Can a block of ashwood float in Methanol?

No, not any substance, but some, and here's why. Methanol has a density of 0.79g. If you put something in the methanol, say wood (oak), that weighs 0.89g, which is more, it will sink. It all depends on if it weighs more or less than the methanol. If it weighs more, it will sink, If it weighs less, it will float.