Have noticed some guys use bondo for filling holes in wood. Tried it, and the results are good. Problem I have is the bondo I have found is white. So I have to color it before finishing. When I was young in the 60's, I bought a product called "black magic", which was a body filler colored black. Anyone aware of a black bondo product? Usually I am filling a knot hole in walnut, and lots of knots in walnut are black, so it would be a good color for me.