Untapping flange
Last updated by: SDM 8/25/2015
Do your homework
Talk to other members of LASE for advice. Also consult Terry and James -- they have experience removing the tapping from flanges.
Equipment and safety
Lots of IPA - acts as a coolant and flushes away stainless steel chips during drilling. It is also easier to clean up than oil
An appropriately sized blank for the flange to be drilled - Needs through holes and will act as a guide for the drill
Gasket for the blank/flange interface
Cobalt steel drill bits - Tough bits required to remove the stainless steel. Make sure the bits are long enough to drill through all material (e.g. flange to be drilled and blank above flange). Previously purchased from McMaster. The bits need to be the same size as the existing
Cordless drill and an extra battery - Expect the batteries to become drained during the
Kimwipes - To catch the IPA
Foil - To catch falling debris that is drilled out
Procedure
Practice
Practice on another similarly-sized expendable flange to get a feel for how sensitive the flange is to the drill. This is also a good way to calibrate your speed and the amount of IPA to use (e.g. Do I need to mix IPA + H2O or is just IPA okay? If I need a mixture, what's the correct mixing ratio?). There are typically spare flange pieces in Terry's office -- just ask him.