can you use a resin part to make a mold of with rtv rubber or will it hurt the resin part
yes you can, but use a mould release agent appropriate to the rtv rubber,
…assuming you mean Room Temp Vulcanising rubber.
If you have to heat the rubber to cure it, use Silicone cold cure, as sold by Sylamaster & others
The stuff sold to modelers, such as the stuff from Micro Mark, works fine with resin patterns. I use a thin layer of talcum powder as a mold release. The silicone does not stick real well to anything but itself, so mold release is most important if you make a two part mold, but it doesn’t hurt to use it on the pattern, too.
tanks for the info
spelling bad thanks for the info