I’ve made a silicone mould of a thin part (roughly 1mm thickness 100mm long)

Mixed the px90 at 1:1 ratio, and poured it into the mould.

3hours later I went to demould it and it’s super flexible (I can scrunch it up like paper) and I can rip it !

Isn’t the px90 supposed to be hard ? Is my part too thin to use px90?

Thanks

Shore hardness and flexibility are 2 different properties.  Although often related in materials - ie often a hard material is also rigid, this is not always the case.  

You may in this case be better off looking at a rigid PU resin? If you want it quite tough (some fast cast resins are brittle in thin sections.) then look at something like our Xencast P6 Toughened Polyurethane Casting Resin

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant

Thanks a lot for your response would the xencast p6 be flexible enough to take light impact without snapping?

Being a toughened PU resin, it is likely to be ok depending on severity of impact, thickness cast etc.  It is certainly a lot tougher than your typical PU casting resins.

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant