Australopithecus scobis wrote:

Idea just occurred to me, never tried it: wrap a finger around the air
holes at the back of the nozzle when you fill the jar with propane. No
sense mixing in additional atmosphere, right? Also, the valve should be
open just above a trickle so you don't entrain too much atmosphere. If
we're very lucky, we might see enough Schlieren effect to tell when the
jar's full of propane.


Beats the hell out of me.

I just put some propane on top, close the lid, and go back to boat building.

Works for me, SO FAR.

Lew