Tung oil on MDF?

Brian Altop

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Tacoma, WA
I was going to put tongue oil on my MFT table (holy Festool table, no doesn't belong in church!:D). It has a MDF top with 20mm holes drilled all over the place for those who are not familiar with what it is.

Any way, I am either going to wax the top or I thought of Tongue oil. Would the tongue oil cause the binders in the MDF any troubles or cause it to swell?

Thanks!

I just want to keep the top safe when I do occasional quick glue or put my coffee cup down on it.

Brian
 
Brian, are you thinking of real tung oil, or one of the tung oil finishes? (Essentially a wipe-on varnish that may or may not have real tung oil in it.) Either one should work, but if you're using the real thing, keep in mind that it can take it a while (weeks) to cure. Also, neither the real stuff nor the "tung oil finish" varnishes are real durable. For something more durable, I'd suggest something like wipe-on poly, or even poly floor finish. Either the oil or water-based versions would hold up well to wear. I used water-based poly (Minwax Polycrylic) on a lot of my shop jigs and sleds and it has held up real nicely.

Cynthia, here's an MFT (multifunction table):

http://www.festoolusa.com/products/mft-multifunction-tables/mft3-multifunction-table-495462.html
 
Vaughn I beg to differ with you on the durable of Tong oil finishes. Once they are cured there as tough as nails. My oil flint lock has seen many days in the woods , on the live in rain, snow and bounced around in the van in tents. And still has a tough hard finish. The Watco tong on oil finish when prepared and executed properly is as hard is not harder then most of Today's varnishes.
 
About four years ago, I made a 'breakfront' cabinet for my sister, and since she was planning an upcoming remodel (likely granite counter tops), I made her a "temporary" top for it out of MDF, edged in oak.

I finished the top with two coats of garnet shellac (for sealing, and for the color) and two coats of General Finishes Arm-R-Seal. It actually came out looking a whole lot like leather.

Anyway, so far she hasn't got the remodel even started, so the top is now four years old, and looks as good as the day I made it. I'd intended it to last maybe six months at most, but it's proven almost unbelievably durable.

So yeah - tung oil finish over MDF will work very well.
 
Vaughn I beg to differ with you on the durable of Tong oil finishes. Once they are cured there as tough as nails. My oil flint lock has seen many days in the woods , on the live in rain, snow and bounced around in the van in tents. And still has a tough hard finish. The Watco tong on oil finish when prepared and executed properly is as hard is not harder then most of Today's varnishes.

Dave said it before me. Pure Tung oil is very durable stuff and highly moisture resistant. My Brown Bess musket, made in 1976, has been through all the elements, neglect and abuse you can imagine and the tung oil finish is still unscathed.
However, I believe it might soak into the MDF like a sponge. It might require many applications to seal completely. BTW, reapplication is something you can do with tung oil.
I can't speak for the 'finishes' made with tung.
 
I would use Shellac to seal the table , brush out thin each coat and then apply the tong oil. But start 50/50 for 3 coats and then 2 coats 75/25 and then 100%
Watco is a decent furniture grade oil.

Sand between coats with 320.
 
Vaughn I beg to differ with you on the durable of Tong oil finishes. Once they are cured there as tough as nails. My oil flint lock has seen many days in the woods , on the live in rain, snow and bounced around in the van in tents. And still has a tough hard finish. The Watco tong on oil finish when prepared and executed properly is as hard is not harder then most of Today's varnishes.

I agree that tung oil is a tough and durable finish, waterproof too, but it's relatively soft compared to most polyurethanes. Or at least that's what I've seen Bob Flexner say in his books.
 
We use mdf for beds on our molders and tried oil and it gums up and gets sticky. You are better off putting on a coat of wax and letting it soak in, then apply two more coats and it will stay nice and smooth. Plus nothing you spill on it will stick to it.
 
I agree that tung oil is a tough and durable finish, waterproof too, but it's relatively soft compared to most polyurethanes. Or at least that's what I've seen Bob Flexner say in his books.

Book knowledge is never as good as hands on Vaughn. My tong oil finishes are much harder then urethane finishes. Your old BLO and Toug oil finishes have stood the test of time. I would rather strip a urethane finish then I would an old BLO or Tong oil finish. The main difference is; Oil finishes get harder and harder with time where urethane finishes get to a harden point and that's it. So I would say it's the other way around from my experience.
 
We use mdf for beds on our molders and tried oil and it gums up and gets sticky. You are better off putting on a coat of wax and letting it soak in, then apply two more coats and it will stay nice and smooth. Plus nothing you spill on it will stick to it.

Al oil with gum up if it is not boiled oils finishes. Also oil finishes should be applied in thin brushed out coats. Starting with a mixture of 50/50 then 75/25 then 100 but brush out thin to get a long lasting finish. Problem with most finishers they want a quick , fast solution to finishing and a high end look. Just can not be done with fast easy finishes. I have a table that is just about finished. Jarrod is applying the finial coat today as we speak and tomorrow we will buff it out and I will get pic's up of the final.
 
None of the above.

If it is a working surface, and I assume it is there is nothing to be gained by a normal finish. I make all of my patterns for arcitectural reproductions out of MDF, and they have to be able to stand up to repeated passes with a router. Normal finishes help not one little bit in the toughness department.

I soak my patterns with West System, especially the edges, applying until it will not soak in any more, then cleaning off what remains with alcohol on a rag, leave overnight, light sand and buff.

With this method the epoxy sinks in about an eigth on the flat, and about a quarter on the end grain, if you can call it that, and it makes it tough with a capitol T. Then you have a basically plastic surface that can take a lot of abuse, can be waxed so glue does not stick, and will take water in stride.
 
...
Watco is a decent furniture grade oil...

Watco is Tung oil and what? Some sort of varnish?

When you mention the 50:50 and 75:25 mixes, what are you thinning it with?

I agree that Watco is a decent oil finish, and I've used it quite often - just never thinned it.

A while back, I posted pix of a walnut toy chest that was finished with Watco Natural. It came out great, btw.
 
Thanks for the replys,

I use 100% tung (got the spelling right this time:D) oil. I've used it once on an old rocking chair restore that I did. Turned out nice. I followed the direction and thinned it out 50/50 with mineral spirits so it would soak in to the wood better, than built up 3 more un-thinned coats.

I usually put down some 1/4" ply on top my MFT and use it for glue ups using the straight edge guide to help with keeping everything square when needed.

Caught myself leaving a coffee ring on the top the other day and thought about doing something to help me out. I'm pretty good about keeping my coffee cup, soda, malted spirits, off of the cast iron surfaces, but for some reason my mind can't seem to grasp not putting down beverages on a piece of flatwoork or my MFT table:huh::huh:.

I've got a quart of TO left so I think I will use it and give it a shot. I'll probably do that this weekend. I'll post pics etc when it is done. It probably will take a bit to cure till I can use it, I'll find out and let you know!

Thanks for the input, I'll be glad to hear any continued advice!


Brian
 
Book knowledge is never as good as hands on Vaughn. My tong oil finishes are much harder then urethane finishes. Your old BLO and Toug oil finishes have stood the test of time. I would rather strip a urethane finish then I would an old BLO or Tong oil finish. The main difference is; Oil finishes get harder and harder with time where urethane finishes get to a harden point and that's it. So I would say it's the other way around from my experience.

Dave, you're equating toughness to hardness. They are two different properties. Your oil finishes are hard to remove, but they are not physically as hard as poly. (I'm referring to the something like the Vickers hardness scale.) Yes, hands-on typically beats book knowledge, but your observations refer to the toughness of the finish, not the hardness. ;)

I suspect the reason the oil oil finishes are so much more difficult to remove is because the oil penetrates the wood deeper than a poly finish.
 
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