Gel Varnish over Oil finish

[William Hamilton]

I was at a very well-known furniture design studio recently and asked them their finishing technique. They said they used Cabot #8099 Tung Oil Finish, wiped on for several coats, lightly sanding between coats with 0000 steel wool to remove dust nibs, and next, they wiped on Bartley's Gel varnish. After that they buffed out the finish. Does using gel varnish over a finish like Cabot's Tung Oil Finish sound like a good idea? I was under the impression that Cabot's tung oil was actually a finish that would build up, so putting a gel varnish over it seemed redundant to me. They achieved great results however. Any thoughts on this? Thank you.

[Prashun Patel]

I've used Cabot's tung oil finish before. You're right. It's varnish over varnish. Some people like to use a thinner, wiping varnish like the Cabots as a sealer because it's thin and they believe it penetrates. Personally, the only reason I see to use it for the first coats is color (the Cabot tung is about as dark as Waterlox OSF) and workability. You can apply it quick and liberally. Applying a gel varnish for the first coat can take marginally more time than a wiping varnish.

The reason to switch to a gel varnish for the final coats is to speed the build. But if you're don't need much build and you have a couple extra days to apply more coats, you can do fine with the Cabot TOF.

Caveat: last time I used this was about 4 years ago. I am uncertain if they have reformulated it to be low VOC, which might change my vote about whether to use it for the final coats. I know Cabots has reformulated their Spar varnish in the past couple years which has made it harder to work with than I was used to.

[Howard Acheson]

Applied as instructed on the label, Cabot Tung Oil Finish does not produce a built up film. The product is absorbed into the wood leaving the look and feel of and oiled finish.

Gel varnish is just a varnish that has had thickeners added along with a drier. It contains solids that will build to a film finish. The furniture maker could just as easily applied a coat of oil based varnish but the jell varnish is rubbed on leaves a nicer looking finish in the opinion of some folks.

[Prashun Patel]

When I used it, it behaved more like a wiping varnish than an oil varnish. It created a hard film.