: What constitutes "fairly close growth rings? I have what I bought below,
: don't know if it will attach successfully or not

Can't see the pix but if you look at several pieces of lumber you'll see that some have fairly wide spaced rings and others that have the rings closer together (more rings). There is a difference to the wood that's either at the hard spot where the ring is and the softer wood to either side of the ring. The trees with more rings minimize these differences and make the carving more consistant.

After you've done a couple paddles these differences matter less, I just point it out to make the first effort easier to get something you'll be happy with.

Bill H.