: A friend has recruited me to glass a canoe his son started sone ten or so
: years ago. He finished the stripping and sanding, (and did a damned good
: job of it) then he sealed the wood with shelac prior to glassing with poly
: resin. Am I correct in assuming that this needs to be sanded off prior to
: using epoxy? It is no big deal since the son will do the sanding, and my
: thoughts tell me that the epoxy will get a better bond to the wood if the
: shelac is sanded off. Thanks for any advice.

In the days before epoxy resin was so common, strip built boats were made from white cedar, not red cedar, and covered with polyester resin and glass cloth. apparently the red cedar was just oily enough to cause problems with polyester resin bonding directly to it. That was not the case with White cedar.

Red cedar is easier to come by, particularly in long lengths, so it has apparently become the wood of choice for strip built boats, and epoxy resin has been dragged into use because it bonds so well to Red cedar.

There was, however, a "workaround". If the boat was built from red cedar and it was coated with a layer of lacquer then the wood would be sealed and the polyester resin would work. I had not heard of using shellac, but I suspect that was the reason it was used. As long as so much work has already been done you might want to jsut finish up with polyester resin. The material has a lot of advantages: You'll save a bit on cost, it is a bit thicker so runs are fewer, you can put on second and third coats in the same day, and it is much more resistant to UV light, so varnish is not even needed. Instead of sanding each year and putting on a few coats of varnish, you can wait several years. After 10 or 15 years of use you can sand off the old glass and recoat with epoxy, polyester, or whatever new material has been invented in the interim.

Just a thought.

PGJ