how can i make my own concrete stamp out of rubber?

Answer 1

Answer number one is certainly valid, and I offer another suggestion.

It make take a bit more research and eventual effort but you could find harder rubber sheeting, at a thickness that will allow my suggestion.

On a piece of hard rubber sheet you can free hand sketch outlines, etc, of ANY design you choose, then securing your piece to a pre constructed wooden base/handle, use a router with a sharp blade to achieve the desired results.

Rather than a mold you pour into, you'd be subtracting material from the rubber piece to eventually get the Stamp pattern.

Just a thought. I have never attempted it, but in ART,,, exploration can be as enjoyable in the exploration, as the destination,,, as in many other levels of life.

Steven Wolf.

Answer 2

You need to get molding compound and a release agent.
http://www.smooth-on.com has some quailty compounds for just such a purpose
http://www.polytek.com is another company with a range of rubbers
Get one with a shore hardness of 80 or 90 for a concrete stamp, it will hold up much longer to the abuse of being hammered into the concrete.

Both sites have instructions on how to set up your pattern piece and make a stamp from it.