Hi all,

I'm currently working on a set of headlight covers. 
What I'd need to know if anybody has any experience with this is,  will 'EG60 Epoxy Tooling GelCoat' attack ( or even stick to ) PETG plastics ?
I've seen a couple of YouTube videos using similar products ( EC's and Mathiew Libert's ),  and it looks as though they used it directly onto ABS plastics.

Also,  is it OK to use Monster Clay ( sulphur free ),  as a gap 'filler', or is it necessary to use Plasticine?
A better explanation of what I'm doing ( bottom of page ) > Quad Headlight thread

Thanks


TURK

Not overly familiar with PETG, but if it similar to acrylic then I'd be careful as epoxy will actually bond somewhat to acrylic. Epoxy won't attack anything as there's no solvents in it, but it will stick to some plastics. Not super well, but enough to make life difficult. Its likely that the plastics you saw in the videos were polypropylene rather than acrylic.


As for the clay, I'm familiar with Monster Clay and it should work fine.

Epoxy really shouldn't react to anything except polyurethane at elevated temperatures, and possibly moisture if there's enough of it. Monster Clay being oil based means it is fine, and plasticine should be ok as well. Softening or the clay shouldn't be too big a drama either, realistically the yellow filleting wax that EC sell will also soften with body temperature but it isn't until it gets up to about 70-80 degrees that it actually softens enough to cause problems and in most cases by this time the resin has gelled anyway.

All of that said, I would use plasticine before I used monster clay. 

Hi Hanaldo,

'Filleting Wax' ! .........  I hadn't thought of that one   I've got a big block of it somewhere.  I think I'd rather use that or Plasticine over Monster clay as well.  I have to use a soft pliable material on the inside corners of the mould,  as I can't vacuum form a right angle,  so a completed mould with sharp 90° corners is a big no no in vacuum forming.  With your guidance and understanding of what I'm trying to achieve has been most helpful,  I thank you for your time.
I usually approach what I read on the internet with scepticism,  but on this forum,  and it's members like yourself,  us newbies can rest assured that the information is pretty accurate    You have put my mind at rest.

I actually need the high temp EMP160 as I'm simply making a mould in order to make some tooling plugs for vacuum forming.  So I'll be making the tooling plugs using CS25 Condensation Cure Silicone Rubber,  and casting Vac-Cast Epoxy resin into them.  This should in theory give me a positive of my headlight covers with twin headlight apertures in them.  Then I can vacuum form dozens, or even hundreds of sets of headlight covers  

I know it's a long winded way of doing things,  but I really have no choice in the matter,  as my current prototype headlight cover plug,  is constructed with the original headlight glass!  >>


Literally dozens of coats of Patter-Coat-Primer,  loads and loads of sanding,  and I've got a pretty solid prototype mould to work from.  But for obvious reasons I can't put two headlight apertures in these,  hence the reason why I need another mould.


TURK