Tuning pegs for musical instruments are commonly made from ebony or boxwood, but in medieval times and renaissance they would also be made from roasted maple. Maple is a relatively soft wood, so the trick is to roast it, which makes it very light and porous, and then let it soak in a mixture of linseed oil and turpentine overnight. It soaks the oil in like a sponge, going from swimming on the surface to sinking to the ground when it’s saturated. The oil hardens and reinforces the wood, kind of like epoxy stabilised wood.
Honestly, I don’t know. I didn’t expect to see literal air bubbles rising from the wood in the oil bath. That’s a lot of oil, so I expect several months for it to fully harden. Maybe I can speed up the process with an UV lamp.
Linseed oil polymerizes very quickly. It probably won’t be as long as you expect.