Tung Oil Refinishing Technique

I have cultivated a stock refinishing technique that a few comrades have expressed interest in after seeing the end results. The technique utilizes Tung oil and I am happy to share it with you now.

First off the method I am about to explain is probably not what the original rifle builders used when finishing stocks. It takes a little time but the resulting finish will be smoother and have a bit more luster than the original. In my opinion it is by and large a very pleasing satin finish.

Please note that in this article I am not going to discuss cleaning the cosmoline out of an old stock, but you should try and get as much oil out of the stock as possible prior to proceeding. Unfortunately I don’t think it is possible to get all of the oil out because fifty or more years gives the stuff ample time to take set. Even if you scrub away like a Viking your stock will most likely still have discolored spots.

I have found that sanding is very important to a good refinishing job. You do not want to go overboard to the point that you sand off cartouches and other arsenal marks but at the same time you want to take out as many dings and discolored areas as possible.

I start off with a 100-grit paper and work with a sanding block. The 100-grit will remove a lot of excess surface oil and discoloration without removing too much wood.

Next I sand with 220-grit paper. 220 grit is very forgiving and allows you to smooth the wood nicely. After you have finished with the 220 there will still be visible dings and dark areas remaining. It takes some work but you can raise dings and dents by laying a damp cloth over the wood and applying a couple passes of a clothes iron.

Dark spots: A gunsmith once imparted to me that you can apply bleach with a Q-tip to lighten the the dark areas, but it didn’t work for me. Maybe I was too impatient. I decided to use a wood darkening technique instead and see what happened.

It seems that no matter how hard you try there are always a couple gouges that still need to be filled. A mixture of sawdust with Elmer’s glue making a paste works great as a filler. Please note that when dried the filler will be darker than the wood but later steps will alleviate this problem.

Everything I have told you so far goes out the window if you are dealing with a laminated stock. The laminated wood is very tough and difficult to sand and dings do not steam out easily. Sometimes it is just a good idea to leave the dark spots and tell yourself that they add character.

Let us assume that you have a de-oiled, sanded, filled, and otherwise prepared stock and are ready for finishing.

The first thing to do is to give the wood a good washing with denatured alcohol and let it dry for several hours.

In order to apply my method of finishing with Tung oil you will need the following:

1) Half-pint container of Tung oil. I personally like Formby’s low gloss Tung oil finish.
2) Mineral spirits. Low-odor stuff is nice.
3) Small paintbrush. I use a 3/8” artist’s brush. You want a quality brush that will not shed bristles.
4) Oil based stain (more on this later).
5) 220-grit wet/dry garnet paper.
6) 400-grit wet/dry garnet paper (optional).
7) 600-grit wet/dry garnet paper (optional)
8) Roll of blue (lint-free) shop towels.
9) Rubber or vinyl gloves.

Now you are ready to finish the wood. Using my darkening method with Tung oil there are three steps to the process.

The steps are sealing, filling, and finishing.

Step One: Sealing

You need to seal your stock to keep moisture out. You can do this by mixing one tablespoon of Tung oil with three tablespoons (i.e. 3 to 1) of mineral spirits. This is a thin mix but you want to get the oil DEEP into the wood and the thin consistency aids this process. Paint it on and let the wood soak it up. Use special care to get the mix into all the screw holes and exposed wood surfaces. I usually only use one coat but several will not hurt. Let the sealing coat (s) dry for at least 24 hours.

Helpful Tip: When done painting on your sealer coat simply wrap your paintbrush in a baggie and put it in the freezer. It will last a long time and you will be able to use it repeatedly.

By now you will notice that the wood has darkened considerably. It is now time to take “stock” of things and decide whether you want to stain your stock or leave it as is.

Step One ˝: To Stain or Not to Stain

If you are working with a laminated stock you probably do not want to stain as the laminated wood does not accept the stain too easily. The picture below of the Kar 98 German Mauser shows the end result of a plain-oil finish. It also shows the imperfections in the laminated wood. All in all I was very satisfied with the end result.
 

Finished Kar 98 German Mauser

If you are dealing with a non-laminated stock consider what type of wood you are dealing with. The wood used for rifle stocks is usually very dense and you will want to use a dark stain to have an adequate final result. I wound up flipping a coin in the hardware store because I could not decide between dark mahogany and dark walnut. Mahogany won the toss so I picked up a small can of Minwax (oil based) dark mahogany stain.

Walnut stains nicely, but teak (as on a Yugo SKS) is a little more difficult to stain. Teak seems to require more applications of stain and is a bit frustrating as the wood tends to soak the stain up like a sponge.
 

Yugo SKS

If you decide not to use stain just ignore the word “stain” from this point on.

Stain, Stain, Stain, Stain, and Stain (are you ingoing it?)

Step Two: Filling and Staining

Now that your stock has been sealed with oil, its surface will feel somewhat rough. If you want to make your stock smooth and add some color you will need to fill the grain. To do this you will need wet-dry garnet paper and an oil/stain mix.

Take a sheet of 220-grit garnet and cut a bunch of one-inch squares (larger if you have catcher-mitt hands & sausage fingers). Next mix your filler oil. I use one teaspoon of stain, one teaspoon of Tung oil, and thin the mixture with two teaspoons of mineral spirits.

Set yourself up with your garnet paper, stock (don’t forget the handguard), oil mix, and a blue shop towel. Dip a piece of the garnet in the oil/stain mix and begin lightly sanding the stuff into your stock. Work in small circles and and only work a small area of the stock at a time. Complete all the areas of the stock that will be visible after you reassemble the rifle. With a little practice you will get the feel for how hard to bear down on the paper.

After you have sanded an area and before the oil mix dries take your shop towel and lightly wipe diagonal to the grain. Again, it takes a little practice to get this just right. What happens is that you have created an oil/stain/sawdust slurry with your sanding, and you are now wiping it into the wood and filling the pores.

After you have finished, set the wood aside to dry for a couple days. You should notice that your stock has now become more uniform in color.
 

Yugo M-48A stock (without the barreled action) illustrates the result of one application of oil and mahogany stain.

 

Finished M-48A stock

I generally repeat this sanding/wiping application with the stain/oil mix one more time. With the teak stock on my Yugo SKS I used four applications to get the desired color.

After the stock is the color you want you can either go on to finish the wood or you can continue the filling process with finer grit garnet paper. Using finer paper will create a very smooth finish. Some folks do not want such smoothness on a rifle stock that was never smooth to begin with. If that is the case, go on to the section on finishing.

For those who want a smooth stock, repeat the filling procedure above with 400-grit paper. When you make your oil mix leave out the stain. Apply a couple coats with the wet-sanding and wiping technique. If you really want the smoothest finish possible finish off with a couple more applications, this time using 600-grit garnet. The truly hardcore and demented could go on to 800 grit, but I have never gone that far.

Step 3: Finishing

Now that your stock is filled, you need to protect it. This is where hand-rubbing comes in. Actually, it is more like “finger-rubbing,” the way I do it.

Mix a 3-to-1 oil/mineral spirits mix as before, but be advised that you will not need much mixture. You will see what I mean the first time you do this and can use your own judgment when mixing future batches.

What you do here is dip your finger in the oil and rub it into the wood in circles. Rub a small area at a time until the oil takes a haze, then wipe WITH the grain with your ever-present blue shop towel. This time, you want to put some pressure on the towel. Wipe firmly. When you finish, let the stock dry for at least a day. Two days is even better.

The rest is up to you. You should apply at least four hand rubbed coats to protect your stock, but you will get more luster and shine with each additional coat. In the pictures, the Yugo SKS has 6 coats, the Kar 98 has 12, and the Mosin Nagant has 17.

Note how the Mosin Nagant has the nice red hue that is the trademark of the original finish.

After you rub in your last coat, you can either leave the stock as-is or rub in some wax after the finish has cured. I have never used wax, but I am guessing that you want the oil to cure for at least 2 weeks before waxing. You also want to avoid letting your stock bake in direct sunlight for at least a month.

Note on safety and Tung oil storage

Denatured alcohol, mineral spirits, and Tung oil all contain chemicals that can do bad things to your body if you inhale them in or absorb them through your hide. I always wear disposable rubber or vinyl gloves when using these chemicals.

For finger rubbing I take a disposable vinyl glove and cut the fingers off. That way I can do five applications with one glove by using a cut-off finger as a “finger cot.”

Tung oil will deteriorate the more it is exposed to oxygen. If your oil turns into a gel, throw it out, as it is ruined. This is why I advise buying a half-pint of Tung oil. When I started, I bought a pint can, thinking that it would last for years. It turned to gel after finishing only three stocks.

There are a couple methods to make your oil last longer. What I did was to gather some pebbles and wash them. Then I dropped them into the bottle of oil (after they were completely dry, of course) to keep the oil level up and keep the airspace to a minimum. Marbles would work well too. NEVER leave the top off the container any longer than absolutely necessary.

I also noticed that Brownell’s carries a product which is basically an aerosol can full of heavier-than-air gasses. What you do is spray some into your oil container before screwing the cap on to expel any oxygen.  Seems like a neat product.....but rocks are free.

Darren Locke