Hot coating varnish?

[Traveler]

So at the varnish stage on a 14 foot pack canoe I am finishing up (again). I actually thought I had this boat done last fall but had to do some major deconstruction and reconstruction (will post something on the whole, very sordid, story later).

I am using Helmsman spar urathane, and just put the first coat on. I am very tempted to go for three coats today, waiting for each one to be touch dry before applying the next, and without sanding in between.

Not worried about getting a furniture quality finish, but don‘t want to deal with a gummy mess either. I have read elsewhere of people doing this without a major mechanical problem, fine aesthetics be danged. Any thoughts or experience here?

Thanks
Tony

 

[Mike McCrea]

I have not put three coats of Helmsman Spar Urethane on in a day, but regularly do two, and still lightly sand in between.

But that is one coat early in the morning, and one just before bed, and usually on smaller pieces, thwarts, yoke and seat frames. And even those are hung in proximity to a radiant oil heater set on 600W low.

I do the same radiant oil heater trick when seal-coating or painting a canoe, even when doing just one coat a day. With a radiant oil heater set underneath the gunwales-down canoe the concavity of the hull nicely captures the warmth.

PB050012 by Mike McCrea, on Flickr

Even working off-season, without heating the entire shop, the temps may have been chilly overnight, but the hull was still nicely warm the next morning.

https://www.canoetripping.net/threads/project-boat-mad-river-independence.118819/#post-118942

Three coats in a day sound like a lot; but two should do-able with some added cure-heat. Then maybe some light sanding and a third coat the next day?

 

[Traveler]

Thanks Mike. This is on the canoe interior and gunwales. I have a couple of little electric heaters going under the canoe and temperatures in the garage are in the 75-80 range, so should be good.

I am putting the Helmsman on in very thin coats and it actually dries to the touch in a little more than an hour, which makes it hard to not just keep going. But I think it’s good advice to pause after 2 coats - this boat has already given me a lot of grief (all self-inflicted) and while I am itching to get it done I don’t want to pile on another mistake for the sake of one day. Thanks again

Tony

 

[yellowcanoe]

My varnishing skills are limited but under the watchful eye of a skilled boat builder learned to varnish early in the am and do something else during the day and sand right after dinner and apply another coat. That pretty much took up the 18 hours. He was not tolerant of sags runs or grabs.

So as we did five coats .. varnishing took the better part of three days.