mold, it’s clumsier, and slower. But yes, you
can do it that way. You may find an increase in the numbers of reject
molds since repeatability etc is poorer. But I’d not guess that to be
too much of a problem.

If you don’t need molds done that often, you can also just send the
models out and have the molded. Many casters will do that for you.
That way, you’ll likely get someone experienced in cutting the molds
to do that part. Cutting the things really well is the hard part.

And consider the pourable RTV (room temperature vulcanizing)
Silicone rubbers. No vulcanization step at all needed. Some of the
rubbers benefit from being vacuumed, but you can use the same vacuum
you use for investing. And these molds don’t shrink, so your waxes
are more accurate reproductions of the originals.

Peter Rowe


#4

Hello Michael, Use2 aluminum plates and 2 “c” clamps and your home
oven. Preheat the oven and take the mold out after 10 or 15 minutes
to retighten the clamps. Follow the timing listed on the rubber
instructions. I made hundreds of moldsusingCostaldo gold rubberas
well as no- shrink pink. The process works fine.

Have fun.
Tom Arnold


#5
Could I use the Kiln that i have (programmable) along w two
C-clamps, two steel plates and the aluminum packing mold to act as
a vulcanizer? 

Not your kiln, but your home oven and the C clamps, etc. will do the
job, if you are strong enough to clamp them down well.

Elaine
http://www.CreativeTextureTools.com


#6

Michael,

I have a Question. Instead of purchasing another expensive tool
that i really will not use but once a month. Could I use the Kiln
that i have (programmable) along w two C-clamps, two steel plates
and the aluminum packing mold to act as a vulcanizer? 

Quite reasonable. For a long time I used 2 plates drilled for bolts
in the corners and a curb side free toaster oven (not good for food
anymore !!!)

I switched to a vulcanizer which was too cheap to pass. But the
plates and toaster are much more portable, no comments about the joys
of moving a vulcanizer least there be children reading this :-).

jeffD
Demand Designs
Analog/Digital Modelling & Goldsmithing
http://www.gmavt.net/~jdemand


#7

I’ve done that and it works pretty well. I found that the plates I
used at first were too thin and bulged out (16 gauge or so), so I
started using 1/4" steel plates. That stopped it, but getting the
baking timing down so the molds didn’t end up either raw or
over-cooked was tough. What ended up working was to preheat the
steel plates and clamps in the oven to the recommended temperature
(about an hour or so), packing the frame using the thin plates just
like I would when using a vulcanizer and then using welding gloves,
clamping the whole thing together. It took an extra minute or so per
slice of rubber over the recommended time if I remember right. It was
a pain in the neck to hold the whole assembly together while clamping
it quickly enough that it didn’t cool down too much though, and I
burned myself quite a few times. Tightening the clamps a couple of
times during the first five minutes or so is also problematic, but
necessary for a good mold. Drilling an 1/8" hole in the side of the
frame helps the rubber squeeze out a little bit more evenly than
letting it ooze out between the plates, and makes for a better mold
with a little less shrink. Also, make sure you put something under
the frame to catch the squeezed out rubber or you might end up with
a stinky mess next time you burn out.

If you are going to make just a couple of molds, this method will
work OK, but if you’re making more than a few over time, do your
forearms (and your burn-out kiln) a favor and get a vulcanizer. With
all of the stores going out of business these days, I would think one
would turn up on EBay or Craig’s List every few weeks at least.

Or you could use RTV, if the molds aren’t going to be used for major
production. I haven’t used my vulcanizer more than a couple times
since the advent of good RTV rubber. No shrink (at least very
little), no burns, no timer to forget, and you can make molds of
just about anything, including wax and hollow parts. The only issue
is that they won’t last as long or produce as many waxes, but if you
keep the master (if you’re doing production model work and
mold-making and casting are a part of it, you should!), just crank
out another mold when the first one starts breaking down. I’ve had
excellent results with the Castaldo pink RTV rubber. Follow the
directions to a “T”, weigh the rubber and catalyst accurately when
mixing the rubber, when storing them powder them well inside and out
(or over time they’ll stick to anything they’re in contact with),
keep them clean, and in a cool, dark place and if they’re cut well
they will give you at least a hundred waxes and will last for years
of light to moderate use.

Hope this helps,
Dave Phelps


#8

Michael

Tim McCreight (sp?) covers how to do this in his book “the complete
metalsmith”, but using a conventional oven. Worth getting a copy if
you do not already have one as it is a great source of info. Can’t
remember the specifics myself.

CP


#9

Dear All,

You might want to see the extensive article on this subject on our
website at:

http://www.castaldo.com/english/usinprod/u_athome.html

Michael Knight
Castaldo