Tip: Does Oil Swell Wood?

Judging from the comments I have received on a few of my videos (and another from a few years ago on a forum I participated in), there is a fairly widespread misunderstanding of what oil does to wood fibers. To demonstrate that in fact wood does not swell when saturated with oil, I set up a semi-scientific test using blocks of MDF. I soaked one in water, one in mineral oil and one in mineral spirits (paint thinner) and left them overnight. The fourth block was the “control” and I just left that dry.
The results:

The first one from the left is the one that was sitting in water and it has swelled noticeably. The next two were the oil and paint thinner and have remained unchanged after a full night.

Not unexpected was that I had some comments in the video below saying that MDF is not wood (!). I used MDF because it is made from wood fibers and will rapidly show the swelling, if there was any.

Here’s the video showing the test and the outcome: