On Saturday, October 1, 2016 at 12:30:25 AM UTC-4, Gunner Asch wrote:




"Post arc delay" has nothing to do with the weld. Lift your foot off
the pedal and the arch shuts off..yet the gas continues to run for X
seconds.

Do machines with water cooled torches not have that delay?
tilts head

Water cooled machines can set that time from 0-60 seconds (most of
them) and its used to cool off the electrode/torch after the weld.
With most water cooled torches and power ranges of the average hobby
shop...its mostly not needed. Pure Tungsten electrodes might benefit
from it..but any others...nah...Id not worry about them.

Gunner

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I agree the post arc flow helps to cool the torch, but that is not the reason for it. If the gas stopped flowing the instant the arc stopped, the torch would not get hotter. There is no energy being used when the arc is off.. The post flow is to keep the weld and the tungsten in inert gas while the weld and tungsten cool enough that they do not oxidise. If you want to see the effect on the weld, just whip the torch away from the weld the instant the arc extinguishes.

Dan