I bought a bunch of 2.5" flat cold rolled steel of various thickness. Cut it up into 4.5" length's. Anytime I forget to weld or need to try something out, I can grab a couple of pieces and get a little practice before I commit to burning holes in something. :roll: Great for dialing in vert...

"C" look the best. Did you remove the mill scale??? Make sure your work clamp is good and tight against clean shiny metal. If it isn't you will a lot of inconsistencies in establishing good quality welds.

20 lbs of CO2 goes a long way. Since it is a liquid, it evaporates to make 175 cu/ft of gas or about 8.75 hours of weld time. (20 CFH).

Just for giggles.
20 CFH = 9.44 LPM.
I have found my setup runs nice when dialed in at 10LPM. .030 C25 mix.