Thinning Varnish Question

I'm ready to start varnishing and have read conflicting reports on thinning varnish prior to application. I've purchased the Interlux Schooner varnish from CLC and intend on rolling the 1st coat on and then tipping out using a high quality brush. My question is this: Is it necessary to thin the varnish first or is it okay to apply it directly from the can?

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RE: Thinning Varnish Question

I think if you read "When to Varnish" a few posts down from this one, you'll get all the answers to your questions I think. Good luck, I'm gonna be starting in a few days to.


RE: Thinning Varnish Question

On my varnished boats I went with the instructions in the CLC Shop Tip The Varnished Kayak. I saw John Harris demonstrate this at Okoumefest some years ago. The kayak already had a base coat of varnish on it and had been mostly wet-sanded. John started with a demonstration of wet sanding by finishing that job. Next he opened a can of Schooner varnish, poured out a few ounces into a jar and closed the can. Then, while continuing the patter, he proceeded to varnish the bottom & sides of the kayak using the varnish in the jar.

The job took 20 minutes or so, used only 1 cheapo foam brush, no rollers, no thinners and looked great when he was done. It was simplicity itself.

That last point is important. For some reason, builders get weird when it gets to varnish time (maybe the fumes?) and they come up with all sorts of bizarre techniques and recipes for the perfect finish. It's sort of like those chile cook-offs. For your first kayak,I'd say avoid the chili chefs and just stick with the Shop Tips.

Have fun,




RE: Thinning Varnish Question


Thanks for the input. I did a test run on one of the hatch covers I'd cut out. I simply hand sanded using 120, 220 and 400 grit emery paper and then laid down one coat of straight varnish using a chip brush. It looks great! I'm ditching the chili chefs and taking my chances on simplicity...




RE: Thinning Varnish Question

I followed the CLC method last summer on a CH17LT and it came out fine with relatively little trouble. But when I was varnishing my Shearwater beginning of a fairly cool December, things didn't seem to go as well. I was using the same Interlux Schooner varnish, (from different, fresh cans) but it didn't want to cover as smoothly as the job I did in July. That is what brought me to fooling around with adding some Brushing Liquid 333 (Interlux recommended thinner for Schooner varnish). I think that the varnish I got in December was thicker and didn't want to level as well. I don't know if my trouble was related to a quality control problem with the varnish (probably a little) or difference in ambient temperatures (definitely some), but my guess is that some adjustment may be necessary just due to variation in different batches of varnish. So, I had to get a little weird to do that second job, but it wasn't out of any particular desire to get weird.

Also barring some clever hack with inert gasses, or very careful opening and resealing of the can, the varnish will get a little thicker and lose some of its volatile components over the week or two it takes to put on 5 or 6 coats. The thinner can help to counteract that effect too.

 Question: So now I have a few cans of Schooner varnish that were opened last year, (resealed) with various remaining amounts. How well would that varnish still work next winter if it was consolidated and possibly thinned a little? Or put another way, what is the useful shelf life of an opened can?

 Aside: The forum software here is getting so slow, that I find myself frequently wandering off to look at videos of cats being ridiculous, while waiting for it to respond. Once I start watching the funny kitties, I often forget that I had clicked on something over here expecting that it would, like, respond or something? Perhaps the forum software could use a little Brushing Liquid 333 to loosen it up a little? Or maybe its just me that needs the 333.



RE: Thinning Varnish Question

Interlux 2333N thinner made my Perfection varnish flow out and self level reducing brush marks to zero without it the varnish is too thick to do that by itself. I think people get wierd around varnish because everything sticks to the wet surface and at that point in the build they are so sick of sanding. On my first coat I had a small 1' sq window open and it was blowing some fresh air in the area so I left it while the varnish dryed when I came back hours later something had landed on the finish making it look and feel like a nonskid surface. It turned out to be lint from a roll of TP. After sanding it off all coats after that the window and door was shut.

I wouldn't bother with a roller the foam brush alone does the job fast and is self tipping.

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