I’m looking to make the densest possible cold casting for a prototype that I’m designing. The final casting needs to be flexible.

I suppose iron powder would be the way to go, but the real question is, what is the maximum ratio of powder-to-resin that I can get away with before things fall apart?

Is there a particular resin that works better with higher ratios of metal to resin?

Any insight would be appreciated.

It depends how flexible you are looking at.  There are other metal options to choose from such as Brass which is slightly more dense albeit slightly more expensive that iron powders.

In terms of maximum quantity you can get away with, you are unlikely to find any data as flexibility will vary just as much as tear strength depending how much additives are used so it is kind of unique to the application.


Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant