g4qber wrote: Correct dry air is good. Where do we get it?
To some extent, compressor air, if sent via a storage tank, is likely to be dried a bit anyway. Water vapour in the compressed air cooling in a tank will condense so the tank should have a drain. When the air is drawn off the tank it will be drier than the source air was, albeit not super dry.
In a previous life I used to open the manual drain on a compressed air tank once a week before we got an automatic drain. In our case we wanted extra clean, laboratory grade air so it went through further drying and various stages of filtration for hydrocarbons and other things. That air was then drawn off for various scientific instruments or to feed a nitrogen generator that stripped out the oxygen to feed very clean nitrogen to various instruments. For ordinary car tyres, I'd say the dryish air from an ordinary compressor/tank arrangement should be fine. Not quite good enough for a sensitive mass spectrometer, but that is not what we are doing here!