Durability Issues with an Oil-Based Finish

Finisher wonders why re-coats of Tung-based formula are showing unexpected softness. June 17, 2010

Question
I built some Jatoba kitchen counters 3 years ago, and used Waterlox as the finish. I put on about 5 or 6 coats when I built them. I have scuffed and reapplied one coat per year, and it seems now like the finish is just not holding up as well as originally. It develops light surface scratches easily, and they don't look good over this beautifully dark wood.

Can I go over the Waterlox with another type of finish that would be more scratch resistant? The Waterlox I applied the last two times did not seem to dry as hard as the stuff I used 3 years ago. Does anyone know if they changed their formula? I was hoping to scuff the Waterlox and apply another solvent based finish.

Forum Responses
(Finishing Forum)
From contributor C:
Were you using their original tung oils or marine finishes?



From the original questioner:
I used the original Waterlox sealer/finish.


From contributor C:
All I can recommend is to do an aggressive sand job to remove the bulk of your old coating, or all of it, and use another product like Southerland Wells polymerized tung oil for new application. As far as I know, they have not changed their original formula, so that shouldn't be the problem.

Did you check the date before use? Did you, after applying the sealer, evacuate the air and replace with inert gas like bloxygen? Oxygen in the can will react with the already present cobalt drier/tung mix in the can and cause further polymerization (thickening) which would tend to appear or work harder than a fresh unopened can. Outside of this I can think of no more off the top of my head that might be happening, but again - I think you would be better off just sanding off and using a different product. I've never been fond of Waterlox.



From contributor P:
Have you thought about contamination from whatever was used to clean the top over the years?


From contributor C:
Yes, I thought of asking that, but he scuffed and sanded, so I left it out. Wax or polishes, if they were used, would cause adhesion problems.


From contributor R:
My suggestion would be to use a cabinet scraper to remove as much of the coating as you can. Trying to remove an oil coating by sanding can actually burnish the coating into the wood, just the opposite of what you're trying to accomplish.

Once you have removed the majority of the oil, sanding is in order. Waterlox has been a fine product and the projects I have used it on have held up quite well. Knowledge and experience have prevented me from using it in a kitchen environment, but the projects I've applied it to look swell.

Keep in mind that it's a good idea to remove all the existing finish before attempting a re-coat. No use applying a new coating over an old coating if the older coating is failing. Although I'm a fan of tung oils and I know they have been used for centuries, I would consider a beefier coating for the countertops.

Something like a 2k poly or even a conversion varnish will offer much more scratch resistance than an oil finish will.

To completely remove a contaminate that was introduced by using cleaners or waxes, a scuff sanding won't do the job. Scuff sanding with 100 grit paper is not as efficient as doing a thorough sanding with 120 grit or even 150 grit paper.

Considering your countertops are 3 years old and you have scuffed and applied a new coat each year, my guess is an oil finish isn't the best coating for your application.



From the original questioner:
Thanks everyone. We have only used mild cleaners on the tops. The heaviest use area, the island, is where the biggest concern is. In fact, the sink area is in about the best condition of it all. I did use newer material, within the expiration date.

One thing I forgot to mention, and maybe this is the bigger problem, is: In an attempt to try and kill some of the redness in the color of the wood, I recoated a year and a half ago and tinted the Waterlox with some green tint. I was advised by my finish supplier it would be okay to use Mixol green in the Waterlox to tone it a little. I used a small amount of tint to see how it would go and the Waterlox never seemed to dry fully. I gave it a couple of weeks, and when it still felt tacky, I realized I had to remove it.

I sanded it back to what I thought would have been deep enough to get it all out, and recoated with a new can and no tint. It dried pretty quick and seemed okay, but didn't hold up as originally. I waited, and recoated again this past fall, and I am still not happy with it.

It sounds like I have to strip it and start over, which is okay. I just don't think I want to do the Waterlox again. Is there a brushable 2k poly, conversion varnish, or other suitable product that I can use? I wouldn't be able to spray it, so I definitely need something that can be hand applied. I am leaning away from the tung oil products at this point, based on this experience, and I really appreciate the guidance from the veteran finishers here.



From contributor C:
What I use on cutting boards is food grade mineral oil, and since you seem to be responsible with your maintenance, I would suggest that to you. Beeswax is also a good choice if applied thin and burnished off real well with burlap to a very thin coating.

I shy away from resin coatings not because they are inferior, but because I find that they dull my knives quicker on areas where I cut, especially the harder ones. Not much, but enough to annoy me. I find knife to wood contact to be more forgiving - especially if the wood is end-grain type. But then I cook a lot, so if that's not a concern for you, be my guest.

You can also melt the beeswax into the oil and make a hybrid finish that will give you much better water resistance than the oil alone.



From contributor L:
Be careful on the advice you choose to follow. Beeswax is flammable and will start on fire if it the wax comes in direct contact with a flame.


From contributor R:
Your post reminded me of something I once read and it went like this "removing safety warnings on finishing materials will put an end to stupidity." If you take a brick of beeswax and run it over a cheese grater, you can put the shavings in a crockpot and set it on medium. Crockpots are another handy item to have in the finishing department.


From contributor C:

Yes, do not melt and mix over a direct flame. The usual mix is 1 cup of oil to 1 oz of wax. By the time that is applied and spread out and buffed with rags, there is nary a chance of fire, unless you're purposely putting a blowtorch to it. Of course a major fire would cause this to happen also, but then no matter what you had on there, it would ignite and burn, even Formica.