I sanded all mine with 400 and 800 grade wet and dry, and the dust got EVERYWHERE, but i got a nice finish As for sealing it, i used thin super glue and Q-Tips, just put drops onto the Q-tip until it looked saturated, 2-3 drops was ok for me, and then ran it around the edge of the chassis, could do most of a side until it had dried too much, so just chuck that Q-tip and use another.