Raw linseed oil on counter top: drying time?

Question

I have a new pine countertop that I'd like to match some existing pine kitchen surfaces nearby. The previous owners of my house finished the existing counters with raw linseed oil, so I decided to follow this process for the new pine surface — even though it is not a food surface, I decided a matching look would be nice.

I mixed 2 parts raw linseed oil to 1 part mineral turpentine, a ratio I found somewhere online that appeared convincing. As the previous owners did on the existing counters, I added a touch of stain to darken the colour just a bit.

I applied 3 thin coats of this mixture with a paint brush, allowing ~10 hours between applications, waiting for the surface to be dry to the touch.

Now, some 10 days and quite a lot of fan-blowing time later, the new counter is still very ... oily. It's dry to the touch, but leaves an oily residue on my fingers. A brown residue can be rubbed off on paper, and any paper left sitting on the counter blots up tell-tale oil.

The air has been relatively dry, and temperatures have been around 10 to 20ºC (50 to 70ºF). Edit: humidity in the 50 to 80% range, top stored indoors.

How should I proceed to get the surface to 'set'? Is it just a matter of more time and more air, or should I be wiping the surface down with something to get rid of the remaining oil?

Thanks!

Answer 1

Raw linseed oil does not harden. That is the fundamental difference between raw and boiled (often chemically treated rather than actually boiled, these days) linseed oil. It will be gummy for a very, very long time.

You would probably want to remove as much of the surface oil as possible and re-oil with a hardening oil - boiled linseed, walnut, etc.

Answer 2

In addition to Ecnerwal's great suggestion, you can first try to simply wipe/scrub down the tops with turpentine, trying to thin the oil a little to let it dry better. Sounds like you may have put it on a little heavy. In the future, let each coat dry a week or so before the next coat.

Once wiped down, you may be able to work some old school paste wax into the top. This is alot of elbow grease, but will mix with the oil further, and give a substance to dry it out with. It's gonna take alot of buffing, but will provide a good top finish. Apply as many coats as you like.

I suggest the wax because linseed oil alone is not very sanitary. Mixes well with food products, and you may find, over time, mold and mildew will try to form behind/under counter top appliances and decorations. Paste wax should reduce this.