No matter how you perceive it, boats have to handle a lot of abuse. Even sitting on a trailer, they are battered by rain, baked by the sun’s UV rays, and have to weather all kinds of temperatures.

Q:I am refinishing some wood floors and furniture with polyurethane varnish. How can I prevent tiny pieces of grit that form on the finish? Are those gritty pieces in the varnish or in the air? A: ...