One thing to remember with flash times, air movement assists with the outgassing of solvents. So if you plan spraying any catalyzed paint products, ie: Urethanes or clear coat, keep in mind that a home brewed fan system may not have the air movement of a designed system in a booth. Add some time to your flash times accordingly to prevent any issue with solvent pop... Your "test spray" with epoxy should let you know how well the fans work by observing how fast any overspray moves on out...
