If you're like me and love to turn but not overly love the finishing process, this finishing process may be your answer. First, and yes most important, you must prepare your project for the finish with the various stages of sanding until your satisfied with the surface of your project. After the sanding is complete, I apply 2 coats of Deft Lacquer Sanding Sealer, with a buffing of 000 steel wool after each coat. Then I use Formby's Tung Oil Finish (I prefer the High Gloss Finish) with a cloth lint free rag, let dry at least 12 hours, lightly steel wool again and give it another coat. When dry, it looks like glass. By the way, I got the Formby's at Walmart for about 5 bucks for a pint which should finish many projects, and the Deft at Woodcraft for about 7 bucks.
================================== Stemo, I don't want to rain on your parade, but the process yopu describe defeats the real benefit of the tung oil - a penetrating finish. Use of the sanding sealer prevents the penetration of the tung oil, and also prevents the color enhancement that the tung oil can provide. The sanding sealer will "pop" the grain some, but not like tung oil or danish oil will. You might want to try reversing your application and see if doesn't improve the appearance.
1) Formby's Tung Oil Finish has no actual Tung Oil in it. It's a thinned Varnish (wiping varnish aka a polyurethane/oil formulation) with just a touch of boiled linseed oil (BLO) in it.
2) Yep, the lacquer sanding sealer (just thinned lacquer that you can make yourself and cheaper that way too) will interfere with the penetration of the Formby's which, basically, negates the use of it especially because...
3) The Varnish (basically just a polyurethane) and the lacquer don't get along well. You'll likely have adherence problems between the two. The only thing saving your application (at least at this early stage) is the fact that you scruffed the surface of the lacquer before applying the Formby's. You'll still likely get separation. It would be even worse if you'd reverse the application with the Varnish underneath and the lacquer on top. Polyurethane (and it's offspring Varnish) adheres mainly by mechanical means. This is why you must give it a slightly scuffed surface for it to bind to between coats. Lacquer binds chemically (with other finishes/paints/itself/etc). No need to provide a scuffed surface. This is also why lacquer evens out much better than the Polyurethanes.
So, if you apply the lacquer over the varnish, there's nothing in the varnish for the lacquer to chemically bind to.
I'm sure you have a nice looking surface, Stemo. Let's just hope it stays that way.
A small change to your process is to just use a gloss lacquer finish in place of the Formby's. If you want an incredibly glassy finish, very lightly wet sand (800+ grit) between each coat or two of the gloss lacquer for a few coats. You're not providing a binding surface for the next lacquer coat, mind you. You're knocking down the high spots in the finish and giving a uniform reflective surface instead of those high spots reflecting light off in different directions. This is often called the Piano Finish procedure. I've used it pretty successfully with black lacquer many times before to give that deep wet look.
==================================== I guess I must be getting too trusting in my old age. I just assumed that because the name said "tung oil", that's probably what it was!! The procedure you describe is the same that custom auto painters use to get that "foot deep" lacquer finish on show cars. On some wood surfaces, you'll get some grain ripples over time that might not show up as much on a less glossy surface, but it will still look good.
I really don't know much about lacquers, beyond using them on our cars back in the Sixties. Do they have inherent UV resistance? Can successive coats be applied without sanding? Anything you can tell me would be appreciated.
Regardless of what your nose thinks, George, and what the wood finish manufacturer advertises, we found no actual Tung Oil in our tests. The ingredients in a wood finish are only "regulated" as it pertains to health/safety. Formby's can't say that they "meet or exceed Low-VOC levels" for this product because of it for example. Nowhere in those "regulations" do they have to completely and specifically (or terribly accurately) tell you what is in there unless it falls into some FDA, EPA, OSHA, etc. lists. Tung Oil doesn't fall into those lists. They can tell you anything they want in that case.
I don't rely on advertising, especially in the wood finishing business. I test it.
As compared to what? To nothing at all, then yes. Lacquers with pigments have more of a UV resistance and then you can buy lacquers with actual UV protectants in them. Don't expect miracles though. It's not going to save your Purpleheart, Osage Orange, or Padauk from going dark/brown but it'll slow it down to varying degrees.
"Can successive coats be applied without sanding?"
Absolutely. That's one of the nice things about lacquer. It binds to itself chemically and doesn't need that rough surface in order to bind. That's why it levels (bumps, grooves, brush marks, etc.) itself so well as compared to the polyurethanes. There's really no layers of coating. They all become one.
The sanding I was referring to in my previous post wasn't to help in binding each coat to the last. It's just to give a deeper, higher gloss shine.
I recall attending a presentation by Bob Flexner a few years ago and he commented that there was no tung oil in this product. Granted, that was a few years ago and the mfgr could have changed formualtions, but I believe that at one time, the statement is correct.
"Maxprop" wrote: (clip)Can successive coats (of lacquer) be applied without sanding? (clip) ^^^^^^^^^^ Lacquer dries by evaoration of the solvent, without any crosslinking of the molecules. The dry film is soluble in lacquer thiner, so if another coat is applied, the surface softens, and bonds well to the new coat. Sanding is good only to smooth out the imperfections and remove particles of dust, but does very little to improve the bond.
The other finish that behaves like this is shellac, BTW.
********************************** Lacquer, if shot from a spray gun, is usually thinned down from it's "in the can" consistency, so it results in a very thin layer. On auto applications, you can shoot 2-3 coats, then block sand with 600-800 wet/dry to level imperfections, the repeat until you have the desired effect. It's not required as far as adhesion is concerned, because each coat disolves into the previous layer. As far as UV, you can add inhibitors to clear. Most of the larger book stores have custom auto painting books, and they have really good sections on how to use all the different types of film type finishes, lacquers, enamels, epoxies, catalyzed, acrylics, etc. A good investment IMHO.
The results ARE entirely the point. It's not the immediate results I'm terribly concerned about nor was commenting on. Like I told the original poster, I'm sure he's getting great looking results ... for now. And I'm not looking into the future 30 - 50 years from now either! Lacquer and Polyurethane don't mix. That's just Finishing Basics. The chemistry detail is an appeasement for those that can't take advice without some scientific justification or a bibliography attached.
"AHilton" wrote: (clip) Polyurethane don't mix. (clip) ^^^^^^^^^^^ I recall from the days when I was a paint dealer, that polyurethane had a problem with adhesion to itself, because it dries so hard. So, if the recoating was done more than a day later, sanding was especially important. Urethanes also dislike sealers containing stearates (soaps). But, once a lacquer film is dry, I do not recall any special reason why urethane would not adhere (to a properly sanded surface.)
There is often confusion due to the fact that lacquers act like paint remover over oil based paints and varnishes. In that sense, I can see that lacquer and urethane do not mix. Even there, however, if very thin coats of lacquer are misted on, allowing the film to build up while releasing the solvent, it is possible to create a barrier which will allow the lacquer to adhere and not damage the undercoat.
Does any of this jibe with your understanding? Have things changed since I learned about it, or is my memory slipping.
Being a sailor and 'mechanically-bonded' to varnish myself, I haven't had any experience with lacquers. Thanks for the info. Sounds like interesting stuff, and something I'll spend some time with.
Thanks to you, too, Ken. Your post recalls some lacquer paintwork we did on my cousin's Austin Healey 3000 quite a few years back. We generally made the surface smooth and imperfection-free with primer (from 6-9 coats, with
800 wet sanding between), then shot four coats of colored lacquer followed by 4 more coats of clear. We rubbed out the colored coats, but not the clear. Not sure if the clear had UV-inhibitors, but the paint is still on the car and it looks great today.
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