I'm not sure an automotive clearcoat would give you enough UV resistance to protect the Epoxy.  Plus, damaged finish would be a lot more difficult to repair then just smacking a little varnish on a couple spots.  

 I don't have any hard and fast evidence for this... just an idea of what you might be up against. 

 ~Chris 

Here's a link for someone who tested an auto clearcoat (and other finished) for abrasion resistance; don't know if he actually put it on a kayak, but you could ask him:

http://clearstreamwood.com/WordPress/kayaks/canoe-and-kayak-coating-abrasion-test

Interesting tests, but not sure how valid some of them are. He's definitely misusing the S3 WR-LPUs.

For one thing, while they will stick to S3 epoxy without primer, a high-build primer is strongly recommended for S3 and mandatory for all other brands. For another, S3 recommends that they be sprayed for a high gloss coat, not brushed, sanded and polished. If you must sand and polish, S3 recommends gping to 4000 and 6000 paper before starting with the rubbing compounds. He only went to 1000. Finally, all S3 WR LPUs ship with an optional  cross-linker. When added to the paint it turns it into a 2-part system. By not using the cross-linker, he's left out most of the strength and hardness of the coating. Basically, with all this he's trying to put a square peg into a round hole and whining when it doesn't fit.

One good point he makes, though, is about the toxicity of isocyanates.

S3 lets you avoid the toxicity issues. It's water reduced (no solvents) and availble as an unpigmented clearcoat with UV protection. While it can be used instead of varnish (with the cross-linker it's much harder than ordinary varnish) some builders think that it looks cloudy compared to a real varnish. Don't know, never used it over bare wood. Used over crosslinked paint and S3's 2-part high-build primer it makes a very tough and glossy coat which has survived impacts with docks..

I used the S3 system on the inside and sides of my boat and graphite/epoxy on the bottom and am quite happy with how it all worked. I think you'll like their topcoat. Wish CLC would carry the S3 products.

Laszlo

Some of the guys taht build Glen-L wooden runabouts have used automotic clear coat, I think. Here is a write up on one of the build pages.

John

There are enough uv inhibitors in automotive clearcoat to protect the epoxy and I've seen boats done that way. As was mentioned previously it's pretty difficult to refinish them if they get scratched. I'll stick with varnish. More is written on this on Nick Schade's forum at Guillemot Kayaks, just do a search.

George K

I have been in the  auto body industry since 1969 the clear coats for autos  are very easy to repair today if you have ever work with them and have the equipment and place to spray i'm trying to get the interlux gold on my petrel and it is much harder then auotmotive clear  to get to lay flate and not run on the sides but i do not have a place to spray most of the uv protection from auotmotive paint comes from pigment in the color(remeber the peeing paint on late 80 and early 90 GM vehicles)  and the shine of the clear reflecting the uv rays off