Gel coat additives

Small custom boat builders are a very small, and I mean tiny, portion of the market.

Some use gel coat, more use paint, but there is a difference in commercial work boats compared to pleasure craft. Commercial builders are far less worried about cosmetics than they are cost and durability, so they may use gel coat and mix in some solvent, more likely just surface agent or Patchaid.

Patchaid is a product added to the gel coat that has about lowest number of negative affects of any product. It uses the same base resin as the original gel coat with no thixitrope added (these products thicken gel coat so it can be sprayed on a vertical surface at 20+ mils and not sag), they also have ingredients to enhance the cure so it will cure well in a thin film, it will also have a surfacing agent so it will be tack free. They aren't perfect though, they are somewhat clear, so you are still reducing the amount of pigment, they counter this by adding some UV inhibitor to help it from yellowing. These products help it level and cure without reducing the physical properties of the gel coat like solvents and clear additives can.

High end custom pleasure boat builders tend to use paint.

 

Thank you so much for the education. I'll look into patch aid.

 

well after 20 hours of dry time the sample part looks great it feels dry and hard to the touch but how do I know it is in fact fully cured?

 

There isn't much more you can do.

 

Sand it and see if it loads up the paper........?

 

I tried sanding it and it doesn't load up to much but I tried a little acetone on a rag and it did turn the rag a little white. will it eventually cure? after all they say if you let to much time pass between layers of laminating resin you need to sand to scuff the surface?