I have begun experimenting with steel. So far it's waaaaaay better than Mike Hummel's experiments. Oh man. First, I made a sand bag out of a pantleg. I got this idea from some research I did, and it works pretty well and I don't need a log. Thanks to a friend in fashion design, it is the best looking sandbag ever.
A ball peen hammer would probably be more effective, and a shallower curved hammer would be best.
First I did some test weld beads on a flat plane, they look nasty compared to real MIG welds, but I can see that with practice they can be strong and neater than before.
Then some tests joining parts. A corner weld and a butt weld.
Grinding and metal brushing the welds and metal surface clearly improved the look of the welds. It removed the discolorations from welding and smoothed out bumpy and lumpy welds.