how thick do you make your mold?

Don't want to see this ad? Sign up for anRPF Premium Membershiptoday. Support the community. Stop the ads.

CVWcreations

Active Member
Quick question, how thick do you make your silicone mold and then how thick do you make your plaster jacket for it?

This would be for making a helmet.

Thanks.
 

Don't want to see this ad? Sign up for anRPF Premium Membershiptoday. Support the community. Stop the ads.

Crank729

Sr Member
I think the general rule is that the silicone should be 1/4 inches thick, but this can also depend on how many copies you need to cast from your mold. Are you planning on pulling 1 cast or 20? If you only need to make a handful of casts, a thinner silicone jacket should hold up fine...If you want the mold to have some longevity, then anywhere from 1/4 to 1/2.

I can't chime in on the plaster jacket since I've only ever used Plasti-Paste for my molds.
 

propninja

Member
The first shop I worked in used burlap soaked in plaster to make mold shells. They could be upwards of an inch thick or more. Personally, I use polyester reenforced fiberglass.
785630525_2788452815_0.jpeg

like this
 

zorg

Master Member
RPF PREMIUM MEMBER
as a rule i try and get a wall thickness of at least 10mm that way the chance of distortion is reduced. i have had molds that were 5mm and sometimes under and it always produced a poor quality product. i use a fiberglass mothermold for everything also. keeps the weight down.
 

NormanF

Master Member
RPF PREMIUM MEMBER
This is based on Rebound 25 from Smooth-On. Different rubbers will be different, but I would recommend 1cm or 3/8in thick. For a mold that will just sit there you might be able to make it thinner, but if you are rotocasting you might want to go even thicker. The first mold I made for rotocasting was too thin and and the cast part looked like it had been in a hail storm. And of course the master got destroyed when I made the mold.
 

Don't want to see this ad? Sign up for anRPF Premium Membershiptoday. Support the community. Stop the ads.

Daniel Nelms

Sr Member
RPF PREMIUM MEMBER
Rebound is pretty hefty stuff so you can go thinner. Some is a lot softer and you have to go thicker. It also depends on what you are molding and what kind of mold you are making.
 

Don't want to see this ad? Sign up for anRPF Premium Membershiptoday. Support the community. Stop the ads.

Top