water based varnish over BLO?

[Wade Lippman]

Can I put water based varnish over oil?
If so, how long does it have to "dry" first.

[Scott Holmes]

What exactly do you mean by water-based varnish? Sounds like a marketing guy got creative. Varnish is oil-based e.g MADE from oil.

Answer will depend on how you applied the BLO and how long you let it dry. If you flooded it on and did not wipe it dry with 15-20 minutes then you most likely have a soft sticky gunk on the surface. You'll need to get the surface dry and not the least bit sticky.

Then, a good option is to spray a light coat of de-waxed shellac aka Zinsser Seal Coat. Then you can top coat as you wish.

[Wade Lippman]

I've never used it, but I think it is pretty common.
http://www.woodcraft.com/Category/20...Varnishes.aspx

[Scott Holmes]

That's just Woodcraft saying varnishes note that the Enduro-Var says top coat not varnish.

It's a good waterborne finish. It is not varnish in the sense of varnish (oil-based) verses an acrylic 9water-borne)...

[John TenEyck]

Scott, varnish is generic; see below. You are correct that Oil Varnishes are Oil based, but there are other types of varnishes as well, such as Spirit Varnish and, yes, modern WB Varnishes.

John

varnish

noun
/ˈvɑrnɪʃ/




[uncountable, countable] a liquid that is painted onto wood, metal, etc. and that forms a hard, shiny, transparent surface when it is dry

var·nish

/ˈvärniSH/
Noun
Resin dissolved in a liquid for applying on wood, metal, or other materials to form a hard, clear, shiny surface when dry.

[Scott Holmes]

John,

We will need to "agree to disagree"...

Your WB "varnishes" don't cure, they are coalescing finishes. The acrylic in WB is already cured; an oil-based varnish will need to cure; about 30 day or so...

The WB's are emulsions; oil-based varnishes are molecular compounds.

They are different.

How clever of the manufactures to call some Water-Borne finishes varnish while others call it lacquer...
I'm pretty sure neither of us would use those terms interchangeably

FYI: Varnish is also the name of web application accelerator.

[glenn bradley]

I also think of varnish in the woodworking sense that it chemically cures as opposed to being left as a residue but, as stated, let's agree to disagree on "names". If the BLO is fully cured . . . what, maybe a few weeks in good weather and a well circulated environment if it was applied as described? I would then lay on a coat of de-waxed shellac for safety before top coating but, that's me. I hate wasting time stripping and refinishing so, when in doubt, I seal between dissimilar finishes. I know this is somewhat lazy from a chemistry-understanding point of view but, after putting hundreds of dollars of material and endless hours into a piece, I am more than willing to play it safe at the finishing stages. Exercising this paranoia, I haven't had to "fix" a finish in years ;-)

[John TenEyck]

Scott, of course you are correct about the differences in these finishes. I was only pointing out that the word "varnish" does not mean oil based. It is, surprisingly to me, a generic word. Therefore, the manufacturers are entitled to use that term for any product they choose, as far as I can tell. As users, we need to look under the hood to find out what they really are made of. And, as part of this forum, it would be helpful if we specify what product we are talking about - i.e. - oil based varnish, polyurethane varnish, WB acrylic.

John