The chamber cleaning crew (Mark Layne, Chris, with Carolyn as recorder) was in BSC-7 this morning, and using the indomitable "5 of 6" air drill, cleaned eight more sections. They also touched up around several fins. 46.59% of BSC-7 has now been cleaned. Mick worked on the other five drills throughout the morning and made a couple of modifications. Tyler Guidry worked on fabricating the first of our chuck replacements. Mark and I went back into chamber after lunch to fit check the prototype bellows vacuum attachment (too thick, suction vents on ID rather than on OD, handle overly long for application). We also examined the quality of the finish left by the large rounded brush vs various cup brushes and tried to determine a path forward for the lower part of the chamber (when to remove the flooring, do we need some flooring in place to remove dome cover, safety implications of partial flooring, etc). I took a few pix for documentation, then we replaced the dome cover and door cover. Mick performed the end of day checks and blow-outs. Mick and Mark moved the compressor trailer back into the LEA and Mark ran a few test with a drill that Mick had modified earlier in the day.