yes, this stuff will do the job. you only need a thin coat if you are going to spray before fitting the components you can put on the thicker coat after you have done your repairs.
make sure you mask off any connection areas on the board with masking tape, you don't want any lacquer on the pcb tracks / traces where the connectors slide on (A1-J1 A1J6 etc.) I know most or the contacts or on the bottom of the board but you can still get minimal amounts of over spray on there.

make sure the board is clean from any dust or oily residues or else your clear lacquer will not stick and look horrible. use PCB cleaner for this
and last make sure if you are going to spray any I.C. sockets that do not have the I.C. installed that they are masked up also.