Yesterday, I varnished a new shop hanging cabinet... something to do during blazing summer that isn't too picky if I make some mistakes due to sweat dripping off every part of me.
It was super humid yesterday and actually the several nights before. A friend thought I was nuts. Maybe, but this is why I knew it would work out well.
For the first coat, I was wiping on a thinned varnish/oil mixture (Tried & True). Since I'm putting it on very thin, it seems to me that the atmospheric humidity plays much less a role in its drying than the moisture content of the wood. I'm in Arizona so the moisture content of the wood is typically single digit. Even after humid days, the surface of the wood isn't appreciably more moist, at least not enough to affect how the varnish flows and sets up. Despite the humidity, the first coat went on well and setup with no tackiness after 6-7 hours. I could have recoated, but left it overnight.
Today, equally humid. Now, if I were to put on another oil/varnish coat, the humidity will play a role since the first coat sealed the wood (taking it out of the equation) so now it is just the atmosphere setting the second coat.
But I want a second coat cuz I'm tired of this thing taking bench space plus the pile of things to go into it is getting equally annoying.
For the second coat, I need something that will dry regardless the atmosphere so I put on a thin coat of Epifanes' Matte varnish. The matte sheen is what I want (don't like '70s high-gloss plastic oak) and it happens that Epifanes accomplishes that sheen by adding Japan dryers. Others may, too, but I know Epifanes matte will dry -really- fast.
I applied a 50/50 Epifanes/mineral spirits mix in a very thin rubbed on coat. Honestly, when I worked my way to the right and finished the right side, the left was already dry to the touch with no tackiness. Likely not set enough for sanding between coats, but this went on so well that I would only need a quick pass with a Scotch Brite.
Naturally 'dry' and 'cure' are different and this will continue to cure long after I hang it on the wall (it is garage furniture). But it is nice to know that you can get one oil-enriched coat of varnish followed by possibly several matte coats in a couple days regardless the humidity forecast. That's a nice change from the usual 1 coat/1 day-or-more schedule varnish usually entails.