I have had some success pouring water clear polyester resin into a RTV silicone mould of a vehicle light cover. The cover is only about 2mm thick and so flow is not easy.

The completed cover is fine in detail but being so thin is brittle and easy broken. Two questions please; will water clear polyurethane resin be much stronger and less brittle plus will it be more or less pourable into the same mould?

The polyurethane is stronger and should be fine with the detail.  It can be poured down to 2mm thick so you will be ok.  Only downside is PU is very sensitive to moisture so you can't use a condensation cure mould, it needs to be addition/platinum cure silicone.

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant

Warren

Many thanks for your prompt response. On further measuring I note the wall thickness is as low as 1mm. I take it from this you don't have a suitable material?

Regards

It will probably cure with a little added heat but it is a bit thin.

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant

Warren

\I will give it a go and have ordered some water clear polyurethane resin. I note other companies have a regime of post curing resin with heat. Will that help your resin and if so what parameters please?

Regards

Ray