coolant or oil (they do similar things) is your friend. YOu don't want it too slow with the very small bits. Good firm pressure so that you make nice chips. Sharp bits. IF you don't get the drill to dig in it will just sit there and rub and dull and work harden the work piece. Drill bits most often break because the flutes get too full rather than because of firm pressure (within reason of course). Any old oil will do. Even bacon fat (is there anything that bacon doesn't improve????).
RV 4, O-320, wood prop, MGL iEfis Lite
VAF dues 2019