Yes, you may apply tung wood oil on a walnut butcher block since it is non-toxic, food safe, and can create a protective even coat that can withstand moisture and water damage. Using tung oil on a walnut butcher block means supplying it with a good layer of water resistance.
We recommend using tung oil for walnut. This type of oil will darken the grain, enhancing and protecting the wood.
For a brushed-on finish, oil-based polyurethane is best. It is significantly more durable than water-based polyurethane for bar tops and restaurant tables because alcohol spills and the chemicals used for cleaning will soften water-based polyurethane over time.
Boiled linseed oil cures faster than tung oil, overnight in a warm room when all the excess is wiped off, as opposed to two or three days for tung oil. (Raw linseed oil cures much slower – weeks at a minimum – so raw linseed oil will remain sticky for a long time, even with the excess wiped off).
While there are many advantages to using it, pure tung oil takes two to three days to harden, and needs at least five coats. Oil/varnish blends and wiping varnishes are faster-drying, more practical options, but such terms rarely appear on labels. For help picking a finish, see below.
Applying tung oil is easy and effective! The main tips to remember are: don't leave excess oil on the surface during the curing phase, no sanding necessary between coats, no other sealer or topcoats needed and use 2 parts thinner to 1 part tung oil for maintenance.
Tung oil offers a number of advantages over linseed oil, including a food-safe, water-resistant finish that's not prone to mold and a beautiful matte amber color that doesn't darken over time. For your next project, give Pure Tung Oil products by the Real Milk Paint Co.
Walnut oil doesn't yellow over time the way linseed oil does, meaning truer colors. Walnut oil allows more pigment load than linseed oil, meaning colors with more tinting strength.
You can apply a wax on top of tung oil. You should not need to remove any of the existing tung oil to get an even shine.
When tung oil dries, it dries from the outside in. If there is too much tung oil left on the surface, or if the first coat is not allowed to cure before a subsequent coat is applied, there will be unreacted tung oil under the surface layer.
Any sort of "penetrating" oil such as tung or linseed needs to have the excess wiped off or it will (almost) never dry.
Pure Tung Oil will cure into a 'permanent' film unlike some other raw oil finishes. Permanent is in quotes because it will be worn away with use, cleaning, and exposure. Outdoor surfaces as well as heavily, or frequently used surfaces will need a touch up sooner than lightly used surfaces.
Tung oil hardens upon exposure to air (through polymerization), and the resulting coating is transparent and has a deep, almost wet look. Used mostly for finishing and protecting wood, after numerous coats, the finish can even look plastic-like. Related drying oils include linseed, safflower, poppy, and soybean oils.
Wipe-on poly or spar varnish will work on top of tung oil. This should protect the top from water damage, but it will show wear, so you will need to reapply every year or so.
To get maximum protection, you should apply 3 coats of full-strength tung oil. You should also have sanded with 0000 steel wool the day after applying each coat. As an optional step, you can use thin the first coat of tung oil by 50% or more using turpentine or naphtha.
It takes 24 to 72+ hours for Tung Oil to “dry” to the touch, depending on humidity and temperature conditions. Tung Oil should “dry” at least 72 hours before a top coat, such as a varnish, polyurethane, lacquer, or shellac, is applied over it. It takes approximately 40 days for Tung Oil to fully cure.
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.)
If you leave too much on the surface, or put on the coats too quickly, you run the risk of the tung oil developing a "frosty" look where some of the tung oil has turned white. The same thing would happen if you dried to add driers to tung oil.
After 24 hours of dry time, apply a second coat and allow the Tung Oil Finish to penetrate the surface for 5-10 minutes before buffing with a clean, lint free cloth. Two light coats are recommended for best appearance.
Mix one-part Pure Tung Oil to one-part Citrus Solvent. By mixing the two products, you boost the absorption of the oil into the wood. Sand your butcher block, up to 220 grit, to create an even surface for Pure Tung Oil application.
Tung oil characteristics
Tung oil is loved for the fact that it's “green,” and all natural, containing no VOCs. It offers a natural look and won't create a glossy one, and it won't darken or mold.
Tung oil is usually sold in satin, gloss or high gloss varieties. Follow the directions on the can. High gloss is possible with pure tung oil. The more coats you use the higher a sheen you will be able to achieve.