I read that one should use glosss varnish because stain varnish does not filter out UV and therefore does not protect the epoxy. But I don't like the look of gloss and the glare it produces is unpleasant.
My question how important is this; or how much exposure to the sun with satin varnish will the epoxy degrade. Consider say I use the boat once a week for about an hour and the boat is on top of the car for about a total of an hour . So both the hull and deck sees about an hour a week from May to October, about 24 hours. Add say three float trips a year five hours each totaling 40 hours a year with the boat in the basement the rest of the time.
Does anyone have any data or experience to answer this?
Jim,
It sounds like you are concerned mainly about protecting the epoxy below (which is, after all, the main role of varnish). The answer to that, I think, is to apply a few coats of gloss varnish for UV protection and then put a coat or three of satin varnish on top of them. I did this for the cockpit of a kayak recently once I realized how dramatically the gloss varnish highlighted the tapes seams and whatnot, and I have no complaints so far. I've heard many others recommend the gloss/satin hybrid approach too.
Now that I think about it, though, I didn't realize/remember that satin has fewer UV inhibitors (though I don't doubt thaglt it's true). I think that satin varnish tends to degrade faster because you miss out on the mirror-like reflection of gloss varnish (and instead get more light absorption - i.e., UV damage), but at 40 hours a year, I bet you could go many, many years between varnishings.