I suggest that you try marine Cetol. It doesn't look as spiffy as varnish, but is more durable to weather and sun than any varnish I have used. The beams and posts of our carport were finished with the non-marine version in 1996 and still look perfect. I also used it on a cedar address sign in front of our house about five years (likely more) ago, and it still looks fine as well. I would highly recommend it for a wooden sign. One issue I have had with it on our boat is that it seems to be intolerant of standing water. As long as the design of your sign doesn't cause water to sit against the finish for weeks at a time, it should last for many years.

Good luck,

Allan Edie

: Just got a call to refurbish a mahogany sign I made for an office
: complex back in the '90s. It gets sun all day. I'll have to do
: it on site.I'll sand it to bare wood with a ros, but I'm not
: sure what to finish it with. I'm leaning towards using Flagship
: varnish, thin the first application, sand lightly and put on
: several more coats. What I need to know is if there are better
: choices for refinishing, as I'm not current with what's
: available. Thanks in advance.-Greg