Try Spar Varnish, Varnish is better for outdoors. Marine varnish would be
good. Check to web for a distributor. I'm also looking for a a coating that
will hold up in weather for many years. I hear that there are clear coats
especially designed to hold up for many years. Varnish is good for about
five years or more if you use several coats. The problem with varnish is
yellowing. Good Luck