Re: White Pine Wood I believe you are talking about the cambrium layer, but that is rather thin for carving (far less than an inch. As long as you stay away from the heartwood you should be ok, and i some instances, even the heartwood is fine for carving.
As you live in the Mpls/St.Paul area, check with some of the local log home builders; they usually have good supply of cut-off ends, some up to 4 feet long nad a foot or more in diameter, which are just thrown away or burned. should be able to pick some of these up reasonably.
Al |