Blowing air (even through filters) will likely push containments on to the work and the fumes won't be removed from my garage.
my experience is with automotive paint booths with doors
the nicer booths have 2 fans; one fan pushes air thru the intake filters into the booth and one fan sucks air out of the booth thru another set of filters
pushing air thru a filter into the booth works for $10,000 paint jobs. granted we use filters a little better than a furnace filter
with only exhaust fans in an open booth the only air you will exhaust will be coming in the front opening, with all of it's contaminants
the only dust or dirt you will see on the top filter will be dust that settles on it, there will be no air flow thru that filter
as for explosion proof? the only way for an electric motor to be explosion proof is to either buy explosion proof motors, very expensive
or remove the motor from the air/vapor stream, which is how a paint booth would do it