Injection molding

[Anonymous]

Anyone out there injection molding with urethane or similar products? One of the magazines had a recent article about a fellow who used a pressure pot to mold a steam set up/tender. I've never tried anything like this and thought it might be a nifty challenge.

Any comments?

Thanks
Chris

[Anonymous]

Hi Chris,

I cast urethanes for a living, been doing it for about twenty years. I've tried "injection molding" thermoset resins and never had any real success with it but always suceeded in creating and incredible mess. I think folks are trying to obtain intricate detail by trying this technique.

When free-casting, little air bubbles get trapped in the small sections and prevent resin from filling the mold completely.

I've always gotten good results by spin-casting, the same process used to cast metal... only using urethane resin.

It's a simpler rig to set up, and you don't need a compressor. If you have an old lazy-susan bearing you're halfway there.

Lew

[Anonymous]

Tell me more Lew !!!

I have been casting small details with a hot pot using molds I made with water putty.

I would like to try urethane. Can I use an old record turntable? What do I need to make the mold with? Any advice would be appreciated.

Kevin