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I recently finished an oak butcherblock desk with mineral oil. While the surface looks great, I just learned about the difference between non-drying oils and drying oils, and I'm worried the desk will forever leave oil stains on my papers.

Could I refinish it by simply applying a drying oil (tung or linseed) over the mineral oil? Or would I need to completely sand off the layer of wood that soaked up the mineral oil before refinishing it? Any other ways I could salvage the situation?

Note: This is an office desk and does not need to be food safe, I chose the butcherblock & mineral oil combination based on looks alone.

  • Update after refinishing: I used @Graphus's suggestion to wash the oil off with mineral spirits. This significantly reduced the oil, but the surface was still slightly greasy, so I ended up resanding the degreased surface (which was much easier after removing the bulk of the oil). I refinished using a wipe-on varnish (4 coats), and was very pleased with the end result. – Tim Allclair Aug 7 '17 at 20:58
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Could I refinish it by simply applying a drying oil (tung or linseed) over the mineral oil?

The standard answer to this on woodworking forums would be no, but in reality it might work acceptably. However, it's likely to compromise the ability of the drying oil to 'dry' properly, and this effect will be permanent, so it's safer to work to remove as much of the mineral oil as possible before applying any other finish.

Since mineral oil, like all oils, is easily soluble in mineral spirits (UK: white spirit) it can be used to rinse a lot of the oil from the surface wood fibres.

You'll want to use generous quantities of spirits and plenty of fresh cotton rags or paper towels to soak up liquid, perhaps doing three rinses and wipe-downs and then leaving the table to dry.

The next day check that the surface looks fairly uniformly de-greased and locally treat any areas that still look wetted with oil.

Safety note: normally the fumes from spirits are not a big deal but we're not usually using them in quite this quantity so if possible do this job outside. If that's not feasible work in the most well-ventilated place possible; a garage with the door wide open would be good if available. Even after the rags/paper are bagged up and thrown away the table itself will give off a lot of vapour as it's drying out so you wouldn't want to leave it in any room you're using for another purposes.

Once the cleaning is complete you can apply the drying oil of your choice. It won't hurt to thin an amount of the oil with spirits for the first couple of coats; a 1:1 dilution works well. My recommendation for the oil would be BLO over tung oil as it makes the wood look better faster, is easier to get and costs less.

Incidentally you can also use varnish, or an oil/varnish blend, to provide better durability and water-resistance.


Incidental point on wood removal:

Or would I need to completely sand off the layer of wood that soaked up the mineral oil before refinishing it?

For the average home woodworker sanding should really be the method of last resort to remove a layer of wood from a large flat area, it's generally only a good method where there is access to a wide-belt sander. When working at home if you're thinking of taking off a layer of wood your first thoughts should be plane or scraper, both of which are faster and more efficient than sanding and produce much less fine airborne dust.

  • Thank you! To clarify: are you suggesting that a thorough washing in mineral spirits should be sufficient to remove the mineral oil prior to refinishing (as opposed to planing / scraping / etc.)? Also, does it matter how long I wait before doing the spirits wash (I applied the mineral oil 4 days ago)? – Tim Allclair Sep 9 '15 at 17:52
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    @TimSt.Clair, yes a thorough washing/rinsing in mineral spirits should be sufficient to remove enough of the mineral oil from the surface wood fibres, so that no wood removal is necessary. "Also, does it matter how long I wait before doing the spirits wash (I applied the mineral oil 4 days ago)?" Nope, because it doesn't dry it's much the same day 1 as it is day 21. – Graphus Sep 9 '15 at 18:15
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This might be overkill, but good if you want to leave no trace of oil.

I find the most effective solution is a good soaking and washing with acetone. And after the acetone dries, repeat the same steps with brake cleaner.

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