Varnish or Polyurethane?

paul heller · Post by **paul heller** » Thu Apr 16, 2009 1:02 pm

I'm building a door and a rudder for a sailboat. Both are out of Mahogany. Most of the time, the door will be on and exposed to the weather (especially a lot of sun) and the rudder will be stored inside the cabin (where it is dry and out of the sun). But when sailing, the door will be stored in the cabin and the rudder will be attached to the boat and actually submerged in the water.

When I made a rudder 30 some years ago. I used varnish. That rudder held up very well for a long time.

I'm curious what you would advise? Outdoor polyurethane, or spar varnish? Or something else? I can't seem to find varnish locally. I guess I would have to buy it online somewhere. Any recommendations what brand of polyurethane or varnish would be best for this type of application?

Thanks.

Paul

charlese · Post by **charlese** » Thu Apr 16, 2009 2:17 pm

Good Morning, Paul! Since I have absolutely no experience with any of my home made furniture under water

, I will suggest you go with what has worked for you in the past. In my experience, spar varnish it is pretty tough stuff.

At the opposite end of the water spectrum, we used spar varnish to keep and maintain our showshoes that were worn daily. Actually every other day. We had to own two pair, and alternated them daily. Needed a day and night for the new coat of spar varnish to dry. We varnished every morning while waiting for the Sun to come up.

You would be surprised to find how abrasive snow is! We had to varnish to keep the leather webs from soaking up and stretching. Icy snow would even wear away at the wood frame, especially at the toe.

tom_k/mo · Post by **tom_k/mo** » Thu Apr 16, 2009 2:22 pm

Paul, I had good luck with Deft Spar Varnish on a finished wood/steel glider I finished years ago. Held up well.

Gene Howe · Post by **Gene Howe** » Thu Apr 16, 2009 2:38 pm

I use a spar varnish called Man O War on all projects exposed to weather and sun. Very tough.

8iowa · Post by **8iowa** » Thu Apr 16, 2009 4:59 pm

I used to have a sailboat in the hot South Florida sun. You are going to need a marine spar varnish with UV inhibitors. Take a look at the various V-Spar products.

mbcabinetmaker · Post by **mbcabinetmaker** » Thu Apr 16, 2009 10:11 pm

Paul

Use a marine varnish and I believe the Man O War mentioned in another reply is one name brand of such.

Thanks
Mark

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Varnish or Polyurethane?

Varnish or Polyurethane?

Marine Varnish