<p>It worked! This is the "final" configuration for my new forge. I started with Geoff Keyes' posting on care and feeding of blown burners and kept puttering until I got the temp range I want (1250F-2350F) with a nice smooth burn! I'm sure the squirrel cage fan is not really pumping 180CFM against the back-pressure even at full speed - but it's just right to top out where I want (2350F). I'd tried a 1-1/2" pipe first but it could get too hot for my insulation (rated to 2400F) and couldn't hold low enough for heat treatment w/out back-burn or flame-out. 1" pipe works jus