Tung oil is a favorite for finishing wood floors, cabinetry, decks, siding, furniture , guitars and other musical instruments, handmade toys, and more.
Oil finishes include boiled linseed oil , tung oil , and a mixture of varnish and one or both of these oils. All finishes that harden are film-building finishes. You can create a fairly smooth oil finish by sanding between coats using very fine grit sandpaper (#320 grit or finer).
You simply wipe on a thin coat, allow to dry, and rub in more coats, repeat till you are happy. Reapply over time as necessary. Every six months (or as needed) just dress the guitar with a light coat. It will continue to interact with the wood, and should last the life of the instrument.
Tung oil takes up to 48 hours to dry. Polyurethane dries faster than tung oil and takes only 12 hours to cure. Polyurethane sits on top of the wood to form a protective barrier that is watertight in only two coats. When considering tung oil versus polyurethane for wood floors, polyurethane wins the debate every time.
Woodworking Expert – Michael Dresdner: “Yes, I would put a coat or two of oil -based polyurethane on for more durability, and it is fully compatible over the dried tung oil (or linseed oil , or any other drying oil for that matter.) Add at least three coats, at one coat per day.
Tung oil finishes are usually applied to unfinished wood, but they can be used over oil based stains .
Drying oils, especially linseed oil (raw or boiled), are the only finishing materials that spontaneously combust . It’s not totally clear whether 100% tung oil can spontaneously combust , so treat it like it does. As linseed oil dries, it generates heat as a byproduct.
Tung oil definitely gets hard , but it doesn’t happen by evaporation. Chemists classify oils as “non- drying ”, “semi- drying ”, and “ drying ”. The word “ drying ” is misleading because the oils don’t really “ dry ” or evaporate; they “harden” or cure . The most commonly known drying oils in woodworking are tung and linseed oil .
Tung Oil has been around for many many years. It was used to preserve wood ships for hundreds of years. The oil penetrates into the wood , providing a relatively hard surface that repels water, giving it a waterproof finish. When tung oil is not thinned, in other words, it’s 100% tung oil , it’s a non-toxic finish.
Use fine steel wool to scrape up the softened tung oil . If this works and does not damage the wood, continue until the entire area is stripped. The harder the tung oil is, the harder it is going to be to remove. If solvents don’t work, your only other option is sandpaper and lots of hard work.
Ordinarily you would want the stain to soak into the wood . Tung oil seals the grain, so the stain would not penetrate.
Boiled linseed oil contains drying agents that let it cure overnight, but tung oil can take several days. Tung oil , however, darkens less with time. Oil /varnish mixes, such as Danish oil , enhance grain while laying down a thin film. Because of their oil content, oil / varnish mixes also need to dry overnight.