Casting and mold questions

captain shelley · Post by **captain shelley** » Sun Jun 27, 2010 10:09 pm

I have never made a mold for anything before. I saw a few starter kits at Hobby town and I figured to ask everyone on here what is a good beginner kit to get for making molds of parts? Thanks.

captain shelley · Post by **captain shelley** » Tue Jun 29, 2010 9:40 pm

anyone?

Jagdson · Post by **Jagdson** » Tue Jun 29, 2010 10:10 pm

Smooth-On has basic A+B sets that're often found in art supply stores. I forget the part numbers. The rubber sets up decently and the resin is easier to use than measure-by-weight varieties. 'Bit pricey, though.

Ziz · Post by **Ziz** » Tue Jun 29, 2010 11:43 pm

I've been learning the molding and casting process the past few months. Smooth-On's OOMOO rubber is a 1:1 mix ratio and comes in "fast" and "slow" versions. The slower one gives you more time to pour the rubber and, if you're using a vacuum chamber, get through the degassing process before the rubber starts to set. That said, I've been using the faster rubber with mixed results, considering I'm still learning. One other trick I learned for "naturally" degassing rubber is to pour it into your mold from 2 to 3 feet high. That will make it pour in a very thin stream, which naturally removes a lot of air bubbles from the rubber before it hits the mold.

As far as resins, check their SmoothCast 300 and 320 series. They're all 1:1 mix ratios too, again with different work times depending how fast or slow you operate.