I have made my first part using CG50 gelcoat, but it delamimate, so I wonder if it´s possible to spray epoxy resin in the mould instead off CG50, let it cure till it´s tacky, add reinforcement and then infuse?

Best regards

Keld

Yeh you can, but laminating resins don't have much thixo in them so they tend to run and pool quite badly, and will also separate very badly if you're using a high slip release agent. 

Thank for ansver, do you have any other suggestion than CG50?

I don't use any gelcoat when infusing, lay up dry into the mould, infuse, then just spray on a UV topcoat after

Thank you all, I´ll give UV topcoat a chance

Hi,

It could be a couple of issues causing the de-lamination.  Common issues include leaving the gelcoat too long, too thick gel, cool temperatures, incorrect mixing and incorrect mixing ratio.

In terms of using an epoxy, we do not have a specific epoxy gelcoat.  Using a normal release agent would likely cause problems as it is not thick enough to lay evenly on a chemical release agent, meaning a high chance of the resin fish-eying on application.

Many people will infuse without a gelcoat then either leave the parts as they are or use a UV stable lacquer or clear coat to give a final shine and UV protection.

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant

Hi Warren Thanks for reply

Yes we have after reading all post (a lot) regarding this issue, and figuerd out that there are too many parameters using GC50 for a garageprojcet as ours. The sollution I guess will be - infusing without gelcoat or epoxy as first layer.

Best regards Keld

 

We hawe now made some braking tests arround GC50 and delamination, and our Conclusion are that:

It´s very important to clean the surface with acetone or similar, then sand the GC50, and clean up again before infusion.

See our testresult in the attaced file

Please let us now if you think we are wrong.
Best Regards
Keld and Kurt

Are you using Easy Composites infusion resin? It will depend on the various chemicals you are using. Not all epoxies are the same, and while one could expect that an epoxy compatible gelcoat should work with all epoxies, that isn't really the full story. If you are using Easy Composites resin that is tried and tested with GC50, then it is strange and I would be tempted to say there's something up with the gelcoat. Plenty can be done wrong in manufacturing a polyester resin, so I wouldn't be at all surprised if it was a badly blended batch of the stuff. I'm sure EC can help you determine if that is the case. 

Hi Hanado, thanks for reply...

No we used a expoxy resin from DK, perhaps we should try Easy composites. Or just sand well

best regards

Keld