I am re-using existing luan underlayment floor, in preparation for
installing new vinyl sheet floor. This is on the advice of my
installer, who has seen my floor underlayment and recommends its re-
use.

Which type of sander should I buy, to touch-up the skimcoat after I
have spread it?

Random orbital, belt, vibrating pad?

Please reply urgently. I am buying the sander tonight. I appreciate
any input you have.

PS - I cannot stop the group from pontificating at length on my
situation. But please: if you must type 1000 words on the wisdom of my
project, at least throw in some advice about the sander.