Dave Aukes
Curious about Wooden Canoes
Does anyone use, recommend or not recommend polyurethane varnish for canoe interior finishing?
Dave
Dave
Polyurethane Varnish
- Thread starter Dave Aukes
- Start date
pklonowski
Unrepentant Canoeist
"polyurethane" and "varnish" are two quite different finishes. On this forum, I suspect you'll find a vast majority preference for actual varnish, not poly.
Michael Grace
Lifetime Member
Hi Dave - Paul certainly speaks for me... traditional spar varnish! "Spar" varnish is so called because of its long use in the boating world, with "spar" referring to poles of sailing vessels - masts, booms and yards that support sails. Quality traditional spar varnishes are provide a more flexible finish and they contain substantial chemical shields that reduce the penetration and destructive effects of UV radiation. Polyurethanes are harder and resist scratching and abrasion, but this also means they are less flexible. Ultimately polyurethanes are more problematic in outdoor and especially aquatic environments that are subject to the effects of moisture, very high UV levels, dramatic temperature swings, and the shrinking and swelling of wood. They are more subject to failure as a finish and they are more difficult to rejuvenate, remove, and/or replace.
One more thing (more than what you asked for): quality spar varnishes made for boats can seem expensive (like $50-60 / quart), but they are well worth the cost. I have used most commercial marine spar varnishes, and personally prefer Epifanes products, but products from Interlux and Petit are also excellent. I haven't tried TotalBoat varnish yet, but I love other TotalBoat products and expect their varnish is excellent too. You can get off-the-shelf products at big box stores, but their solids content and UV shields may be lower. They tend to be thinner, so building up a good total varnish thickness will require more coats and much more labor, so I doubt the cost savings is real anyway.
Hope this helps.
One more thing (more than what you asked for): quality spar varnishes made for boats can seem expensive (like $50-60 / quart), but they are well worth the cost. I have used most commercial marine spar varnishes, and personally prefer Epifanes products, but products from Interlux and Petit are also excellent. I haven't tried TotalBoat varnish yet, but I love other TotalBoat products and expect their varnish is excellent too. You can get off-the-shelf products at big box stores, but their solids content and UV shields may be lower. They tend to be thinner, so building up a good total varnish thickness will require more coats and much more labor, so I doubt the cost savings is real anyway.
Hope this helps.
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Dave Aukes
Curious about Wooden Canoes
Okay, Good information, Thank You, Michael and Paul.
The bit about outdoor durability, ongoing maintenance, rejuvenation and replacement were my concerns.
The bit about outdoor durability, ongoing maintenance, rejuvenation and replacement were my concerns.
Dave Wermuth
Who hid my paddle?
For what it's worth...I always thought that spar varnish wore out from the top down whereas poly cracks and peels. What I recently discovered was a marine spar varnish by rustoleum, of all companies. It was a significant cost savings. However, it takes twice the amount to get a similar result. So, more time and money. the good stuff is better any way you look at it.
