new here and i have learned alot. I've got one ? for you guys. Built a fluid bed and have tried several ways of putting in membrane. glue to bottom of cup, just sliding over and trimming I've tried brown bags and vacum bags and coffe filters. Brown bags seem to wrk the best but I still get little volcanoes with all paint. using a 30 to 60 gal pump with a air valve. even put holifill in the coupling trying to spread out air. my question is does every one get this little volcanoes and dust coming out the top of the cup when it is in use? thanks for any help.