hello. is there any DIY silicone mould texturing technique availible?
thanks i advance.
As in a flexible mould made of silicone, say for PUR parts, or a hard mould made for moulding silicone rubber?
It would be pretty tricky to get a fine texture on a flexible mould, especially one that doesn’t rip out every third de-moulding. I’m sure there are techniques though.
If it’s the hard mold you’re referring to – silicone often has problems keeping a fine texture because little chunks can fall off all the time, but you could pretty easily carve the texture in, or sand it, or something. You’d probably have quite a bit of leeway with draft, etc. as well as it’s so flexible.
If you are making the mold out of silicone, and casting into it, there are a few options if you haven’t already made the mold. Silicone is extremely hard to get anything to stick to, which is why it makes such a good mold material, so if you’ve already made the mold your options are pretty limited. There are some paint tecniques that you can use if you’re painting the parts after you cast them.
If you haven’t made the mold. Keep in mind that if you use a good quality RTV, it’ll pick up anything that’s on the surface of your origional. Fingerprints, hair, scratches, if it’s on your origional, it’s in the silicone. So if you put a texture on your origional, it’ll come out in your cast part. Be careful though, some primers do stick to silicone.
thanks Arclight. its flexible silicone. i’m trying to make a mould to cast side handles for a chair like the ones below. its actually a metal 3/4" frame but i’d like to cover circular part with foamy resin for a better grip etc. texture will do fine as well as it can hide any degassing probs. i dont think its going to be a problem with demoulding if i’d design 2part mould. but still…have no idea how to make a texture :o/
thanks JWK.
its RTV mould. at the moment in “conceptual” stage 
i’d like to get a texture you’d normally see on the handles of any common office seating chair. i’ll ty some “high density” postal bubble-wraps wrapped around master soon.
I recently saw a demo from a Model shop in the US that did some really cool things with simulating Overmolding. Which is one possible way to get that “foamy resin” feel.
Basically, you make two molds. A substrate and an overmold, then use two different types of urethane to cast the parts.
There is a flexible urethane that feels a lot like rubber. So that’s an option for you as well.