Carbon fibre and epoxy uncoated has very little UV protection and will yellow and break down quickly in the sun.
It seems most of the major foil makers have no UV protection applied to the carbon fibre parts and therefore they need to be kept out of the sun when not in use. Car manufacturers of carbon fibre bonnets etc apply a urethane2 k clear coat to their parts to protect them from UV damage.
I had replies from both Slingshot and Armstrong to say that none of their carbon fibre wings ,mast etc have UV coating and they both suggested keeping the out of the sun or putting the covers on them when not in use.
Given this I wet sanded and applied 2 k clear coat to all my foils so I don't need to worry.
Its probably not a big deal unless you leave your foil on the beach etc after use etc or plan on owning them for a while. Any solid pigment painted carbon is the best protected from uv damage like gofoils.

Thanks kobo. Good to know. I have to reseal a tiny leak in my Neilpryde foil. After sealing with epoxy I might spray over it with an automotive clear that I have. Just have to check if it is the type you suggested. If not probably a good idea to get some not only for foil but also board repairs too. Cheers.

As long as it's a clear coat that has uv blockers in ,then all good.Im referring to mainly the black carbon fibre that you can see the cloth weave,that needs protecting. Anything that has already been painted a solid color ,eg white,red,blue etc is fine and will have enough protection until it become chalky and needs another coat.

Well I can see the black weave in the Neilpryde main Glide wings.
Also now wondering about the carbon paddles that are also left in the sun usually?

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Seajuice said..
Also now wondering about the carbon paddles that are also left in the sun usually?

The should NOT be left in the sun! Please use paddle bags.

Actually, UVs will reduce the life of everything and should be avoided if possible. There are mitigating measures (paints, varnishes), but they only slow the degradation.

Good quality 2k automotive clear , will significantly protect substrates from uv as it does for metallic car finishes , but solid pigment white is the best of all. Both are way better than nothing , but I guess it's an extra cost no manufactures are prepared to do.

This is what Sunova boards thinks of 2k clear coating sunovasurfboards.com/en/technology