Does varnish settle/separate over time?

[Lew's Canoes]

I am in the process of restoring a 30's era OT Yankee, and having a problem I have not experienced before. I have 4 coats of varnish on the interior - early coats thinned, last two nearly full strength - and I am getting a very uneven, blotchy finish. Most of the hull has a beautiful, smooth, even varnish coating, but there are a significant number of spots that have no gloss, and have taken 4-5 days to dry. The shop is heated and the good areas dried overnight, as expected. I am certain that the condition of the underlying wood was uniform, clean and dry, so I do not think that is the problem. I am suspecting a problem with the varnish - it is Pettit Captains #1015, which I have used succcessfully for years. However, the particular can I grabbed for this job had been sitting on my shelf for several years, unopened, and I am wondering if the contents had settled or separated, such that I had a 'out-of-spec' mixture when I poured about 1/3 of the contents from the can. I did not stir the contents before using, other than stirring in the thinner for the early coats. Anyone ever had such a problem, or care to suggest a course of action? Thanks, Lew

 

[Gil Cramer]

I believe that your analysis is correct. Varnish has dryers, solvents, and other stuff in them which are likely to settle over time. To solve the immediate problem, I would likely grab a purple Scotchbrite pad, moisten it with paint thinner, and go over the entire canoe rather vigorously. After everything dried which might take more than a day, I would re-varnish with varnish from a fresh can. I would save the suspect varnish for the hull exterior making certain to stir it vigorously before using. Since I'm not too good at following directions, I always stir varnish. I've even been known to shake it. Gil

 

[Jan Bloom]

Varnish does not settle and separate like paint. It gels and when that happens it is basically ruined. You can try thinning but it will rarely dry as well as good fresh varnish. If it is gelled below the thickened leathery skin that frequently forms on the surface then dispose of it and buy fresh new varnish.