Hi Richard, thanks for signing up and thanks for your question.

On carbon steel, there is a pretty wide range of flow rates that will work without giving tell tale signs of not enough or too much gas flow.

but when you have too little, the puddle might start to spark a bit, the tungsten can erode, and you will probable see the puddle bubbling and showing porosity.

too much gas for a giving cup size might cause hard arc starts and might also actually draw air into the argon causing some of the same symptoms as not having enough argon flow.

since there is quite a wide range in between, using more argon than needed will still work but just wastes argon .

hope this helps,

jody

I would go to the chart and make sure you start with recommended settings for the gas you are using and for .030 wire.  The recommended wire speed for .030" on the chart is most likely a bit too high so I would reduce it by 10% to start.  Then its just a matter of welding some beads on scrap to dial in the smoothest arc for the application.   hope this helps.

jody

Matt and I did a talk on pulsed MIG a while back  https://welderskills.com/programs/pulse-spray-zoom-edit   

We can definitely do another one to cover some of the topics you listed

thanks very much..and to echo Joeys comment... Let us know if there's anything we can do for your students!  happy to do a zoom call 

thanks for the insights, gives me an idea for next time

We keep learning.  thanks Martin

you will notice a big difference in arc starts using either 2% lanthanated or CK LaYZr and the tip will hold up much better

thank you Eric, Sam always brings value

thanks Martin, Sam had a lot of great tips that I hope help a lot of folks

Yes I would say that is a fair assessment. using this type of angle seems to help the metal flow better.  Not sure what physics are behind it.

In certain situations, I would recommend not using nearly this much angle but it does seem to work well when weaving with tig on steels.

thanks