I've tried making rubber silicone molds, using clay with a liquitex acrylic varnish coating. I tried spraying a mold release (magic chems silicone lubricant/mold release) on the master/container, which was sticky on the surface contacting where I sprayed. I'm actually unsure if this product is necessary for one part molds, or just for 2 part molds and casting. It made the surface sticky for the second part of a 2 part molds as well. Is this just a bad product? Am I using it wrong?

My most recent attempt was a one part mold and I did not use the release spray, it has been curing for over 48 hours now at ~78°F and the inside of the mold (contacting the master) is not dried at all and still very sticky. I removed it from the container, all exterior parts are fully dried and not sticky (making me think the spray I used for the first attempts was what caused them to be sticky). I left the master in just because of how wet the interior still was, I didn't feel good removing it out of fear it would cure to be bumpy. This master was also out of air dry clay with the varnish on it.

Could the varnish used also be contributing? If my master is air dry clay, do I need to put anything between it and the silicone mold? The silicone used was bought from Amazon, lets resin was the first brand and CT (changtikeji) was used for the one part mold.