Making a silicone slush casting from a silicone mold

[chewbaccadoll]

Hey all, been a loooong time since I’ve been here, but I knew if I wanted the right advice to go to the RPF!

I have a hollow, plastic head (about 2” by 3”) that I’d like to make a mold of and then make a silicone slush casting of in order to make a mini rubber mask to pull over a figures head. I know using silicone with silicone is a no-no, but my model is hard plastic. I’ve read it can be done using a release agent, but would love some advice/guidance as I’ve only made traditional silicone molds/solid resin pulls. Here’s a quick sketch for a visual aid. Thanks in advance for any help!!

-Kurt

 

[JPH]

Hey all, been a loooong time since I’ve been here, but I knew if I wanted the right advice to go to the RPF!

I have a hollow, plastic head (about 2” by 3”) that I’d like to make a mold of and then make a silicone slush casting of in order to make a mini rubber mask to pull over a figures head. I know using silicone with silicone is a no-no, but my model is hard plastic. I’ve read it can be done using a release agent, but would love some advice/guidance as I’ve only made traditional silicone molds/solid resin pulls. Here’s a quick sketch for a visual aid. Thanks in advance for any help!!

-Kurt

Use DragonSkin 10 fast to make the mold of the original.

Make a hard outer shell with Freeform air in 2 halves.

Slush cast in Task 16 rubber.

I just slush cast a Daredevil helmet like that

It has a short pot life, but slush for a good 10-15 minutes per pour Use teeny amounts and do a couple of layers.
It is mixed by weight, so 0.2 oz of part B and 0.1 oz Part A.

Pigments go in the white B side.

Once it is opened, it goes bad in weeks.

 

[animator]

If you want your final casting to be silicone, I have a couple of suggestions.

First off it is always worth calling Smooth-On support for their advice.

If you made the mold with Compat 45 and cast the part in silicone, you won't have an issue with them sticking together.

I do cast thin silicone parts in a silicone mold but am careful to fully spray a couple coats of a mixture of dish soap and alcohol as mold release. I then demold the part under running water to keep from tearing the silicone.

I have never tried to slush cast silicone and don't know how that will work. I would consider making a core for the mold which will be easier to cast and control the final parts thickness.

 

[TazMan2000]

Make a two part mold of your head using plaster.

TazMan2000