I'm working on some CNC cut foam patterns, and after some advise on which products/methods to use to get a suitably surfaced pattern for taking the mould...

The surface isn't perfectly smooth, with many small pockets from the machining process - see attached image (slightly worse in places)

My original plan - (and have ordered these bits) was to use your epoxy coating resin with glass bead & silica and then brush/spray onto the surface - do you think that will be sandable to a suitable surface finish? should I be looking at adding some 163g woven glass over the part? These are largish parts for car bodywork...

Many Thanks,
James

Hi James,

If you're considering scrimming with glass first (which I think you should) then do it first! - If you put a decent finish on using just a gel finish and then decide you need a glass scrim cloth (usually to add strength to the pattern) then you'll spoil the finish of the pattern with the glass and have to then resurface that with filled resin/gel.

Single layer of 160g glass and epoxy resin straight onto your pattern. Cure it off, give it a quick flat

--Matt

Matt Statham
Easy Composites / Carbon Mods - Technical Sales