Shellac is way to fragile for that environment. It is disolved by
alcohol, so spilling some cologne or other items in the bathroom will
be a solvent.

Yes, Poly is the best bet. It can be hard to get a good finish with
poly if you aren't familiar with applying it.

1. It can change the color of the wood slightly.
2. It can easily attract dust while drying because it typically takes
a long time to get a dry film.
3. Application problems from drips to orange peeling to a too thick
application that looks like plastic.

Not to scare you off, just impressing that you should familiarize
yourself completly with the materiasl and process on some scraps
before commiting to the real piece.

Many folks fine wipe on poly a great solution for application when you
don't have a spray setup, etc. Much easier to get a good result than
brushing only. Again, if you go this route, try out the process until
you get good at ot and a result you like.

I prefer 3 or 4 very thin coats. I thin standard poly 50% or more with
mineral spirits to make my own. Apply with a brush then wipe down with
a rag dampened with the same solution until almost none on surface at
all. If thin enough, you can barely tell it is on there but still get
a film protection. You can also build to a greater finish. Always
lighty sand between coats after 12 hours or more of dry time. Use 400
or even 0000 steel wool or maroon synthetic scrub pad. .

On Aug 29, 8:06 pm, "Rodney Taylor"
wrote:
Installing a vanity in master bath that I built myself, i am wondering what
is the best way to protect it from moisture. Considering shellac or
polyurethane any comments or suggestions?