Expert: Greg Scholl - 6/11/2011

Question
I turn bowls and vases on a lathe. I usually use just a Tung Oil finish on them and they look very nice. Lately I have used a Lacquer finish on some of them and they look good too. I am sure that I sprayed Tung Oil over one of my bowls that I put lacquer on. It looks really good. Question? Are these two finishes compatible or will the bowl have problems later like with peeling or cracking because I used both finishes?

Answer
Hi Gary, it really depends on a few variables...but ideally you don't want to use Tung oil over lacquer, but if the lacquer is thin and at least a few months old...it would likely be ok. I am a big fan of Generals Gel wipe on urethane topcoat, for it's very similar look to lacquer, (light straw color and excellent clarity),but exceedingly easy to apply and could be used over cured Tung oil for a little extra "pop" of the grain...it also can be applied with a cloth pad, while the lathe is spinning, although it does take a few hours to become 'tack' free....I use shellac a lot on turned items...it dries very quickly, allowing you to 'build' a nice deep finish quickly, it accentuates the grain and color beautifully, (I keep at least 3 types on hand at all times, Garnet, Blonde, and Super Blonde....all dewaxed flake that I mix fresh), and it can also be tinted with TransTints for a really custom color....and it is also food safe ( the other finishes are as well when thoroughly cured...) and can be repaired or refreshed easily and quickly. It isn't water resistant though like the urethane is, or another favorite of mine WaterLox...if you haven't used that, and you like Tung oils, you need to check that out!! I usually buy the dry shellac from Homestead or WoodCraft. Hope that helps a little...shellac is a wondrous thing, when you get to know it, most of us only learn about Orange shellac in our formative years...and there's so much more to know.......regards- Greg

http://www.waterlox.com/

http://www.woodcraft.com/Product/2005555/16556/Satin-Topcoat-Gel-Stain-Pint.aspx

And don't forget about the General stains also....:

http://www.woodcraft.com/family/2005555/2005555.aspx

http://www.woodcraft.com/Family/2020491/General-Finishes-Water-Based-Dyes-.aspx

http://www.woodcraft.com/Category/1004044/Shellacs.aspx

http://www.homesteadfinishingproducts.com/htdocs/shellac3.htm

Jeff's site is a fantastic resource, and he manufactures TransTint dye concentrates as well, a finishers secret weapon...spend some time on this site and bookmark it, and don't forget to check out the forums as well! And please purchase from him...we keep it there by supporting him.....

Yes, I meant  if the lacquer is not too thick, and it has cured for a few months...lacquer dries quickly, but like most finishes, does not fully cure for a few weeks to a few months.The typical lacquer application is  a sanding sealer coat followed by 2-3 coats of lacquer....this is cosidered a 'thicker' film finish... Long oils like Tung oil are essentially a varnish...with different characteristics, elasticity and hardness than lacquer, (depending on the lacquer),and are designed to be penetrating finishes, not a film finish that sits on top of the surface or another film finish... hence the concern with using it over lacquer. The Tung oil should also be applied in thin coats, with thorough drying in between...I was confused as to your application method for the Tung oil....but it should not be sprayed or applied over another harder finish as a general rule, and it takes several weeks to cure fully after the final coat. Sorry you decided to rate me as you did, as I feel my knowledge in this area is far above a '7', but you're entitled to your opinion...  and to finish anything the way you want....best- Greg