Here are some products / options that might be useful as a starting point. This is a Clear (thin) epoxy resin by System Three
Clear epoxy that can cover bare wood or glass cloth over wood. It will give a very clear coating. Some epoxies have a slight haze or amber tone when cured, that can effect the finish. This is not a concern when finishing with paint.
The wood will absorb the epoxy to give years of Water proof protection.
But the epoxy needs to have a protective coating as mentioned from UV. Paints or Clear coatings. To have the wood grain show through these coatings a good clear epoxy covered by a good clear Interlux
coating will provide a beautiful finish.
Link is to Jamestown Distributing, they know their stuff. I'm sure they could recommend a few top choices.
I have not used this particular product but I have used plenty of the Interlux brand products over MAS epoxy with great results. (Brightside, Bottom Paint and Primers) Many brands and products to pick from.
I would use this combo on wood to get a good clear UV protective coating. But it's one of may choices.