Sucking oxygen into a weld by turning up flowmeter?

admin

So I was talking to a guy at my local airgas store and somehow we got on the discussion that if you were to turn up your flowmeter while welding aluminum to much that it will create a type of small vortex and suck oxygen into your weld. Is what I hear true. Also can it happen on not just aluminum but stainless or steel either. ThanksAs said by CHENRY:you cant weld on a thingamajig like that. are you even certified to do thingamajig welding ? I once saw an improperly welded thingamajig fail and eleventy twelvoteen things got ballywhacked. I dont think i would risk it.
Reply:I don't think its oxygen that gets sucked in it's more like "atmosphere"Yes too much gas flow will result in the described description.....zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:Yes it's true. The higher velocity flow thru the nozzle cone, can pull air into the gas stream, then mix it with the molten puddle.In TIG, the normal cups, also do that quite readily, which is one big reason for using gas lenses--which (if using lower gas flow rates), slow down the gas stream and spread it out for better coverage.Blackbird
Reply:Basically what happens is if your gas flow is set too high it comes out of the nozzle very fast and can bounce off of your plate, once that happens you are sucking in the surrounding atmosphere, which 20.5% of is Oxygen. I don't always trust what the flowmeter or reguator is saying, and will use a flow checker at the nozzle to verify correct flow.
Reply:Originally Posted by ss42768...I don't always trust what the flowmeter or reguator is saying, and will use a flow checker at the nozzle to verify correct flow.