Fuel tank drain?

[Trevor778]

Hey all, Im just finishing up my fuel tanks and trying to get the drain to install properly. After only 2-3 threads catching it becomes extremely difficult to tighten. Are people tapping the drains prior to install? I'm definitely not stripping the threads, just seems like an excessive amount of pressure is needed to tighten. Thanks for the replys.

Trevor

[alpinelakespilot2000]

It gets pretty tight pretty quickly, Trevor. You definitely won't be using all the threads on the drain and you definitely don't need to tap it first. Using some fuel lube (EZ-Turn) will help a bit, both with the tightening and making sure the threads seal well. Hope this helps.

[terrye]

You know these are pipe threads right? Pipe threads are made with a taper so that the more you tighten them, the closer the thread crests and roots get. The taper is 1 in 16 measured on the diameter and along the longitudinal axis. Coat the male thread with fuelube and if you can tighten the drain fitting 2-3 turns hand tight, then another 1/2 to 1 turn should do it.