Quote Originally Posted by McCreed View Post
. I would add that regardless of the shielding method, it wouldn't hurt to seal the cavities with a few coats of shellac or poly before wet sanding. It just prevents any absorption of water and potential swelling of the wood. There shouldn't copious amounts of water getting in the cavities, but better safe than sorry IMO.
And a good point from McCreed.

I'm so used to spraying, where the cavities get coated in the finish, that I mentally exclude other methods of finish application, where it depends on whether you've run the finish into the cavities or not.