I realize that this is a completely nutty idea but I thought I'd throw it out there anyway.

I have a 2kW air cooled Teknomotor spindle and it's much louder than I expected. It turns out that all the noise is from the impeller mounted at the top of the spindle. This is borne out by the fact that covering the inlet with your hand eliminates about 90% of the noise from the machine.

The air cooling is accomplished through 4 through ports running from the top of the spindle and exhausting out the bottom. I think that by making plastic plugs for the 4 ports with an inlet/outlet for a tube, I could probably convert the spindle to water cooling and, it would be reversible. As a side benefit, I'm sure the thing would run a lot cooler too.

The most difficult part would be removing the impeller I imagine.

Am I totally off my rocker or is this something that sounds kind of feasible?