Varnish (McCloskey) Says, "Do Not Thin"

[Cram]

I'm making shelves out of some beautiful tiger striped maple and have them ready for finish work. I have been trying different finishes on some maple scraps I have in the shop. I bought Jeff Jewett's "Great Wood Finishes" and want to try mixing up a good varnish to finish the shelves with.

From his book - "The best all around finish I've found is 1 cup of

varnish, 1/3 cup of linseed oil and 1 cup of naphtha (which dries more quickly than mineral spirits)."

Now, there is good info on how long oil or spar varnish should be used for exterior work as it will expand and contract with the wood and that for interior use short oil varnish should be used as it is a harder finish. Additionally, manufacturers do not indicate the ratios of the oil content specifically, but will show whether it is indoor or exterior.

I've searched three different stores in the area (Southern NH) and only found spar (long oil) varnish on the shelves. I finally remembered Rockeller is a store I go to sometimes for other wood working supplies so I stopped by there just now and noticed McCloskey Heirloom Oil Base Varnish.

When I got home I read the back more completely and noticed that twice in the instructions & other info - "Do Not Thin"

Why would they have this written on the back? As I understand it Varnish is Varnish and it can be thinned for whatever we want to apply. Is there something unique about this brand?

This is the first project of this level in quality I have created so I want to make sure I am doing things correctly. With the trim work and other carpentry I do, poly was good enough and was what I used mostly.

[Greg Esres]

Most or all say that. From what I understand, it's there merely to make sure the VOC levels are within legal limits when sold. You may thin the product as you see fit.

[Cram]

That's what I figured when I first saw it. Shortly after I posted this I made the varnish mix and it's set to dry on a test peice right now. I'll put another coat on in the morning to be sure how it appears to be working and then likely move to my work peice. Seeing your reply confirms my suspiscion.

It kinda threw me though. I've not mixed for my finish work ever before and wondered if I was missing anything.

Thanks for the reply Greg.

Marc

Greg Esres wrote:

[bridgerfafc]

if the varnish is anything but high gloss, make sure you stir thoroughly before taking part of the contents of the can for thinning as the flattening agent will settle to the bottom of the can. the varnish will still work but the gloss won't be what you expected. for the same reason, shake your mix frequently while using.

[Dave W]

[Cram]

By the way - this project is coming out nicely... I did start with the mixture mentioned in my initial post and put the first coat on and when it was dry I sanded, wiped and I'm at the point of watching the second coat dry. Well, I'm doing other things with my days besides watching it dry, but you get the point.

It's really bringing out the waves in the maple. Can't wait to see this one up on the wall.