Just curious if I can leak proof the outside of my newly built and stained boat with a coat of epoxy and several coats of varnish?

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Comment by Richard Elder on April 19, 2013 at 6:49am

Eric,

Rebecca Wittman--- now there is a name out of the past!  When I was living on the Cape George sailboat that I posted a picture of recently, she was working on a varnish job on the boat in the next slip. Mentioned that she was writing the definitive bible about vanishing and would like to bring a photographer down to photograph my boat and feature it in the book.  Then she asked what flavor of varnish I used.  When I told her I didn't rely on only varnish, but coated it with AwlGrip high solids clear for durability she choked and gasped and went running down the dock. (LOL) Don't know if she ever went back to finish her job on the neighbor boat.

Since my boat was then five years along with about 10 hours per year maintenance, I guess the system I used would have been bad for business if you are a professional boat varnisher.  Moral of the story is never trust somebody who compares varnish to fine wine---.

Comment by Eric Loudenslager on April 16, 2013 at 8:07pm
According to Rebecca Wittman - The brightwork compansion - (page 31) varnish, oil (boat soup), and sealer all consist of similar Oil, Resin, and Solvent. Varnish has less oil and more resin than "oil" finish, sealer has oil, resin, and solvent in that order in larger quantities.

So varnish and oil, and oil stains, are all made of the same basic ingredients, and therefore largely compatible...but not always. They are also in the same class as alkyd paints...epiphanes, interlux, petit.

Epoxy resin is in a class by itself. If would is saturated with oil, the epoxy doesn't stick as well. Epoxy sticks better to wood than polyester resin, which is why wood-composite boats are built with fiberglass saturated with epoxy resin. Molded fiberglass boats like Claka and Hyde are made with polyester resin and chopped glass blown into a mold.

Some waterbased top finishes can be applied over oil stains if they are dried long enough.

Wittman argues throughout her book that exterior (also interior for a db) should be varnished, rather than oiled. Her logic is that the prep of oil and varnish is the same, and takes most of the time. Oil will last only a few weeks and needs to be reapplied at least every month. Varnish on the other hand should last a year.

My canoes with oiled ash gunnels rotted because I didn't keep up with the maintenance schedule. I have varnished the replacement set....hopefully the varnished gunnels will last longer.

Many folks on woodenboatpeople oil river dories. Nothing wrong with that, but realize the pluses and minuses of the various options. My stitch and glue dory is painted inside and out, with bright finished deck, gunnels, and interior seats. The bright wood is epoxy sealed and then varnished. When I recoat later this spring I'm going to use General Finishes Exterior 450 waterbased varnish. In the past I used Interlux schooner. I am trying to get away from solvent based coatings.
Comment by Josh Bizzle on April 16, 2013 at 5:08am
What I can't understand is how spar varnish will stick to oil stain but epoxy resin will not.
Comment by chris towles on April 15, 2013 at 3:21pm
Never Unfortunatly. Now that the oil has penetrated the wood nothing is gonna make epoxy stick. Your options at this point are lots more oil, or oil based paint after a good healthy sanding. Glass and epoxy won't stick now.

It's not the end of the world, oil works and has worked for hundreds of years. You just need to be conscious of keeping the boat dry, storing it someplace where it's covered, and keeping water from pooling in the boat. Just oil it often and it should provide you years of trouble free service.
Comment by Josh Bizzle on April 15, 2013 at 11:04am
Well the stain is an oil based stain, how long would you say wait before I do or can epoxy?
Comment by Rick Finnell on April 15, 2013 at 11:01am

If the stain was water base yes if oil no.

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