Bristol is a two-part urethane that produces a very high gloss.  I used a fair amount of it on the teak on my Catalina 30, after trying multiple other coatings...but that was over teak which some people will say never looses its oily nature, thus making coating harder.  The first year (in Texas hot sun) was great, the second year some chips started appearing, and by then I didnt want to maintain any finish and sold the boat (not the only reason!). Supposedly touch ups with spot feathering sanding produces a different color for the repair than the adjacent original coating.

The customer service folks at Bristol are excellent, and if I were you I'd explain your project to them, type of wood, will it be covered when not in use...etc etc and let them coach you up why Bristol may be better than Interlux Varnish for  your specific application.

My Interlux varnish on my trip on my NE Dory is holding up real well and it's been out in the sun a lot.  I've also found that spot touch ups come out good.

One more thought...I just found out that Lowe's sells a Rust Oleum spar varnish for $13 a quart...I'm using that for a rudder I'm building...dont know if it will do better than Interlux but you may want to research that too..

There are a lot of builders here that have done a lot of coatings....look forward to what they have to say.

Good luck...keep us informed what you find out.

Curt

Curt,

Thanks for an informative response, I contacted Bristol Finish, told them I was building a kayak, that their product would be applied over a MAS epoxy base, and that the boat would only see sun about 3 weeks per year. There response follows.

"Thank you for your interest in Bristol Finish. Yes you can apply Bristol Finish over the MAS epoxy. The Traditional Amber has more than enough UV protection for what you have in mind. I do not know what you latitude is but in the Northeast using the 6 coat minimum under the conditions you describe it is not unusual to have customers getting at least 4 or more years and have had instances of 8-10 years of life for the Traditional Amber. 

Let me know if you have any other questions. If you have a few minutes tell us how you heard about Bristol Finish and post some pictures of your project on our Facebook page or email them to us for posting on our website."

I sent a similar email to Rustoleum inquiring about their Marine Spar Varnish. If they respond I will post it here.

Mike

   I live in Florida. I use the boat all year.  The sun is a problem but gravel, oyster shell, deck mounted gear and boat ramps are more of a problem.  Personally I'm not using any two part finishes since I'm often patching up some scratches.

   Good point, Grumpy, about not wanting to do small touchups with any 2-part finish...I was thinking that when I wrote my reply but your pointing it out is important.

Mike...the difficulity in repairing 2-part finishes is this...if all you want is a little finish on an artist brush to touch up a small chip it is all but impossible (and expensive) to mix up a very small "batch" of a 2-part finish.

Curt

Thank you Grumpy and Curt, good information.

Curt, I sent an email to rustoleum and their spar varnish will not work below the waterline, it might not work out on your rudder. Their response.

"Thank you for contacting Rust-Oleum Product Support.  You would be able to use the Marine Spar Varnish on fully cured, prepared epoxy but it cannot be applied below the waterline.  The only thing I have for that would be our Marine Boat Bottom Paint.  We do not have a clear for submersion."

   Ah yes...the "below the waterline" discussion ...there are a lot of posts on this topic, but here is the official answer from CLC RE: Interlux Schooner Varnish:

"The instructions on the can say "Not for use below waterline," which causes some confusion.  What Interlux means by this is that it isn't for big, heavy boats that live in the water for months or years.  For kayaks, canoes, dinghies, rowing boats and so on, which never spend more than a few weeks at a time in the water, there is no issue and we've been using it on Light Craft for 20 years.  If your boat is going to live in the water, you'll need "antifouling" paint, anyway."

Also:
"Please read our shop tip: The Varnished Kayak. While written for kayak builders, the information is a propos for anyone varnishing over epoxied wood."

I opted for a true bottom paint but that is a separate discussion.

Curt

  Curt, Thanks for the information. This is a very big project for me and I have been reading everything. I will paint the hull and varnish the deck.  I just got word that my kit has shipped but, unfortunately, they have not shipped the tools and building supplies I ordered. I sent them an email asking them when they plan to ship. It will be frustrating to stare at the parts and not have what I need to put it together. I will be able to start but I will not get very far until it all arrives.

Mike