metal valve stems. How tight?

[w.michael]

When installing inner tubes with metal valve stems:

1. On the tube, how tight do you tighten the lock nut against the bridge washer? Just until the "squish" is gone? If it's not tight enough, I guess it will leak. If it's too tight, perhaps you could actually mash the tube out of the clamping surfaces.

2. Once the tube is installed in the tire and on the wheel, how tight do you tighten the rim washer against the rim? Does the lock nut bottom out against the inside of the rim, or does the bridge washer create an "air gap" between the lock nut and the inside of the rim?

It's hard to even ask the question until you've tried it!

Thank you.

W. Michael