Professionals and Amateurs Together

Exterior Finish


What is the best applied finish for exterior wood surfaces such as doors, windows or boats (clear finish)?—Harvey Best


Peter Breu replies: Two part urethane finishes available in the marine market are extremely durable and offer UV protection as well. They are not cheap, but always remember the labor involved to redo a project once a finish has failed!
Richard Oedel replies: I have always used Spar Varnish on exterior surfaces, for bright work like boats. While it does require a lot of work to keep it looking bright, it is the only thing that I have found that works well. Epifanes is my preferred brand.

Bob Couch replies: I have had an opportunity to try a few different marine varnishes and the product that works the best for me and lasts the longest is Epifanes. It has worked very well for me on natural finished adirondack chairs, outdoor tables and other outdoor furniture projects. Epifanes is sold through West Marine ( and they offer great advice and provide information on the proper application of the product. The shelf life of these types of products once they have been opened is very limited. One of the nice things about Epifanes, is that they sell it in a 0.53 qt. size.

The product is very thick but flows out nicely leaving a nice high gloss finish that will be dry to touch and ready to re-coat in 24 hrs. For smaller areas, I have had very good luck with using a foam brush to apply it. For larger areas, you need a good quality brush designed for this type of finish. If you choose to spray it, you need to use a special thinner they supply.
For storage, I use a little Bloxygen in the can just before I seal the cover.

Bob Oswald replies: Two finishes stand out for outdoor use. Years of growing up in a marine world, we always use Spar Varnish on boat decks and woodwork. It’s designed for prolonged outdoor use, others are not. In reality however, nature is persistent and small cracks, etc. develop regardless, so it is an annual task to sand and refinish to keep the boat looking its best.
For furniture, etc, linseed oil is a reliable standby. House decks and patios have formulations at your lumber yard that hold up well. I have had high success with Penofin.

Tags: Finishing