Polyurethane on Sunfish tillers and rudders?


The 2015 thread on Sunfish Restoration by Alan Glos came up recently. I have a follow up question.

I’m in the process of restoring 8 wooden Sunfish tillers and a rudder. I have stripped the old varnish or paint off of the wood tillers and have sanded them with decreasing coarseness of sandpaper, as suggested. Our club’s Director has a preference of Polyurethane over Varnish, can anyone suggest a Polyurethane product for tillers that will be stored in the North Carolina sun and weather for 8 or 9 months a year. Our Lake Norman is a freshwater lake.

I've had luck with Minwax Helmsman Spar Urethan. It seems to last a fairly long time.

There are also 2 part post cat spray urethanes that are high build. ML Campbell has one. Most auto paint suppliers can hook you up with an automotive one that works great on wood too.
FYI, the 2 part automotive spray urethanes require full protection to use even while stirring. I have done antique car restoration and sprayed a couple of gallons by this point.

The urethane paints have, in addition to the solvents that kill the liver and kidneys, isocyanates. This chemicals cause an allergic reaction. The first time you might feel some tightness in your chest. With each exposure the symptoms get worse until you get what is call industrial asthema (probably not spelled correct).

I talked to a researcher about the paints. Basically he said the number one exposure was during mixing because people are not fully covered. The pros are usually fully covered when spraying to prevent lint on the paint. Plus they use a pressure fed air supply.

If you chose to use those paints make sure you have a lot of air flow and away from other people. It is easy to under estimate the danger from this type of paint.
you could also drop the parts off at a finishing/woodworking shop or almost anyplace that does auto body work..the automotive urethanes are way more expensive than the furniture stuff. You'll get a really nice finish that way and you won't have to deal with it.

You can also get that minwax in a rattle can but I don't find it lasts on exterior stuff as long as a decent spar varnish. It also doesn't build. Pettit flagship and brushing thinner for the win.


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Thanks danpal, joe, and shorefun for your inputs. I’ve decided on the Minwax Helmsman Indoor/outdoor spar urethane, I think that a quart is more than enough for three coats.

I’ll be applying it outdoors, and because of the warnings I will be especially cautious to avoid breathing the fumes, because of using it outdoors I won’t worry too much about the health issues. Outdoors does however create other hazards such as airborne dust, bugs, leaf litter, etc. I can accept those possible drawbacks.

The Minwax website lists quite a few suggestions for this product such as: “Ideal for use on doors, windows, trim, bathroom cabinets, bar tops, kitchen countertops, outdoor furniture”. They don’t mention boats, which I find to be odd considering the words “spar” and “helmsman” in the name of their product.

The Lowe’s (hardware store) website describes this product as an oil-based varnish. Minwax doesn’t use “varnish” in their description.
You'll be fine.. The exposure issues are really more for regular exposure with significant duration. And anything you get from the box stores won't have anywhere the risks of material that's being commercially applied. So you'll be totally fine.

.I've used it on white oak garage doors that I didn't want to spend a bunch of money on with finish hoping it would weather nicely. Because I wanted some ebonizing streaks from the cast steel hardware etc..it definitely weathered. The good thing is you're doing it on small items so refinishing won't be a big deal again in a few seasons. That rattle can is also available from lowes etc.

Once it's cured up you can treat it like brightwork..imperfections can be wet sanded and if you get sags you can cut them off with a straight edge razor.

Have fun.
I like the Minwax products. For rudders and daggerboards I like Minwax Gloss Spar Urethane applied with a 4" foam roller followed by a foam brush (so called 'roll and tip' method.) Sand/steelwool between coats. Three coats are usually enough. Wear gloves and eye protection. Good ventelation is always a must.

Alan Glos
Cazenovia, NY
Minwax also offers Polyshades which includes a stain, available in different colors. We have found this useful in evening out the finish of rudders and daggerboards that have blemishes from previous water damage, or for darkening lighter wood like ash and spruce. Here is 2 coats of Polyshades Cherry on spruce, for a double paddle we just made.


And polyurethane paint sticks well to polyurethane finishes. In case you want to color code the blades to the boat :)


I was thinking that a cover might be a good idea after watching a few YouTube tutorials and critiques of Urethane. Sun damage appears to be a drawback to Urethane. One of our club members who helps out with boat upkeep can sew and offered to help make a dozen or so covers. Has anyone made a tiller cover (or anything else) out of a retired Sunfish mainsail? (Our club’s Flying Scot boats use a Sunbrella-like fabric as a tiller cover.)
Update: I have refinished 7 tillers. Some had a coat of cream-white paint over the original varnish. The rest had bare wood among the places where the varnish remained. All were stripped with a chemical paint remover by brushing it on and then scraping it off. All were then sanded with a 60 grit, 100 grit, 160 grit, then finally with a 220 grit sandpaper.
I used Minwax Helmsman oil-base Urethane, matte finish. The first two coats were diluted by the addition of mineral spirits, about 10% of the weight of the urethane. The last two coats were full strength urethane. I lightly sanded the tillers between coats, after drying for at least 24 hours, with 220 grit sandpaper. I did not sand the last coat, it looks good and feels good with the hands.

The before photo is after the final sanding, before application of urethane. The other photo is after all coats.