Somebody suggested to me that I should cast my spaceship models (more on that here) in polyurethane. I'm not that experienced when it comes to different types of plastics and resins, so what can you guys tell me about it?
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I usually use something like this. It has about a 5 minute work time and can be removed as early as 10 minutes, although needs 15-20 minutes to fully harden. Removing it earlier is great for cutting flashing or anything that needs to be trimmed while it is soft and pliable.
If you sand it, be sure to use a mask as the dust particles are bad for you. It is smooth, shows beautifully when you want to show something with clean lines and detail and paints really nice.