I plan to replace the wood on the railing cap of our deck. Instead of the usual caulk I was thinking of using polyurethane to seal the joints. Poly is more expensive, is this idea good?
Also instead of priming and painting the ends of the wood after I cut them, I was thinking of using that clear wood preservative, because it would be faster. But would caulk stick to a wood surface that has been sealed with preservative?
If you are using pressure treated wet lumber it will not work to well with anything sticking to it until it has a chance to dry out some over time. A good construction adhesive - Glue at the seams/joints will not hurt though..
Many times we have been installing composit decking on top of the top rails.
It acts as a protective cover over the wood so there's no more splitting and slivers to deal with.
Constrution adhesive and screws coming up from the bottom, not the top makes for a nice clean look.