TIG & CRS discoloration, normal? Advice requested please.

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I am fairly new to TIG welding having had a total of one formal day of training along with many hours practicing out in my garage. I just completed a project of making two very strong shelves for the bottom of my modular welding table but think that I could have done a better job.  The shelf material is 12 gauge sheet CRS, and the shelf "supports" that I zipper welded to the bottom of each shelf are 1" by 1/8" CRS. I used CRS because I did not have any time available to remove mill scale and the shelves will be powder coated by a good friend of mine. I did thoroughly clean all of the metal with clean rags and acetone prior to welding.My welder is a HTP Invertig 221 and I used the following settings:foot pedal controlled 17 series water cooled torch#8 cup with gas lens3/32 2% lanthanated tungsten point sharpened with clean diamond wheelDCEN set to 140 amps maximum100% AR at 20cfh, 2 seconds pre-flow, 6 seconds post-flow3/32" ER70S6 filler rodThoroughly cleaned and dry CRS materialWhat I am concerned with is what I consider to be large areas of discoloration around each of the welds. It was extremely humid outside when I was welding, it was actually thunder-storming while I was working in the garage. I did my best to prevent contamination, but are these discolored areas normal or would a change of settings or technique prevent them?  The discoloration was easily removed using a stainless brush wheel in my air die grinder.Also below are a couple examples of my welds, they are far from perfect, but I've made a lot of progress over the last few months.  No, I won't post photos of some of my earlier welds, but I think you probably know what they looked like.Thanks in advance for your helpful comments.
Reply:Good choice on starting with CRS.   The discoloration your cited and evidenced in your photos is common.  Expected.  Natural side effects of HAZ progression/attenuation from the weld line.  The welds looks nice with good fusion and toe wetting. Also, the surface area of each HAZ looks consistent and near-identical.IMO, cost of doing business with TIGn on CRS or HRS.  Acceptable. What should matter from your perspective is controlling the overall warpage of the table surface and the as-laid quality of the welds.  The net color of the HAZ adds character.  For a variation on the theme, you can also "offset" the fillets by spacing them apart for a given line instead of back-to-back.  Think HAZ half-moon patterning.Other TIG pros here can opinionate based on their experiences.Last edited by ManoKai; 08-01-2014 at 08:03 PM."Discovery is to see what everybody else has seen, and to think what nobody else has thought" - Albert Szent-Gyorgyi
Reply:Originally Posted by ManoKai ....Other TIG pros here can opinionate based on their experiences......
Reply:Like Manokai said, the color is normal. It does look like the affected area is a little large (too much heat). I see you set the machine to 140amps, did you use all of them or just use part of the pedal? Try a little higher amperage and move faster, when you see it wet in you move. If you are able to reduce heat input with more amperage and speed you will notice the colored area gets smaller and you should get less warping also.Airco Ac/Dc 300 HeliwelderMillerMatic 200 (stolen)Miller Maxstar 150STLMiller AEAD200LE (welding and generating power) Hobart MIG
Reply:Thanks guys.At 140 amps I rarely had the pedal bottomed out, so most likely running between 110-130 amps.  I'll try more amps and moving faster the next time I practice. I was originally going to use 16 gauge steel for the shelf, but practicing on it showed that warping was going to be a problem for me so trying to move faster might really help out.
Reply:The hotter/tighter arc/faster you can go, the less warpage/smaller HAZ (coloration) will occur. This takes skill, it will come with practice. Ask a helper or use camera/phone to get actual reading of amperage. Keeping an eye on voltage will tell you how consistent your arc is.Constant Current Weldor.
Reply:I finished my shelves, turned out perfectly.  See HERE.