Thin Bits and mold making

[Jamiew22]

G'day guys, girls and anyone else who cares to read this!
I've been casting some model train parts and some are quite thin (about .5 x 1 mm)
I've been having a little trouble with casts breaking lately as I pull them out of the mold. The only problem is, I've already cast about 30 with no troubles. The temperature has plummeted here in the UK in the past few weeks, so I'm not sure if it is something to do with getting cold and brittle, the mold getting old and sticky or if I just need a better mold release??
Any help would be greatly appreciated!
Also, does anyone know of any cheap pressure pots for pressure casting in the UK? I've looked around a bit but they are all quite pricey and I don't want to spend too much as I'll only be using it for a year.
Cheers ! Jamie W

[Fleafa]

Low temperature often results in brittle casts, unfortunately.
Cheap pressure pots can be dangerous. I have one of .

[mangozac]

The easiest solution is to pull them out earlier, before the resin has hardened too much (but after it's reached an optimal point of rigidity). I never do a cast if I know I'm not going to demould within two hours, as the harder the resin sets in the mould the more wear on the mould it creates while demoulding.

[Jamiew22]

Cheers guys, I'll have a play and see what I can come up with!!