Morning guys,

Please see my pics attached, imp having a problem withresidue being left in mould and making parts stick.

I believe it’s the spray mount I use to tack cloth in placeon the mould. I don’t use a lot but I’m thinking I won’t use any tack spray andlet the bag pull cloth into position.

Been using 3m re position able photo mount spray.

Does the epoxy resin react to this spray??

As sometimes resin has been left in the mould when I pulledparts out leaving me some porosity in the surface.

Looking at the pictures I would say the spray tack is the culprit. Even when used very sparingly it with have a negative effect on the surface finish. If you think about it what you are actually doing is spraying glue onto the surface of the part. Using a clear, in mould gelcoat such as GC50 from EC with have several benefits. Benefit 1- if you get the timing right the gelcoat will act like spray tack allowing you to stick the first layer of cloth down into the mould (you can use spray tack for subsequent layers if needed) Even if you miss the "window" to do that you can use spray tack (sparingly) without effecting the surface finish as the spray tack will be between the gelcoat and the part not on the final surface. Second Benefit- GC50 provides a UV protective very hard, very polishable finish. Downside- GC50 really needs to be spray applied as it will fisheye if applied by brush to a chemical release agent. This needs a dedicated gelcoat gun and compressor. Hope that helps.

Warren

Carbon Copies Ltd

Hi Wozza,

 

Thanks for the reply. I had thought i used itsparingly but i wont be using it on mould surfaces again!

Totally right about the clear gelcoat, webeen setting up to spray and will be ordering GC50 next time around. We havetried clear gel before and its really poor unless you can spray it on.

Plus like you say you get the benefit of tackto get the first layer secured nicely.

 

Its quite amazing what the spray does to themould, the epoxy resin dosent like it and i have found parts to stick and evenpull out lumps of mould.

My only thinking is that small traces ofresidue left from previous parts make it even stickier, or that the easyleasedosent like it much either and is inhibited by these traces left in mould.

You've got to be using wayyyyy too much. When I use it, I can barely see it on the mould surface. I put the mould down on the ground and give the adhesive a very quick spray from a meter above it, let the mist settle down on it. Works like like a charm, doesn't leave any residue on the surface and epoxy has no problems with it. 

That does seem like classic case of too much spray tack.  Less is better!

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant