Pre heating molds

[Trevor86]

Hey guys.

Does anyone pre heat their molds? If so to what temperature. Does it give you more consistent results?

[Fleafa]

I don't as it would make the resin go off faster than I would be able to deal with!

[mangozac]

I'm in the same boat as Fleafa - the resin goes off fast enough as it is! I guess if you were casting is super cold weather it might be good to do. I do know of people post heating the moulds to help the resin cure faster. And indeed some resins (particularly transparent products) require post heating to get perfect results.

[Fleafa]

When I had a microwave in my workshop, I did actually heat a couple of moulds one winter. Didn't notice a big change in quality, just speed.
I actually have to 'bake' my moulds after demoulding the master since I switched to Smooth-On. First few casts otherwise have a sticky surface. Very odd. Never had this problem with any other resin. I thought it may be the condensation (tin) cure silicone I am using so tried an addition (platinum) cure silicone. That problem went away but the surface was always pitted and had strange discolouring. I could mitigate that a little with talc, but ended up dumping the platinum moulds.

[TomG]

As I remember, you can preheat mold, when you cast white metal. We have in my country company,. that makes silicone, primary used for that and it is recomended to preheat it and slowly cool it. when silicone hardens. Then you can use it for white metal and if you preheat mold white metal has more time to flow into details of mold.