Silicone comes in a whole bunch of "flavors". The stuff you buy for
caulking should
be pretty good for adhesion to most materials except plastics.

Some info that might be of help...

Add glycerine to the silicone you buy at the hardware store and you
get something that can cure without exposure to moisture. Four drops
per ounce, I think, is the right mix.

Use some sort of parting agent with this and especially any of the
PU products.

RTV silicones made especially for mold making (two part) are readily
available.
Usually cost in the order of $25.00 a pound.

The Yahoo group "casting" deals with this sort of thing.

My web site has pointers to a couple of books about mold making.
Look under resources.

DOC

Have robots. Will travel. http://www.robot-one.ca

On May 11, 9:46*pm, "Michael Koblic" wrote:
While experimenting with making rubber moulds from silicone caulking I
bought in Home Depot (not even the good stuff!) I found that the compound
adhered to mild steel with indecent tenacity. I had to throw two objects
away because the "mould" adhered to them in spite of my best efforts to
remove it.

I filed this experience for future reference. If one needed a strong joint
of two metal components with some "give", this seems worth considering.

Has anyone used silicone caulking or similar such to join metals?

--
Michael Koblic,
Campbell River, BC