Woodworking Talk banner

1 - 10 of 10 Posts

·
Registered
Joined
·
187 Posts
Discussion Starter #1
Hey guys, I'm trying to figure out which finish I want so I did a test on some scrap and out of the three listed they all look the same. Just wondering if after multiple coats they start to darken or differ from one another. Here is my test piece with one coat. They are in order the way their lined up. I'm finishing a maple and red oak box. Was going to stain the red oak walnut and the maple top with teak,blo or tung.they just all look the same to me.

image-4213120218.jpg
 

·
Registered
Joined
·
3,473 Posts
Over time, the linseed oil will get darker than the tung oil. According to the MSDS, the Watco is linseed oil, though I thought it had tung oil in it also, or at least used to. The Behlen Tung oil appears to be pure tung oil.

Pure Tung Oil takes a loooong time to dry, but in my opinion has greater depth than BLO. In practice, you'd thin the Tung Oil with mineral spirits and add some japan drier to accelerate the cure time.

BLO has been through a "cooking" process where the curing process has already been kicked off. That makes it cure quicker than pure tung oil. Still probably good to thin it some to aid penetration and make it easier to apply.

The Watco is likely BLO with some thinner and additives that save you from concocting your own brew.
 

·
Registered
Joined
·
187 Posts
Discussion Starter #3
What would you recommend for a tung ratio with naphtha ? Can says 4:1 m.s. But I've read lots of different ways.
 

·
Registered
Joined
·
26,862 Posts
I don't know anything about the teak oil but tung oil is a far better finish than linseed oil. Tung oil is waterproof where linseed oil is barely water resistant. It's true it can take weeks for tung oil to dry if the weather isn't cooperating. The best way to tell if tung oil is dry enough for another coat is to briskly rub the surface with a clean cloth and smell the rag. If there is no tung oil smell it's dry. I wouldn't thin the tung oil any more than necessary and if you do use mineral spirits only. In my opinion any other chemicals or naphtha would harm the finish.
 

·
Registered
Joined
·
3,473 Posts
I wouldn't use naphtha either. Naphtha will evaporate faster, but it won't make the tung oil cure any faster. I think 50:50 to start. If that still seems hard to apply, thin some more.

Be sure to dispose of rags properly. The possibility for spontaneous combustion is a real thing.
 

·
Old School
Joined
·
24,017 Posts
Until you get a good build going they will look very similar. Watco Teak Oil has varnish resins in its mix, along with BLO and mineral spirits. BLO will impart more character to the grain than pure Tung oil, but will also add an amber color. Pure Tung oil stays pretty clear. Using Naptha doesn't change the oil as far as I have seen (compared to mineral spirits), and does seem to allow for a faster dry.




.

 

·
Registered
Joined
·
1,510 Posts
Cabinetman nailed it, the Teak oil isn't teak oil, but more of a danish oil (varnish/BLO/thinner), mostly though it's just thinner (over 50% according to the MSDS, ~35% of which is naptha).
 
  • Like
Reactions: cabinetman

·
Registered
Joined
·
213 Posts
Over time, the linseed oil will get darker than the tung oil. According to the MSDS, the Watco is linseed oil, though I thought it had tung oil in it also, or at least used to. The Behlen Tung oil appears to be pure tung oil.

Pure Tung Oil takes a loooong time to dry, but in my opinion has greater depth than BLO. In practice, you'd thin the Tung Oil with mineral spirits and add some japan drier to accelerate the cure time.

BLO has been through a "cooking" process where the curing process has already been kicked off. That makes it cure quicker than pure tung oil. Still probably good to thin it some to aid penetration and make it easier to apply.

The Watco is likely BLO with some thinner and additives that save you from concocting your own brew.

Most "Boiled Linseed Oil" you can buy is not true pure boiled oil, they have added metal driers among other things to it to accelerate its drying time and make it act like true Boiled Linseed Oil which has to be carefully brought to heat in a vacuum.

I don't usually thin the oils at all but when I do it's only by about 20%.

I would highly discourage you from using Japan Drier with a pure oil finish. You aren't really going to accelerate the cure time, but you will accelerate the setting of the microscopic top layer of oil, which can cause the deeper oil to take MUCH longer to set up and be ready for another coat. People that report tacky oil finishes taking a month to dry or never drying, have often used Japan drier. The metal driers and solvents in other oil finishes are formulated and mixed by professional chemists who have tested everything about the process. You aren't going to get the same result by squirting a teaspoon of the stuff into your finish before wiping it on.

As others have pointed out the "Teak oil" isn't a pure oil at all, just a thinned down varnish with some oil in it.

Pure unpolymerized tung oil is the way to go in my opinion, though you are correct that at first it looks much the same as Linseed. It's protective qualities are better though. Also over time Linseed Oil continues to darken more than any of the others, it can give a blackish cast that I just dont want my pieces to have in the future (20+ years.)

To speed the drying time try to keep the shop warm, and low humidity.
 

·
Registered
Joined
·
1,160 Posts
It would be expected that the three would all impart the same coloring to the wood. Teak oil is primarily linseed oil and tung oil has almost the same color as linseed oil. So they all are going to color the wood very similarly. About the only real difference is that pure tung oil dries very slowly. And Teak oil contains small amount of resin (varnish) which makes it somewhat more durable and protective.
 
1 - 10 of 10 Posts
Top