Hi Tom,

Yes, it would be perfectly possible to make a new 'master' out of clay and then use RTV silicone rubber to make a flexible mould of this master. Once you have your silicone mould then you could cast polyurethane resin into it to make your rigid PU parts.

From our range you could use either our CS2 Condensation Cure Silicone Rubber or our Addition Cure Silicone Rubber but I would suggest the CS2 unless you have a specific reason to use the addition cure because it's slightly cheaper, is inhibited by fewer materials and comes with a faster catalyst.

You would not need any release agent to prevent the silicone from sticking to your clay master; silicone sticks to virtually nothing. Likewise, you would then also not need any release agent when you can your pu resin into the mould; it will releaae perfectly.

If you need pigments for your pu casting resin then we've just added them to our range here: polyurethane colour pigment pastes.

I hope this helps and wish you all the best with your project.

--Matt

Matt Statham
Easy Composites / Carbon Mods - Technical Sales

you can work with high density polyurethane foams

im wanting to make product . it needs to be very strong and made from polyurethane. i understand i will need to make a silicone mould but my problem is here... i cant use the model i have now as i need to make it much small and since its made of rubber its impossible for me to do this. so im wondering is it possible to make a replica of the model using clay or some thing like this. then using the clay model to make the silicone mould. then i can make many of them out of polyurethane. Tom