As I understand "water popping," when described to me, you can run a damp cloth or sponge over the top. If you live in an area with minerals in the water, you might spring 59 cents for a gallon of distilled water. Cheap insurance.

Be aware that if you are using #225 Red mahogany, this is an oil-based stain. You should let it cure at least a week before attempting to top coat with a water borne finish.

If you don't want your spindles to turn, they should have been glued in. I am not fond of nailing them. It creates problems down the road in removal and it creates a stress point, often leading to cracks. If you can't get the spindles out, I'd probably drill 1/16" holes around the mortise area and shoot in some Elmer's or Titebond white glue with a 21 ga. syringe. Wipe off the excess with a damp rag. I'd wait until finishing is done so you don't end up with glue splotches when you stain. Either that or "left-loose; right-tight" -- no wait, thats for screws. ;-)

interesting- thanks for the tips. They ended up coming over and water popping. My floor was done with #225 Red Mahogany and they put 2 coats of waterborne finish on 48 hours later. One was StreetShoe and the other was Bona - soemthing - a sealer. Oh well, it looks great at this point. We shall see! Thanks for the help with the balusters...

I forgot to mention -- if you end up drilling holes, they are less conspicuous if you choose to drill in the open pore sections (early wood). If the hole bothers you, get a matching color (or two) wax fill stick / pencil / crayon and smear it into the hole and buff out with a piece of grocery bag paper.

Here is a link that might be useful: Blend-fill pencils