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

Well that went really badly!

Set the cloth up dry, trimmed, cut and checked it would lay down without any wrinkles - wet down the surface and then applied the cloth. All went downhill from here! wrinkles appeared in areas that didnt before, and after 30mins of struggling for it to sit flat (without then lifting in the corners!) I gave up and pulled the lot off, I just have an epoxy painted pattern now - luckily it's salvageable! I can imagine it's very easy on something with light curvature, but my part has a lot of curves....

Any tips? I cannot possibly see how I can get cloth down nicely on the part! Maybe I needed to cut it into more sections?

Very disheartened with it all

James

Hi James,

• What weight cloth are you using - 163g 2/2 twill glass?
  
• Which resin - our Epoxy Coating Resin?
• What is the shape of your pattern - can you post a picture?

You're right that some relief cuts may well have been in order; there is no reason not to put some relief cuts into the scrim cloth otherwise, depending on the shape, it may well be difficult to get the cloth to stay sat down wrinkle free on the surface.

Get back to me with the above info and ideally some pics and I'll gladly point out what might have gone wrong because essentially if you're using a light glass and epoxy resin that should be a reliable way to scrim a foam pattern. I look forward to hearing back from you...

Matt

Matt Statham
Easy Composites / Carbon Mods - Technical Sales