Fiberglass overlap bumps

Not quickly. Takes about 5 to 10 years to turn your resin into powder. Quicker if it is on the hot sun all day long.

 

Yeah. Uva is only about a millimeter but infrared can penetrate a couple inches. But I plan on a uv protectant clearcoat.

 

Is there some confusion here about making the mould dark or the boat dark or is the confusion mine?

 

Nope we are good. I was slightly aware of it and wanted to ask about it. I did a fiberglass interior, dashboard door panels , console, some years ago in gloss black. Sun dried it and saw the small warpings a few days later.

I'm taking it that anything below corvette red is a no go unless it's a carbon fiber or aluminum hull.

 

As far as non epoxy surfboards you can sand down dark boards and see more cracking than on light colored boards. Epoxy seems to hold up fine on surfboards even with dark colors, but are often treated with a uv protectant coat.

 

Polyester surf boards are most often made with base resins that place importance on being clear and easy to work with rather than good physical properties. There are better resins but their color and clarity are less appealing.

In clears the UV rays can penetrate into the coating or laminate, but once pigments are added the penetration is minimal, especially for any color made with a white tint base. Black is frequently used behind light colors because it is much easier to see air bubbles on a black background, plus it acts like an additional layer to prevent print through. Barrier coats do a much better job of this, but good ones can cost more than gel coat.

One of the difficult to overcome things about about polyesters and VEs is that there are so many different formulations designed for specific purposes that even knowing if one is available for your exact needs is difficult.

If you know you want excellent cosmetics and strength, there are resins available, but even finding a person that knows what is available for that application is difficult.