post flow to long?

[Glenn Bon]

On my econotig I think the gas post flow is approx. 10 seconds. During this time should the torch be left on the last portion of the weld for purge or is it just to cool the tungsten? Is this a normal amount of time, it seems there is a lot of weld time "gas" being wasted. From reading the manual it seems there is no adjustment, or is there? I guess I've got to much mig in my blood , off on the trigger - off on the gas. The begining of the learning curve.

Glenn

[Paul Seaman]

Glenn Bon:
The torch should be held above the welds finishing point until the flow finishes, or the weld is solidified which ever is first. This is a tough thing to remember when you jump from one to the other frequently, which I've been doing lately.

Peace,

[Bendaman]

Your right, the postflow is for both the tungsten and the cooling of the weld
pool. I'm not sure if the Econotig has a postflow adjust. One sign of weld
contamination is black tungsten or a black weld bead area.

[KB Fabrications]

Glen,
Welcome to the forum. My short and fast answer is that postflow time depends on what you are welding, not to mention gas cup diameter, tungsten size, etc., etc.

YES the torch should always be left on the last part of the weld. If your post flow isn't adjustable then at least you use that gas to ensure the weld has cooled properly (small price to pay to ensure quality). I will sometimes weld .035" 4130 tubing with 1/16" tungsten and only set my machine for 5 sec. postflow with fantastic results. Then, I'll weld some stainless of the same type and need to increase postflow to somewhere around 10 sec. Your regulator and selenoid may have some minor effects on postflow but nothing that can't be worked around.

Once you tig for a while it will become intuitive. Until then, I seem to remember some parameters printed somewhere that you can use as a guide (sorry I can't remember where, maybe someone else will know.) You can certainly weld some test pieces to see if you are getting the results that you are looking for.

Good luck

[Mike W]

You can download the manual for the Syncrowave 250. It has a chart for postflow.