Do not use cleaning solvent or Acetone thinning (diluting) resins or gelcoats as this can lead to added pinholes, surface problems and premature yellowing. If you need to thin the gelcoat you can use Poliya GTM (gelcoat thinner mix) you can find the details at Diluents and Monomers section or you might as well use styrene up to 2-3%. If you use more you will degrade the resin or gelcoat.
The main reason is you most likely stirred the color paste with a styrene, resin or gel coat contaminated stick or mixing equipment. Pigment pastes virtually does not contain any monomers to harden. Always you to clean stick to stir the color pastes.
Yes, definitely. Outer layer is the most important part in any composite product or part, low quality color pastes doesn’t have UV stabilizers and atmospheric protection additives. Even if you use the highest quality gel coat it will promote yellowing and fading you should prefer Polipigment 01 White for coloring or you can order Polijel 215 white ready to use.
The volume and the production depends on the product size, shape and technical specifications but briefly.
Low volume production: Open molding (Hand lay-up, Spray-up | Chopped laminating), Vacuum Infusion molding, vacuum bag molding, casting.
Medium volume production : RTM (Resin transfer molding), filament winding, centrifugal casting, wet lay-up compression molding.
High volume production: SMC (Sheet molding compound), BMC (Bulk molding compound), TMC (Thick molding compound), LPMC, Pultrusion, Continuous Lamination.
You can switch to vacuum bagging or resin infusion methods to reduce entrapped air, compact the laminate and homogenous resin distribution. You can find more details at the Resin Infusion Equipment and Consumables.
No, you should not because polyester resin chemical structure is not truly compatible with carbon and aramid. If you are planning to increase mechanical properties you should consider NCF’s with polyester resin. If you need to use carbon or aramid you can use with vinyl ester and/or epoxy resins for this purpose. You can find more information at the Reinforcement and Core Materials.