Author Topic: Tung oil question  (Read 1351 times)

Offline porchdog48

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Tung oil question
« on: August 07, 2019, 07:52:16 PM »

I am currently finishing a cherry stock with Woodcraft 100% tung oil, and really like the satin finish I am getting. Question is will the tung oil hold up to the  usual chemicals it will be exposed to such as oil, patch lube, and bore cleaners, or should I put a top coat of Tru oil or like product over it ?
  Dave

Offline Jason C

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Re: Tung oil question
« Reply #1 on: August 07, 2019, 08:26:45 PM »
Tru-oil will change the color some. I like to apply Johnson's paste wax over hand rubbed Tung oil and/or boiled linseed oil.

Offline Hungry Horse

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Re: Tung oil question
« Reply #2 on: August 07, 2019, 09:08:39 PM »
You have a nice satin finish because. Tongue oil never dries unless it has a driers added. True oil doesn’t seal the wood very well, and discolors with contact to black powder fowlings.

  Hungry Horse

Offline G_T

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Re: Tung oil question
« Reply #3 on: August 07, 2019, 10:51:45 PM »
?, you posibly mean Linseed Oil and possibly BLO never dries without driers?

https://www.realmilkpaint.com/blog/tutorials-videos/beginners-guide-pure-tung-oil/

Gerald

Offline Scota4570

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Re: Tung oil question
« Reply #4 on: August 08, 2019, 12:27:38 AM »
I have used tung oil finish with success.  It definitely dried.  Never tried 100% real tung oil, I have used lots of BLO.  Simmilar?  The deal with any finish is to not let it build up in the surface too much.  Some modern "bowling pin" finihses can be built up to a glass like coat.  They are not appropriate for a ML though.

I just  "finished" a piece of curly maple with slackum.  Slackum is equal parts turpentine, blo, and bee's wax. 

After using tannic acid and  AF.  I applied the slackum goop generously with a scotchbrite.  I melted it in with a heat gun letting it soak into the grain.  I let it cool and buffed it off.  It looks fine.  I can replenish it at any time.   

It seems to me that this kind of finish could have been used in the past.  I question whether the average backwoods gunsmith would have had fancy violin varnish finishes avail to him back then.  That is not to say the top end makers did not. 

What was the question...  : )

Oh yeah, will tung oil hold up?  Don't know.  You could spruce the stock up with the slackum mixture when ever you want.  I keep a large tin of it on hand for just such jobs. 

Offline bama

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Re: Tung oil question
« Reply #5 on: August 08, 2019, 12:58:42 AM »
Tung oil will do fine. Let it dry between coats and after the last coat, was with a good paste was. I think that a good waxing every couple of months adds a good moisture barrier, finish protection and makes the stock achive a nice warm appearance.
Jim Parker

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Offline smart dog

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Re: Tung oil question
« Reply #6 on: August 08, 2019, 01:08:22 AM »
Hi Dave,
You would be wise to use the search function and search for tung oil finish and polymerized tung oil.  You will find many posts over the years with all the information you could ever want.  Raw 100% tung oil is not a very good finish for gunstocks nor is 100% raw linseed oil.  They take months to dry and may never really cure.  Moreover, oil in the wood finishes are mostly a modern creation. Gun makers in the 18th and early 19th centuries used oil-varnishes mostly.  I use Sutherland Welles polymerized tung oil on my guns.  The oil is heat treated to speed up the polymerization (curing) and other solvents are added as well.  It usually dries to the touch in 4-6 hours and is ready for another coat in 24.  It cures within 3 weeks to a month depending on heat, humidity and exposure to UV light. Since you are already using 100% raw tung oil let me offer a suggestion based on my own experience. Go to your hardware store and buy a small can of polyurethane varnish.  Then mix your tung oil with the varnish as follows: 25% tung oil, 25% polyurethane, and 50% mineral spirits.  This mix will soak in giving an "in the wood oil" look or it can be built up to a higher gloss.  Better, it will dry to the touch in 12 hours and be ready for another coat in 24, and cures within 1 month.   

dave
"The main accomplishment of modern economics is to make astrology look good."

Offline Hungry Horse

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Re: Tung oil question
« Reply #7 on: August 08, 2019, 01:31:18 AM »
Tung oil will surface dry, but not down deep. The reason tung oil is satin when it dries is under magnification it is wrinkled.

  Hungry Horse

Offline G_T

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Re: Tung oil question
« Reply #8 on: August 08, 2019, 02:05:20 AM »
The surface gets first shot at the Oxygen in the air. So it dries faster.

In my experience with finishes, that usually means thin it more, apply lighter coats, improve ventilation, get temperature in the right range, and give more time (possibly much more time) to dry fully before adding another coat. Almost nothing that is going to use oxygen as part of the cure process is going to cure very well inside wood if the surface is saturated and essentially sealed before it gets a chance to cure on the inside.

Waxing soon after the last coat will also greatly retard the cure. Wax is a better barrier than most finishes. So best to save the wax until quite a bit later.

One can rush making something ready to finish. But rushing the finish itself never seems to work out well IMHO.

0.02c, primarily from finishing traditional bows with all sorts of finishes.

Gerald

Offline mountainman

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Re: Tung oil question
« Reply #9 on: August 08, 2019, 05:26:08 AM »
Thanks Smartdog for that tip! I have this bottle of pure tung oil,  and I wasn't sure what I was going to do with it once I was planning on using it in the future, I knew it had to be thinned down, but wasn't sure how I was going to do it.
Thanks again!

Offline smart dog

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Re: Tung oil question
« Reply #10 on: August 08, 2019, 02:40:40 PM »
Hi Mountainman,
I used that finish while living in Southeast Alaska.  I preferred polymerized tung oil but it was very expensive and took a long time to get because it had to be barged from Seattle not flown in.  I could get raw tung oil, polyurethane from local hardware stores and mineral spirits. So I improvised (as always) to create a finish that looked HC and stood up to the very harsh weather and salt air that my guns lived in. It worked very well and behaves much like Tru-Oil and Permalyn. However, it does not have that plastic look like Permalyn when built up on the surface (if desired).

dave   
"The main accomplishment of modern economics is to make astrology look good."

Offline porchdog48

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Re: Tung oil question
« Reply #11 on: August 08, 2019, 09:13:18 PM »

I have been thinning the tung oil with 50% mineral spirits, applying, and then hanging outside in the sun. This usually takes 2 days to dry. I then rub stock down with extra fine scotch brite , and start the process over. My original question was how does it hold up to patch lubes , bore cleaner, and general cleaning solvents?
Dave.

Offline Daryl

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Re: Tung oil question
« Reply #12 on: August 08, 2019, 11:55:19 PM »
This one is true oil - done in 1986- I'll give it a few more years and see if that will discolour it some.
Close to, or over 4,000 shots through her, about 1/3rd were 165gr. 2F. Maybe I need to use more powder
to get more fouling to get that powder fouling/discolouring of the True Oil happening???
 






Daryl

"a gun without hammers is like a spaniel without ears" King George V