On Jun 12, 7:51 pm, wrote:
So, I want to redo the floor in a cheap little cabin. The subfloor is
particle board, covered with linoleum tile, subsequently carpeted.
I've removed the carpet and tile (shingle rake was helpful for that).
The particle board has gotten wet in some places and softened and
gotten lumpy, and doesn't smell very good. I'm thinking of trying to
seal it with some sort of paint or varnish or something, before
putting a plank floor on. Something that would soak in and harden and
restore some integrity to the soft spots, and seal in the musty
smell. Anyone have an idea as to what might work, or general advice
on dealing with particle board subfloors?

I agree with Edwin. Rip it out and replace it. Better to do it now
before you invest a lot of money putting new flooring over it only to
have to rip it out later.