07-13-2016, 07:08 PM
(06-24-2016, 04:07 PM)TomG Wrote: Those must use a LOT of argon! I'm sure they are run at very low volume, but it's a lot of area.
BTW, sorry about the six jaw expenditure. :)
Tom
Hi Tom,
I always asked the same question about purging the back side of welding jobs, but of course when training as a Metalllurgist and later a weld inspector my point of view changed to "What is the cost of a failed weld?" I have always protected the back side since (covered my What?).
A weld failure is often so far more expensive than a little sheilding gas and of course these boxes will actually hold the gas in place unlike the torch side of the weld which is so very turbulent that it blows the gas away. As corrosion of the metal occurs more strongly at high welding temperatures and the back side of the piece suffers through exposure at a lower temperature the back side needs less chemical protection, ergo only a small amount of gas is required,
My setup includes a small needle valve and I set the gasflow low and check to see if more is needed, It rarely ever is.
Truth is sometimes all I do is cover the back side with a cover strip and this inhibits enough airflow if clamped tightly but when quality is of prime importance gas purge every time
Best regards
Rick
Whatever it is, do it today, Tomorrow may not be an option and regret outlasts fatigue.