Frequently Asked Questions
General FAQ
Tung Oil is a non-edible vegetable oil with oxidizing or curing properties making it suitable as a wood finishing oil.
In short, it’s cooked Tung Oil. We heat process our raw Tung Oil to its “maximum thermal threshold”, which makes the Tung Oil more sensitive to oxygen. It will cure (harden) faster with a minimal addition of chemical driers. It’s also more durable as the polymerization process gives the cooked Tung Oil hardness when cured and it also increases the sheen.
Raw Tung Oil is a VERY SLOW drying oil. It takes upwards of 6 weeks for raw Tung oil to cure and often remains sticky during that 6 weeks.
Yes, it can be used on any porous stone, unglazed tile, and metalworks. It is best to use any relevant Sealer (check products for best usage) and fewer coats will be needed.
Yes, ALL of our finishes are considered inert and food safe after they are full cured for 30 days, except our Millie’s All Purpose Penetrating Tung Oil. Millie’s finish is the quickest to reach food safety usage, as it is formulated with Polymerized Tung Oil, Citrus solvent, and beeswax with no added driers making it usable once DRY, usually after just 3 days. This is great finish for salad bowls, cutting boards, and counters such as a kitchen island to be used as food prep.
Yes, the only difference is the UV and Mildecide additives between the two. They are fine to use indoors.
To Clean: Clean using Sutherland Welles wood cleaner OR 1 cup vinegar or ammonia to one-gallon warm water and soft, clean cloth. Do not use any cleaner with a SOAP base (Murphy’s oil soap/bona etc.) under any circumstances, they will leave a film that will gum up the surface of the oil. Do not use a steam cleaner.
To Refresh:Apply Sutherland Welles Tung Oil polish and buff with a clean dry cloth.
To re-coat:Scuff lightly with fine steel wool, sandpaper or pad. Re-apply finish.
Sutherland Welles is invested in the life of your finish. Give us a call or email us sales@tungoilfinish.com to ensure your success with our finishes. 1.800.322.1245
Using Our Products
Ideal conditions are a temperature range of 55-77F (room temp is best), with humidity less than 65%, within those parameters our finishes will be dry to re-coat in 24 hrs. Whenever you finish in conditions out of these recommended ranges you may need to allow for longer curing times.
Push your finger-tips against the grain of the wood. If they glide easily over the surface-you are ready to apply your next coat. If there is any grab or friction felt, you will want to give it more time. To help you know what that feels like, just glide your finger-tips over a piece of furniture you own and feel how they slip across the surface. That’s what you’re looking for prior to re-coating.
For your first coat you will get about 600 square feet out of a gallon. This could be less if the wood is porous and thirsty. 800 for the 2nd coat, and 1000 for all other coats. These numbers work for most species of wood. Use division to find out how much finish you will need for each coat and add all the coats together.
Example If you have 500 square feet.
Coat 1: 500/600= .83.
Coat 2: 500/800= .62.
Coat 3: 500/1000= .5.
Coat 4: 500/1000=.5.
Add them up and you’ll need 2.45 gallons for 4 coats. Order 2 gallons and 2 quarts or 3 gallons for future touch ups.
A natural White China Bristle brush (stainer-style, square tip) is best to use to apply our finishes, especially the film finishes in the Murdoch’s line. This brush is available on our online store. A short-napped, synthetic floor pad can be used for large floors. A Scotts blue shop towel can be used for small tight areas. It can also be sprayed using a HVLP sprayer to a achieve a light thin coating.
Yes, you can if there is a scratch or blemish on the finish. Sometimes wiping our Polymerized Tung Oil over a scratch will make them disappear and blend in. Blemishes or marks in the surface layer of finish will need to be removed by lightly sanding with fine sandpaper first. Sometimes the entire board will need to be refinished to have it blend in or the entire surface of a countertop or table.
If you choose to, we recommend using carnauba wax a week after the last coat is applied. Keep in mind that wax has a tendency to “halo” or leave rings on a dining room table under hot drinks/food. It will also need to be removed before any recoating can occur. We suggest not using wax on dining tables, counters, or coffee tables if wet drinks will be placed there. Sutherland Welles does have a Tung Oil Polish that is a great alternate to paste wax. It can be used as extra protection and as maintenance.
With the exception of our Exterior line of products, any unopened can of our finish is good forever.
The most reliable way to store residual finish is to use our StopLoss bags available on our website. Other methods are to use a product like Bloxygen, which is a spray of Nitrogen gas that puts a gas layer on the oil to protect the finish from oxygen in the partially full can. You can clean the can inner rim of the can well so the plug seats uniformly and firmly in place and store it inverted- not advised for Exterior products. You can also pour it into a smaller container (metal or glass) leaving little air space- make sure to label it properly. Marbles or clean rocks can also be dropped in to take up the airspace.
Troubleshooting FAQ
Too much finish is being applied. Use less finish on your brush and move the finish to make a very thin coat.
You will need to lightly sand them away. Usually, a light sanding with sand paper – 600 grit will remove them. If that doesn’t work, switch to the next coarser grit of sandpaper using even pressure across the entire surface. Wipe the dust off with a dampened cloth with mineral spirits to see if they gone and before applying more finish.
This usually only happens when using a wiping technique with the first couple of coats. It’s known as speckling or bleed back, which is when the oils seeps back out of the wood and cures causing small spots or dots. Typically, this happens on open grain woods like Oak and Walnut and most often with the first couple of coats if they are being wiped. The friction of wiping speeds up the evaporation of the solvent in the finishes and makes the Polymerized Tung Oil very thin and it migrates to the surface as the solvent gases off. It can be avoided by not wiping you first coat. Apply a thin layer and let it soak into the wood and cure. This almost always will eliminate these spots from happening in the first place.
See above for how to keep that from happening. It’s important to deal with them as soon as you notice them. They aren’t going to disappear with adding another coat.! Sand the surface lightly with 440 grit sand paper. Wipe the surface down with mineral spirits on a cloth. Let dry and observe the surface. If it’s a large surface area, but not all areas have the spots, you should still sand the entire surface. You can’t spot sand and have the end result be uniform.
This is called streaking and flashing. This happens when a prior coat of finish didn’t dry properly before another coat was applied. Moisture is trapped under the surface of the finish creating the streaks. This will need to be sanded back down to that layer and allowed to dry and re-coated.
Two- part epoxy. You can take it a step further and mix sanding dust with the epoxy before filling. You can also purchase tinted epoxy or dyes to add to epoxy to match or highlight the voids.
This only happens in a partially full can that has been used. If the finish is thick and gel-like, the finish has oxidized in the can. You can attempt to thin it down by adding mineral spirits or our Di-Citrusol and stirring it gently to see if you can coax it back into solution. You may need to pass it through a fine paint strainer to remove any small globs.