: . . .I'm not sure if it's true but
: supposedly if you finish sanding with 320 or whatever they use
: for plumbing it will stengthen the paddle. Don't remember the
: theory (something about closing up the spores?) entirely but it
: seemed to make sense.

I sat through a woodworking show presentation by a furniture maker who sands with progressively finer grades until he is up to a 4000 grit sanding pad. With no finish at all the wood is beautifully burnished. He too said something about the extra -fine sanding closing the pores in the wood. He passed around the sanding materials, and that final sanding pad didn't seem to have any grit to it at all--but the whole process give a beautiful result. Once you get past 400 grit there is not a lot of roughness to remove, so the progressively finer grades do not take a lot of time.
You can get 2000 grit sandpaper at an autobody shop, and even at Wal-mart.

PGJ