Clear Coat™ and SilverTip™ Epoxy offer excellent barriers to both liquid and moisture vapor. They are easy to apply with a brush or a roller, and will cure to a tough, clear, high-gloss film, which will waterproof the wood.
Water Based Exterior Wood Stain Exterior 450 Outdoor
For a tough finish, use epoxy
System Three Clear Coat Finish - Woodworking, Blog
Behr Premium Transparent Penetrating Oil Wood Finish - Cedar
Epoxy Resin for Wood Xtreme Polishing Systems Blog
Matte Finishing Techniques
System Three RiverCast Deep Pour Liquid Epoxy - Canada's Log
3 Easy & water-resistant finishes
Exterior Wall Sheathing Options: The Ultimate Guide
Eastwood Rat Rod Matte Clear Quart Kit, Clear Coat
Eastwood Rat Rod Matte Clear Quart Kit, Clear Coat
Water Based Exterior Polyurethane Clear Coat: Exterior 450
Rust-Oleum 207008 Marine Spar Varnish, Quart, Gloss Clear
Black Forest Furniture Oil - Black Forest Wood Co.