?? Using Water based Poly over Tung Oil

[Gilbert Vega]

A friend of mind want to use WB poly on turnings that have a coat of Tung Oil blend. The Tung Oil brings out the grain so he uses it over all his turning. Would one expect any problems with the WB poly sticking to the oil based Tung Oil?

Gilbert

[Brian Kent]

Yes. Apply a thin coat of de-waxed shellac in between. It is the universal in-between coat.

[John Beaver]

Conventional wisdom says never put a water based finish over an oil based finish. Since the Tung Oil is probably an oil and varnish mix you will probably succeed if you put shellac in between, but I would test it on a scrap piece before I put it on a finished piece.

[Prashun Patel]

+1 on what Brian says. However, why the fascination with WB poly? An OB varnish will save you having to shellac.

[John Keeton]

Good advice from all, and I am in agreement with Prashun. Usually, the reason for using WB poly is to avoid an amber hue, but with using tung oil, that kind of negates any gain from the WB poly. If he wants a quick drying situation, then go with Generals Woodturners Finish - somewhat of an oil/water based hybrid that, in low humidity, will dry in 2-3 minutes. I just finished a small turning and by the time I made a complete coverage of the turning, it was dry enough for an additional coat.

[Gilbert Vega]

Thanks for the responses. My friend was primarily concerned about being green as well as having a quick drying time. I'll relay the info on the finish mentioned above.
Thanks again.
Gilbert

[dan fontaine]

Hello,

First post. I've used the WB over shellac over oil recipe. Just because I had them all on hand and was experimenting. Found that just WB over shellac looked good enough for me. Also noticed that the gain was simply cleanup time. 1 minute. Shellac brush is left to harden, brush or spray gun for WB is rinsed and that's it.

Dan

[Adrian Anguiano]

So why would the Water Based have issues with it being over the tung blend finish?

[dan fontaine]

Never really tried it. All I've heard over the years is how you might get adhesion problems. Although I do remember using and oil based stain under a WB topcoat. But only once the stain had thoroughly dried (2 days). And it worked fine. The oil stain was Minwax and the WB was from ML Campbell.