What type of solvent to thin Spar Varnish?

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Forum topic by gdemo posted 12-28-2009 03:48 PM 6652 views 0 times favorited 4 replies Add to Favorites Watch
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46 posts in 2732 days

12-28-2009 03:48 PM

Topic tags/keywords: spar varnish finish solvent ratio

I use Spar varnish for most of my finishing. My question is what would be the best solvent to thin it with for the first few coats? And what would be the best ratio of thining? Any help will be appreciated! Thanks, gdemo

-- I ams what I ams and thats all that I ams...(Popye!)

4 replies so far

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#1 posted 12-28-2009 03:52 PM

try mineral spirits 20 %

-- david - only thru kindness can this world be whole . If we don't succeed we run the risk of failure. Dan Quayle

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46 posts in 2732 days

#2 posted 12-28-2009 09:17 PM

I have seen mentioned on other sites that for the first coat you should go 50/50 does that sound logical to you?

-- I ams what I ams and thats all that I ams...(Popye!)

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1381 posts in 3551 days

#3 posted 12-28-2009 09:47 PM

Spar varnish is a generic term.
The formulations can vary.

Which brand?

The types of wood and/or projects you are finishing can also effect the amount of solvent used for thinning.

What kind(s) of wood and/or project(s)?

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#4 posted 10-19-2011 01:12 AM

Just would like to share an experience I had today. I’m applying a second coat of semi-gloss spar varnish to a small surface and was trying to stretch out the end of the can, which was getting a trifle thick, so I added a small amount of a product now being sold as a substitute for mineral spirits in California (which can;t be sold anymore it seems), an acetone- petroleum distillate mix called simply “all purpose thinner.” I’d say the ratio was perhaps five or six varnish to 1 thinner, and a small amount at that. Within a couple hours, the varnish was unusually dry and had a buttery matte finish. Something in the thinner affected the varnish adversely. I’m going to have to wait for it to dry thoroughly, sand it down, and apply a new coat of new varnish. Anyway, it seems this is a bad mix for spar varnish.
I see there is another thread with this same topic, and I may share this experience on that thread as well, in case somebody on one of the threads has some input back to me on this. I hope this doesn’t drive anybody crazy.

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