I just got this tank and the draw is extremely tight, the flavor is non-existant no matter what voltage I set my PV at. I was considering plugging the existing airhole and drilling a small hole at the top of the tank by the coil. Someone else on a different thread suggested it. My problem is, how do you drill a hole into a plastic tank without cracking it? Does the old drill trick of putting a piece of tape on the surface to be drillled work to prevent cracks? What size drill bit would I use? Picture of tank:

