why? I realize the gasket is supposed to butt up against the hood's "stop"....but....my filter goes in from the front. So i was wondering if i should put it in with the gasket facing backwards so it seals up good.
No matter though....i bought some new gasket foam and put it on the back side of the filter. I have 2 coats of paint for the inside....and Cherry stain and poly for the outside. Pics when it's done either today or tomorrow.
Your HEPA filter is constructed in a graduated manner. The entry face of the filter has larger pores than the output filter face (on a microscopic level). Coarse particles are filtered out upon entry and the finer and finer particles are gradually filtered out as the air passes through the filter.
Ever tried to use a funnel backwards?? Essentially that's what you are doing by flipping your filter around. It'll work for a little while but it will quickly become plugged by coarse particles.
But don't take my word for it (because it appears as though you haven't). Consult the manufacturer and see what they say. I've spent enough time in cleanrooms to know that the manufacturer always has a reason when they suggest a manner of installation. For the money you spent on that filter, they should gladly give you a few minutes of explanation.