[Joe]

I am practicing my TIG welding a little each day. I'm beginning to get used to the torch and machine. I am getting holes in my practice welds and I'm sure one of you guys can tell me what I'm doing or not doing. I'm just welding on mild steel at around 80 amps with a 3/32" 1.5% lanthanated tungsten that has been tapered on an 8" bench grinder. The machine I'm using is an everlast inverter powerpro 205 using DC, switch on 2T, ground is +. I think that the bead on the flat bar was just done without trying to add any rod. The edge weld was me trying to add E70S2 rod. This is my first attempt to get pictures to the forum, so bear with me if they don't work.
joe

[gurew]

contamination

which can come from 2 things pretty much...

1 the metal is dirty (clearly looks as though you didnt clean the metal....your steel prep should be shiny silverish in color..esp on hot rolled steel...so prep it so its shiny

2) gas...either not enough gas flow OR!!! way too much for the gas cup/lens size (can suck bad air in the argon flow)

my guess is that if you prep your metal those issues will go away

[Joe]

okay, I'll clean things up and try again.
Anybody know of any tables giving gas flow versus cup size? I was using a #7 cup and gas flow was set for about 10lph. The everlast flow meters are in liters.
thanks.

[Gary]

Joe ,
cut your gas down to between 5 and 7 lph 10 is getting too high and might be getting blown away with too much flow.
The off color area looks like gas coverage.Both welds show that brown haze around that indecates gas coverage. A #7 cup is OK but I usually have a #6 on mine , It looks like low amps and bad gas coverage to me.Also like gurew says clean the metal , TIG welding needs clean metal to get good fusion since the only thing covering is the gas only not using any type of flux like mig or stick.
Gary

[Polaris_Dave]

Are you doing this outside? or with your shop doors open?
Just curious...

[jakeru]

...
Anybody know of any tables giving gas flow versus cup size?

I printed out this page showing cup size and shielding gas flow rates for various welding current, tungsten sizes, and other variables, and keep it near my welder for quick reference:
http://www.ckworldwide.com/tech-3.pdf

I find having the info nearby the welding machine to be quite handy. It is published by a manufacturer of TIG welding specialty products, such as tungstens, cups, TIG torches, etc. I have found that it almost always agrees "spot on" with the recommendations I read about on the web from various successful/reputable welders.

The whole version of the "TIG welding specifications: document is also worth at least a quick read also:
http://www.ckworldwide.com/technical_specs.pdf

[Joe]

thanks everyone for the good advice. The pdf on gas and cup size is especially helpful.
I was doing the welding inside the shop out of the wind, but took the pictures outside for the light.
I'll try these ideas over the next couple of days and see where I get.
joe