I have a set of stairs I've built for a loft and hadn't given enough thought to the final finish. The stringers are solid with 1/4" pockets that accept 2" thick treads.
I am looking for a crystal clear finish - and have sort of settled on this stuff:
Varathane Interior Water-Base Matte Crystal Clear Wood Floor Finish Polyurethane
However, I'm unsure if that's the right product, or if there is something better? The one concern I have is slipping - I've seen Osmo Polyx Anti-Slip as a recommended finish due to the anti-slip properties, but I would like to avoid yellowing (I realize the wood will yellow/darken over time, but would prefer that the finish doesn't contribute to this). I could also put down grip tape, but that's a measure of last resort.
The other question I have... do I prefinish or finish once they are installed? I've already routed the pockets and if I pre-finish the treads, if the coating is too thick it will prevent the boards from going into their pockets. I know pre-finishing will make the final finishing step easier - do I carefully sand the edges where my tread fits in, or is this a case where finishing after will be easier (in a twisted sort of way)?
Thanks!
John