Mold Release agent for Shapeways parts?

[Hawk312]

I just had some parts printed from Shapeways in their "Frosted Extreme Detail" material. Do any of you guys have experience trying to make a mold from a part made from this stuff? It is only 3.5mm thick, and I have heard that this stuff can be brittle. So I am worried about losing it in the mold and shattering into pieces trying to get it out. Lately I havent been using mold release. But I have used baby powder in the past, and am thinking of using that again. Thoughts?

[Greg Wann]

When I make molds with small parts, I do the following.  I take the part and set it on a piece of KLEAN KLAY, a blue colored sulphur free clay.  The piece will be of a pyramid shape.  The "claying up" of parts is important.  This piece will get set on another clay base.  What I do once a mold box is made is to mix a small amount of silicone up and pour over small parts.  Even if there is a thin film of silicone it will cure quickly.  The thin film will keep the part from floating from it's clay stand so that it does not get lost in the mold material.  I too learned the hard way.  Doing surgery to locate a small rare part in cured silicone and not destroying it in the process is not fun.

[my66s55]

I use a tin-cure silicone r.t.v. from Smooth-On called Mold Max. It's made for making molds on various types of resin. Also I don't need to use a mold release agent. The u.v. cured resin I use to create prints on my 3d printers is very brittle and small, thin parts can break off easily. Be vary gentle removing the part from the mold and you should be o.k.     

[Spex84]

I have molded some parts from Shapeways that were Frosted Ultimate Detail (FUD). The only time I had trouble with parts not releasing from a mold was when I attempted to mold some tires with very fine, deep tread detail--the large surface area of the zig-zag tread grooves provided enough grip that it overwhelmed the strength of the rubber and I tore parts of the tread grooves out of the mold when removing the FUD part.
I'd suggest sanding the FUD or FXD parts to get the surface texture off before molding them, and this will also help them release from the mold.

 

[Mark]

If the "frosted" part has a texture all over, that's going to give it amazing powers to stick to the cured mold material.  If the texture isn't desired in the finished parts that will be cast, then you will want to smooth the part off as much as possible anyway.  That's true for any imperfections in any part you are casting.  Would you rather remove a flaw from one piece (the master), or from every single part that comes off of the mold?

When making molds, the only time I have used a mold release agent is when mold material is being poured next to already cured mold material.  The part itself shouldn't need it.