Pure Tung Oil Finish

[FlinterNick]

Anyone Ever use 100% pure Tung Oil as a finish ? If so, do you wet sand ? What is the drying time between coats ?

 

[Old Hawkeye]

Not a good plan to use any "pure oil finish". Whether it is tung, linseed or some other oil it needs to have some drying & hardening agents or it may never dry properly depending on your climate & storing conditions. Tung is also susceptible to mold if not properly dried. Mix in some Venetian turpentine, some spirit of turpentine, some Carnuba wax or other hardener/dryers to get a good usable finish.

 

[Zonie]

I have a can of "Pure Tung Oil" that I bought years ago to use on gunstocks.
It was only after I tried using it that I realized it was indeed "pure" and it didn't even become tacky until it had been on the wood for about a week.
It didn't have any dryers in it and it "dryed" just about like pure linseed oil does.

While on the subject of tung oil, a number of years ago, the military tried switching from linseed oil on their wood stocked guns to tung oil. When the guns were released to the troops, suddenly several people became sick. It was only then that the fact that some people are very allergic to tung oil. With this new finding, the military went back to using linseed oil on their wood stocked guns.

 

[SDSmlf]

If you decide to use Tung oil, make sure it is Tung oil. Most of the so called Tung oil finishes have just a splash of actual Tung oil in them.

I use Tung Oil from Real Milk Paint.
100% Pure Tung Oil Wood Finish & Protection - Non-Toxic Wood Oil
I cut the Tung Oil 50%-75% with mineral spirts (I use Stoddard solvent, not the odorless stuff WallyWorld sells) to help it penetrate the wood. The multiple coat process I use takes 4-6 weeks to fully cure. I do not sand between coats nor apply any wax. Maybe once a year or so I wipe down the wood with the Tung Oil mineral spirts mix if the gun has been exposed to harsh elements or the wood is scratched up. While outside what we discuss here, I have Milsurp stocks, some 100 years old plus, finished this way that are really abused in competitive shoots (rain, snow, mud, lubricants, very hot barrels, etc), whose finishes hold up extremely well, at least in my opinion.

Here is a photograph of TC stock finished with Tung Oil 10-15 years ago. It has seen a lot of time in the woods and on the range. Any scratches, nicks or dings are covered with light touch up coats every so often and just add to the stock’s character

There is concern that some people may be allergic to Tung oil, as the US military decided years ago to stop using it because of than concern. Tung oil, by the way, comes from the seeds of tree’s fruit (like the seed in a peach pit for example), and are not nuts. In a British study of people with tree nut allergies, none were found to have a reaction to refined Tung oil. A Canadian study found the risk of allergy to Tung oil to be about 0.1% of the population.

 

[Flintandsteel]

Unfortunately, no builder can make a living using a finish that takes 4to 6 weeks to dry.
Hence the reason driers were added to make it into a oil varnish. Couple coats a day vs a coat A month.

 

[dave_person]

Hi Nick,
As others wrote, pure raw tung or linseed oil are not great finishes by themselves. They need some agent to speed drying and curing. There are several choices. Tung oil that has been heat treated or "polymerized" is my current finish of choice. I use Sutherland -Welles polymerized tung oil. Years ago, when I could not get SW, I mixed raw tung oil with polyurethane varnish. That was an excellent finish and the varnish additive dried the mixture quickly. An oil-varnish (of some sort) is a good mix. The third strategy is to add a drier like Japan drier to the oil in the same way painters dried raw linseed oil.

dave

 

[SDSmlf]

Unfortunately, no builder can make a living using a finish that takes 4to 6 weeks to dry.
Hence the reason driers were added to make it into a oil varnish. Couple coats a day vs a coat A month.

Don’t know where you got the coat a month from. For the Tung oil process I use, I start with at 50% or more mix of Stoddard solvent (mineral spirts) with pure Tung oil. I apply a generous coat and let the stock sit for 30 minutes or so, then wipe ‘dry’ with a rag. Note, be careful with how you dispose of any Tung oil soaked rags, they will spontaneously combust. I will repeat the about process every hour or so, until the wood doesn’t seem to be absorbing any more Tung oil, up to four or five times the first day. Each coat takes but a few minutes to apply, and the wiped down goes quick. The following day I’ll repeat with one or two coats. I’ll skip adding any coats on day three, then apply one or two coats on day four. If the finish looks good the next day, I’m finished, just have to let it full cure, which takes three to four weeks, though you can handle the stock well before that. Also learned not to put the stock out in the sun before cured, or some of the oil will bubble up onto the surface.

I have finished numerous stocks with this process and find it to be a durable and forgiving finish. It doesn’t blister or chip like some poly coats when scratched. You just apply a bit more Tung oil to the damaged area and it will blend right in, adds to the wood’s character. I started using Tung oil on Milsurp stocks that are up to 100 years old or so. These are competition guns that get used and abused in all types of weather. At times from rapid firing and the hot sun the wooden forearms get too hot to hold. The Tung oil finish comes through unscathed.

 

[SDSmlf]

Hi Nick,
As others wrote, pure raw tung or linseed oil are not great finishes by themselves. They need some agent to speed drying and curing. There are several choices. Tung oil that has been heat treated or "polymerized" is my current finish of choice. I use Sutherland -Welles polymerized tung oil. Years ago, when I could not get SW, I mixed raw tung oil with polyurethane varnish. That was an excellent finish and the varnish additive dried the mixture quickly. An oil-varnish (of some sort) is a good mix. The third strategy is to add a drier like Japan drier to the oil in the same way painters dried raw linseed oil.

dave

Dave

I was typing and didn’t notice your post until after I posted. A little surprised by your reservations about using pure Tung oil. I used the stuff from Real Milk Paint for years now and love it. Maybe used on 30 plus stocks. Did our oak kitchen table top about two years ago and the finish has held up remarkably well. Took four or five days to apply the Tung oil, then let it partially cure for just over a week before bring it back into ‘light duty’ service while the curing process completed.

Not a Kosher topic for here, so I’ll try and be careful, but below is a photograph of a partial Milsurp gunstock originally made in 1917. It was cut down right at the band (there was no wood to the right of the band on the bottom piece of wood) before I owned it. I found a donor piece of similar grained walnut from a gun made in the 1920s and spliced the two together to make the stock full length again, with the splice seam under the band. With some creative finishing and aging ended up with a pretty good match. I then applied Tung as described in my earlier post and the gun as since become one of my match guns. The wood has been through a lot post finishing. It has laid on wet ground, mud and snow. It has spent hours in the rain. It has been blistering hot because of use and sunshine and held in my dirty, sweaty hands for untold hours during use since finished years ago. Have not retouched the finish since. For clarity, the wood above the seam or split running the length of the gun is two separate pieces, while the wood below is the ‘one piece’ that has been spliced.

 

[Stevey30]

So I have done a couple of stocks, these were for myself not to sell. My old gunsmith buddy told me years ago the proper technique, a coat a day for a week, next a coat a week for one month, finally a coat a month for 12 months. I know this is almost impossible, but you should see the finish when you are done. I did very light sanding between each coat, they shine and water just beads off of them. Again not practical but I was not in a hurry when finishing them and 23 coats should long outlast me.

 

[alfaguyml]

Polymerized tung oil dries and looks great. The stuff is expensive, but it is all I use on muzzleloaders now.

 

[philipgill]

Yes, 100% pure Tung Oil can be used as a finish. Wet sanding is typically not necessary. The drying time between coats varies but generally ranges from 24 to 48 hours, depending on environmental conditions and application thickness.

 

[oldwood]

Raw tung oil is one of the worst liquids to put on a gun stock. Did that once 50 yrs. ago , hunted in the rain , by the end of the day , finish was 90% gone. Bad idea. Polymerized tung oil is good for a penetrating first coat or two on raw wood.

 

[FlinterNick]

Raw tung oil is one of the worst liquids to put on a gun stock. Did that once 50 yrs. ago , hunted in the rain , by the end of the day , finish was 90% gone. Bad idea. Polymerized tung oil is good for a penetrating first coat or two on raw wood.

Raw Tung Oil by itself is very difficult to finish a stock with.

I’ve used Milk Paint Raw Tung Oil, but I’ve had to mix in Japan Drier and Spirits to get it to dry correctly. So I ended up making varnish from what i intended to be an organic finish. Kinda defeated the purpose of buying it.

The grain can be worked no further than 180 for it to dry correctly and absorb, 220 is pushing it.

It ended up looking really nice, but the results were no more better than using a polymerizing varnish such as Tru-Oil or another other varnish.