I had thought you meant you had a rubber stamp. Metal won't stick to
it. It should work beautifully. If it is a flat stamp, the back is
flat, even better. Clean clay is clay that doesn't have sulfer in it.
Sulfer will cause the RTV silicone to not cure. So regular modeling
clay etc. won't work. I'm not sure where to get it, but I can find
out. I got mine from a class I took. I'll ask the instructor. But if
you put a thin layer around the bottom of the stamp, it will stick.
And it cleans off, so it won't affect the harm the stamp. It's clay,
but it doesn't ever harden. Amazing stuff.
Aluwax is a dental wax that has aluminum in it, so it retains heat
longer and can be manipulated with the warmth of your hands. I use it
for freeform twisty pieces that I sprue and cast. It's a dental wax
used for filling molds and stuff, I think.
The RTV silicone is liquidy, goopy honey consistency; mixed with a
liquid catalyst which starts the curing process. The only reason you
paint on the first layer is so you can see bubbles and eliminate
them. Then you pour the rest of the same stuff into the mold. You
could just pour the stuff from the beginning, but you end up, with a
detailed mold, with bubbles on the surface of the model, which then
end up cast in silver and need to be ground off, negatively affecting
What you end up with is a slightly flexible mold that you melt wax
into. The silicone withstands temperatures up to I think 400 or 500
degrees, so a soldering iron won't affect it, and you can use it hot
or cold. You can get RTV stuf on ebay for around 15-20 dollars a
quart I think. I can find the website for you. I need to order some
more. But you only use a couple of ounces for each mold, depending on
the size of the piece you are making a mold of.
If you want to try it, I can find the info on the websites. Let me
But use rubber gloves, because the stuff can be messy, and it
doesn't come off anything. It's like honey, but it's rubber when it
cures. Put down paper towels and mix it in a throw-away plastic cup.
Measure precisely and when you're done, throw everything away. Easy.