gas stays on for about 5 seconds after foot pedal is released?

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i recently bought a lincoln squarewave 175 tig and i'm learning with it, it's my first time with tig, and i've noticed after i'm done with a weld and release the foot pedal, there is still gas releasing from the torch for approximately 5 seconds, this can't be normal right?
Reply:Yes. It's post flow and is used to help protect the weld as it cools, and to help shield the tungsten as it cools down from atmospheric contamination..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:We don't sell Lincoln's, but the post purge you're describing is becoming more and more popular with producers. Some welders like it, some don't. It's meant to protect the weld. If you don't like it, there may be a way to kill it, but I haven't gotten around to checking. It won't degrade your weld, just might take some time getting used to.
Reply:On higher end machines, pre-flow and post-flow are adjustable.  The are on My Lincoln Squarewave.
Reply:i have an older model squarewave, is there any way to adjust the post-flow? what's bothering me is that if i just make a couple little tacks on something i'm working on the gas just keeps flowing out the torch long after i'm done, and i feel bad wasting argon like that... and if i touch the foot pedal by accident, gas stays on again, so it's irritating a bit
Reply:As has already been said, post flow is necessary for at least preventing the tungsten from oxidizing after the welding arc is completed.  In order for this to be effective, you should be holding the torch still during the post-flow stage.  This is not a waste, but rather, is necessary for producing high quality, contamination-free welds.It sounds like you haven't attempted to read the owners manual for your machine.  I'd recommend locating the manual, and familiarizing yourself with it because such basic questions such as how to adjust post-flow (if such an adjustment is provided) will probably be answered in there.
Reply:There will be a setting knob on your panel face that says POST FLOW  that is how you set the gas flow after the pedal is released.....I like 10 sec myself depending on the tungsten size.....It is the ONLY way you can get nice color on stainless or TI.....  Miller Dynasty 350Twenty Six HammersThree Crow BarsBig Rock
Reply:The 175 Square Wave has fixed postflow, fwiw . ..- Tim
Reply:thank you all
Reply:http://www.millerwelds.com/resources/TIGhandbook/Good free resourceEd Conleyhttp://www.screamingbroccoli.com/MM252MM211 (Sold)Passport Plus & Spool gunLincoln SP135 Plus- (Gone to a good home)Klutch 120v Plasma cutterSO 2020 benderBeer in the fridge
Reply:5seconds of postflow @ 15 CFH equates to 0.004 cuft of argon.  With a 125 cuft tank, thats only 0.003% loss.  Three-thousandths of one-percent.  Hardly anything to lose sleep over in this line of work/hobby.
Reply:Yep some welders you can set the time of pre and post flow. I keep mine set at 15 seconds
Reply:jonny  -  If you want the gas flow to end on measure, stop welding 5 seconds earlier  -  Opus
Reply:Originally Posted by tadawsonThe 175 Square Wave has fixed postflow, fwiw . ..- Tim
Reply:I've got the same machine, fixed post flow.  It even purges the line when the machine is initially turned on.  No way to change it on face of machine.  The only switches are for on / off, AC or DC,tTig or stick, and an adjustment knob for amperage.  I like my SW 175.-AaronJet 17.5" Drill Press1942 South Bend 16x84 Lathe1980s Miller 320A / BP --- 2013 Power Mig 2562012 Jet 7x12 Horizontal BandsawVictor O/A Setup