Still another resin question

[swimmin' for shore]

Still learning. New question for the day:<br />I understand how gelcoat is made. There are dyes and filler materials for both epoxy and polyester resins. If you add a dye to an epoxy and are able to get the color that you need, do you still need to paint, or is it sufficiently UV resistant? I'm going to do some small repairs for someone, but I don't want to have their "paint" change color after some time in the sun.

 

[fishingdan]

Re: Still another resin question

The major brands and most small company brands of boat building epoxy do not have any uv inhibitors. There may be some small specialty epoxies that do, but I am not aware of them. <br /><br />Epoxy will start to break down fairly quickly in the sun without any protection.

 

[ondarvr]

Re: Still another resin question

Even true under water two part epoxy paints will chalk and fade in direct sunlight. Gel coats are loaded with pigments (15 to 22%) and fillers to combat UV rays, not normally UV inhibitors. The pigment you add to the epoxy will help and most likely any problems will only be cosmetic, fading and loss of gloss. But if this needs to have good cosmetics for a long period of time, you may want to paint it.