Varnishing temp


Beginner Canoeist
Hi All,

Here we go with another dumb question from a rookie. We finally finished painting our Old Town. I am waiting 5 days before flipping to varnish. If I don't spontaneously combust in this heat wave, I'd like to start varnishing (Epiphanes) the gunwhales, decks, and thwarts (doing a touch up/refresh for now). Is a temp range of high 80's, low/mid 90's going to be a factor? I realize high humidity will change dry time. Want to get it done so we can use it!

Thanks again!
Unfortunately, yes, temperatures in the high 80's to low 90's will be a factor. The primary factor may be the varnish drying to quickly which can cause a lack of flow in the applied varnish, perhaps exaggerated by using a heavy bodied varnish like Epiphanes. The other problem you might encounter would be the varnish surface drying in the high heat, but not through drying as quickly. This can cause the surface to wrinkle as it through dries creating a large sanding project to get it smooth again. Not sure where you are, it's supposed (?) to cool down by the end of the week if you can wait that long. Otherwise, you may be leaving yourself open to revarnishing at a later date...
Epiphanes does make a brushing thinner that you can add to make it a bit better in warm weather.

The next suggestion would be to varnish early in the morning.

I put a coat of varnish on a Willits this morning and it is going to get hot in the Chicago area today.

It does take a bit more time for the varnish to cure in this weather.

Good luck,


P.S. I did brush this coat on.


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We will be waiting until the weekend to do the varnishing. I did buy a can of the thinner with the varnish, guessing it will be put to use. Gathering that I'll have to be careful to not go to thick on the final coat.

Paul, your Willits is very nice! What woods am I seeing in it?
You are looking at the White Cedar "ribs", Mahogany thwarts, decks and gunnels with Sitka Spruce seats. Oh and White Oak king planks.

BTW the canoe belongs to Peter.

Good luck,

Finally have gotten a couple coats of Epiphanes on. We took note that when thinned, it seemed to flow out better, i.e. smoother finish vs 5% or less. 10% thinned seems to be optimal, humidity has been @50%. Any problem having the final coat thinned?

Thanks again for putting up with rookie questions.
Glad to hear it's going well for you. There is no problem thinning the last coat if it's working for you. However, remember that the thinner you add flashes off (evaporates) leaving you with a thinner dry film, meaning you'll have less varnish on the boat, less UV protection, and ultimately a shorter coating life before recoating. It's not a major problem, just something to keep in mind.