Tung Oil Finish Practicality from Sawmill Creek
Fairly new to the hobby, a woodworker asked if a friend was getting the straight story from a cabinetmaker. The professional advised that the only correct finish for a cherry TV cabinet/armoire would be a tung oil - a la Thomas Moser - and that it would have to be refinished on a periodic basis. The pro even claimed that some people send their furniture back to Mr. Moser for re-oiling! Up to this point the questioning woodworker's finishing experience had been with boiled linseed oil, polyurethane, and shellac, and he wondered if others went with tung oil, and if so, was the maintenance DIY!

As to the connection with Thomas Moser, another poster quickly dispelled that notion by quoting Mr. Moser's FAQ for a heated linseed oil-and-wax finish that reveals the grain pattern and ages gracefully. It also included instructions for customers to maintain the finish themselves with no need to send the piece back. The poster also agreed that tung oil was a feasible finish, but that some people wouldn't care for the smell when it's re-applied. He also noted that it could be over-varnished in the future, although that would probably void the craftsman's warranty.

A couple of posts suggested telling the cabinetmaker his finish was simply unacceptable and having him explain his reason for the approach, or having him change it, or finding a new craftsman! After all, noted a supporting post, there are 1,001 ways to finish furniture!

In response to his question on DIY … yes, a post noted, tung oil is easy to apply … but only as needed and not according to a strict schedule. Another respondent described raw tung oil as a penetrating oil (like raw linseed oil) that doesn't make a surface film and may never really dry. There's also a form of cooked (polymerized) tung oil that leaves a very thin film that he likes, provided the piece won't be exposed to water. And finally there are "tung oils" applied by brush that may contain other resins like polyurethane and make thicker films. Re-applying the latter finish wouldn't accomplish much, and the second coat might not even bond.

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In fact, the validity of the term "tung oil" in some finishes was called into question after a woodworker recounted using at least four coats of Formby's "Tung Oil Finish" on a curly cherry end table and his satisfaction with the low maintenance results. Au contraire, replied another finisher, the aforementioned "tung oil finish" was simply a marketing term for a tung-oil-like finish and may or may not actually contain any real tung oil. Some, he claimed, are mixtures of varnish, boiled linseed oil, and mineral spirits (e.g., Deft Danish Oil, Minwax Tung Oil Finish, Velvit Oil, Watco Danish Oil). Other "tung oil finishes" are made from varnish and mineral spirits and sold as a "wiping varnish." Unlike the above mixture, these finishes are not wiped off, and are slightly more protective. They include Formby's Tung Oil Finish, Zar Wipe-on Tung Oil, Waterlox, and Jasco Tung Oil, among others. His distinctions were made in the name of accuracy and did not indicate relative quality.

Back to basics, another woodworker recalled an old saying about pure oil finishes never being finished! Some people, he noted, deal with this by applying wax over the old, but then they have to clean and re-wax the finish periodically. His solution is to start with mostly pure tung oil (and thinner) for the first coats, then gradually add polyurethane to the mix to build coats. Towards the end, his mix is 1/3 each: tung oil, thinner, polyurethane. Then he might add a couple of coats of thinned polyurethane. His trick is to not add too much each time and to let it cure between coats.

To avoid the blotches that sometimes come with finishing cherry, the same poster suggests using dyes instead of stain. Another forum member counseled flooding the surface with solvent, or partially sealing the surface with shellac, glue size, or a commercial pre-stain conditioner before applying oil. He finished his cherry by wiping on a mixture of boiled linseed oil, tung oil, and turpentine (in a 1:1:2 ratio) and immediately wiping it off. Then he applied a few coats of a naturally colored shellac (garnet, kushmi, lemon, etc), followed by the topcoat of shellac, lacquer, or varnish.