Question about mold release...

[Hecubus114]

ok, now that I have my "clay wont come out of the mold" situation under control, I have a question about casting/mold release. When I use spray on mold release, it leaves the casting REAL shiny/glossy. And its not just mold release on the casting, even after I wash it thoroughly, its still very glossy on the surface. This makes painting very difficult. Is there something I could use instead of the spray on mold release that would give the casting a more flat finish? Would baby powder do this?

 

[CustomCreations]

ok, now that I have my "clay wont come out of the mold" situation under control, I have a question about casting/mold release. When I use spray on mold release, it leaves the casting REAL shiny/glossy. And its not just mold release on the casting, even after I wash it thoroughly, its still very glossy on the surface. This makes painting very difficult. Is there something I could use instead of the spray on mold release that would give the casting a more flat finish? Would baby powder do this?

You should be getting a matt finish off your spray really, unless it actually says it gives a gloss finish?
I use j-wax spray, which is non silicone based matt wax spray. If you get a gloss finish, its in the surface finish of the mold itself, of maybe you have used too much spray. Most of the spray release I have used need only a few light coats wafted around the mold face....are you sure you even need a release agent (if its a silicone mold?)

 

[Rebelscum]

As I've been working hard to actually get glossy casts, a couple things I learned along the way. I have limited experience with the whole process but here's what I've learned.

Glossy smooth model use no mold release on it = glossy mold. Glossy mold with no release prior to casting = glossy cast surface. With a silicone mold casting plastic you should never need mold release however, if you want a cast with a satin finish, even using a glossy mold, ease release 200 aerosol spray will give you that finish.

In this example, I used smooth-on mold max 30 for the mold and both urethane and resin casts.

I have no idea what happens if you put powder in a mold you're using to cast plastic. I've only used talc when casting pewter, which works great.

 

[hodge1001]

If its silicone you shouldn't need a release agent. Try using mirror glaze wax for fibre glass. rub on then buff off. About five layers does it. failing this you can use wax spray then talk your mold heavily and use an airline to take away the talk leaving you with a matt finish. I personally use a vinyl spray that puts a physical barrier between the two surfaces. It comes as silver and then spray macwax over the top of this. Not only does it demold easily but you can almost peel your clay out of the mold.

Hope this helps

As I've been working hard to actually get glossy casts, a couple things I learned along the way. I have limited experience with the whole process but here's what I've learned.

Glossy smooth model use no mold release on it = glossy mold. Glossy mold with no release prior to casting = glossy cast surface. With a silicone mold casting plastic you should never need mold release however, if you want a cast with a satin finish, even using a glossy mold, ease release 200 aerosol spray will give you that finish.

In this example, I used smooth-on mold max 30 for the mold and both urethane and resin casts.

I have no idea what happens if you put powder in a mold you're using to cast plastic. I've only used talc when casting pewter, which works great.

 

[Hecubus114]

good info guys, thanks!

 

[Strofmos]

I've got several types of mold release for different type of applications.
It all depends on what you use as master product (plastic, wood, resin, clay,...), your mould product (plaster, silicone,...) and what you want to cast in it (plastic, resin, urethane foam,...)
If you don't know what to use, inform with your mold-products supplier.
They should know what you have to use for a specific application