Thanks for the replies. I"m using the standard 75/25 argon/co2. The steel was new, bought from the supplier today. We sectioned a fender (older US steel) earlier and had absolutely no problems with the welds, penetration, appearance all what it should be. I used a flap wheel to clean the new metal followed by automotive wax/grease remover as I"ve done numerous times before. Always had good results.
From sources on the net there is an indication that Chinese steel composition is not quite up to US standards. Unfortunately they didn"t describe the effects when welding. In another article there was a complaint concerning steel being used in the Bay bridge in Ca being inferior and causing some concerns for safety.
I suppose I"m grabbing at straws trying to figure out the problem (s) so I can get some good welds. Guess I"ll keep trying. Thanks again.