rejuvenating silicone mold

[Gordon Gekko]

I have a silicone mold made from Smoothon Moldmax 30. The mold is a couple of years old, but is is great shape with no tearouts or anything.

However, the entire surface of the mold is covered with tiny little cracks. They are pretty easy to sand off the cast, but I was wondering if anyone knew of a way to "rejuvenate" it?

Thanks.


(mods: wasn't sure if this should go in general modeling or not. It is a prop mold. Move if you must.)

 

[GeneralMayhem]

Have you thought of spraying the mold with several coats of a silicon based mold release?

 

[monkeywrench]

I remember reading somebody recommended baking molds for a few hours in the oven at low temp to help rejuvenate old molds.....

Now that I think about it, I believe this was for flexibility issues, not cracks

 

[robstyle]

not much you can do for cracks except make a new mold. Baking it will bring out chemicals only if the silicone is thick enough and its not a guaranteed temporary fix.

 

[Jimbo890]

This topic comes up from time to time. No real solutions have been reported. Silicone mold release seems to be the most popular remedy, but really it just makes the resin castings come out easier.

I have some old PlaSil71-20 RTV molds that, after repeated use have done the same ting. Some mold release helps but it is a sign the mold's live is at an end. IMHO.

I have heard about the baking, but no temp or lenght of time has been mentioned.

Jim