I'm gonna piggyback onto this discussion because I'm planning to
skim-coat my bathroom walls to match the rest of the house.

I've torn out all the walls and the floor, replaced the tub, and now I'm
ready to put the walls and the subfloor back. The rest of the house has
plaster over gypsum-board lath for the walls.

I'm planning to use 1/2" concrete backer-board (Wonderboard?) for the
walls and then skimcoat the sections that I don't tile. Does this sound
reasonable? The bathroom is so tiny, I don't think the small sheet size
will be a big problem (just a nuisance because I'll have to do a lot of
cutting to get the joints to land on the studs.) I will tape the joints
with fiberglass mesh.

Do I skim it with a 45-minute setting-type joint compound, or is there a
special plaster I buy for skimming? I know plaster of paris sets too
fast to be workable.

Thanks,
Bob