[log in to unmask] writes:

<< WARNING: Wet sanding will increase humidity in the space & will possibly
 result in getting books & papers wet. My suggestion is don't sand, just coat
 the floor & walk on it. Turkish carpets make good covers for bare spots and
 you can layer them. >>

OK, I give up, here's what I'm going to do:
    wet only the areas surrouding the patches to be sanded
    get a big 3 mil tarp, lay it over the problem areas
    put a power sander (with vac bag) under middle of tarp, weighted at edges
    sand floor, hope tarp and wetted perimeter traps dust
    remove tarp, remove dust, lay poly
    report back to BP, accept praise or damnation

Sign me,  Ashes To Ashes