Gas settings!

[Unidentified]

Hi guys I've been struggling for a while getting nice consistent welds on stainless and have tried so many different settings to no real avail! I've just purchased a gas pea shooter to measure my settings and it was way higher than what anyone else seems to run ie: 20 L/min so have backed it down to 6 L/min
but this has made no improvement to the colouring and the weld just has a burnt look like excessive heat or as other people have mentioned too slow! I want to eliminate the gas settings 1st so wondered if anyone no's is there a disadvantage from running too higher gas?

Forgot to say this is on 1.5mm tubing if it makes a difference!

Thanks
Ben

 

[Paul.]

Your 6lpm will be ok for most jobs, too much gas flow can pull in air from behind the torch particularly if the torch angle is too low, to determine whether you have a gas problem follow the instructions for a spot test in this post http://www.mig-welding.co.uk/forum/threads/just-got-a-new-tig.27276/page-2#post-301703

the rest of the thread is worth a read through as well staring at post 13, http://www.mig-welding.co.uk/forum/threads/just-got-a-new-tig.27276/

once you're sure that the gas is working properly then double check your settings, around 45 amps for 1.5mm, use a 1.6 tungsten nicely ground as per the tutorial http://www.mig-welding.co.uk/wiki/DC_Electrode_Preparation,

Use a 1mm filler rod, this will let you travel a little faster, thicker rods take more power to melt and cool the weld pool

Not too much electrode stickout, 5 to 7mm is normally enough, and keep the arc length short, post gas should be long enough to protect the electrode while it cools, an oxidised electrode is a sign of a gas problem or insufficient post flow

Welding round a tube is likely to cause you gas coverage problems because of the quickly changing angle of attack, keep the torch quite steep to the weld and learn to rotate the wrist to maintain the angle, do a few "dry runs" to teach your muscles the technique, you may also be dragging oxidation from the back of the weld, very easy to do with butt welds on tube and one of the reasons why we purge

 

[Piero]

Very good and informal reply tig paul

 

[langy]

I get by with 4 no problem

 

[Unidentified]

Hi guys thanks for all your help and advice I've tried dropping gas right down to 4 and up as high as 12 but found no real improvement in my welds so I've left it at 6L/min a and now trying to switch settings to help but regardless of power settings they all look like I've way too much heat! I will snap some pics and try to upload over the weekend and see if you can see any reasons for this!

Sorry for so many newbie questions but I've had days of tweaking settings and not really making any head way on this, I'm not expecting to produce A grade welds over night but if I could see some signs of improvement I could at least start to make sense of what's happening!

I will write the machine settings next to the relevant picture to help make sense.

Regards
Ben.

 

[backpurge]

It's nowt to do wth your gas flow, your welds are simply getting too hot so travel faster/add more filler/turn your amps down/shorten your arc length. It's all down to practise, don't get disheartened it will all fall into place eventually