Alexis, yes try the baffle idea - maybe it will help you, though it sounds like your fan is doing a much better job pulling the air than mine is. I'm afraid this washtub idea is not ideal - If I'd wanted a box type of vent system, this is not how I would have designed it... and I'm afraid I'll only be able to look at it for so long before I need to do something differently, but who knows, maybe I'll grow to love it (hope, because I'm ready to move on to the melting glass/creating art part). I hope the extra sheet of metal will work for you. The sheet of metal I got today was only $11 at home depot and is flexible so it curved with the tub. I just had to cut part of it a little shorter and then taped it in. If that helps.
Leah, yes it's going to be a good friday all around
Thanks for the well wishes, I'm going to have fun out there no matter what, even if it's just organizing glass and setting up my bead table!