Renew Your Canoe Using Urethane
Teflon Antifouling Boat Bottom Paint
Turbulence eats up energy and can slow down your canoe. It has been known
for a long time that a 2-inch scratch on a smooth surface can generate
turbulence for 10 or 12 inches as water flows over the scratch. If you
have an older canoe, its bottom is probably no longer smooth.
Fairing your canoe bottom is not that difficult and can be done in a few hours
with simple hand tools and under $50 in materials. First use a 100-grit
sanding sponge or palm sander with purple 3M-type paper to clean the
bottom.
Then get out the glazing compound. You can find it at
www.boat-bottom-paint.com for $4.98 a tub. You will need one or two tubs
for an older canoe. Use the plastic putty knife that comes with the
glazing compound right out of the tub with no mixing and fill in all your
nicks on the bottom. The glazing does not need to be perfectly flat
because it sands easily to flush it up with the existing canoe bottom.
Allow the glaze to harden for about 1 hour and sand off with a sponge or
palm sander. Then repeat until the bottom is smooth.
Next seal the canoe bottom. You want to use a great non-stick coating like
that used on cookware. Cookware coatings are based on the largest molecule
known, one that has a lower drag coefficient than ice. This type of
coating was first developed by DuPont and marketed under the name Teflon.
A good choice is Smooth Sailing Boat Bottom Urethane Teflon Paint which
comes in three colors.
Use blue tape to mask off the water line. Then mix the urethane and
hardener 3 parts A to 1 part B hardener and apply with a 4-inch mohair
1/4" nap roller. A good technique is to just pour a little urethane on the
bottom and then wet the roller, spreading the urethane out as thin as
possible. By the time you get to the end of the canoe, you probably can
start over with your second coat. If you see some bubbles as you go, just
roller over again to break them.
After two coats (about 400 cc of material), let it harden for 5 hours,
sand off problems, and do your final coat. If drips over the
mask or on the side of the canoe occur, just wipe off with thinner while the
urethane is still wet. Note that you should get your final coat on within
10 hours of the first coat to assure good adhesion. If you get any orange
peel or if the bottom is not as smooth as you like, get out that wax
orbital buffer and some light rubbing compound to smooth down to that
perfect glass finish. |
Click images
to enlarge
Original surface
First glaze
After sanding
First coat
Second glaze
Final result
|
