Gas Welding Problem

[themodernartist]

Howdy,
I've have some A/O welding problems and don't know whats causing this.
I am in the process of welding up 3 pieces of my rear fender panel by gas welding using the no gap, no filler rod technique as per David Gardiner. My problem is that when applying the torch, the molten metal is FOAMING UP and gets unmanageable as to it's flowing characteristics. The visual appearance while doing the weld is like that of bubbly molten lava coming from the volcanic lava flows. Its all foamy and crusty once it cools.
1. I previously practiced doing this on scrap pieces of the same gage and type of sheet metal until I felt comfortible with it and having good results with the metal flowing beautifully into each other with good HAZ characteristics. This method came quite easily for me.
2. I had only wire brushed the area to be welded before I started to weld but then had the problem.
3. I went back and disassembled the 3 pieces of metal which have/had no paint on them and washed area thoroughly with clear water, then washed with lacquer thinner, lightly sanded all areas disk sander and then wire brushed with wire wheel, and run sandpaper along all the edges for good measure. Felt that should have done it.
4. Started welding again with similar results but maybe a little less of the foaming up. I still couldn't get the pieces to flow into each other as I had done with practice pieces.
5. I was using the same torch, same tip, same size flame and same pressures on the regulators.
6. I got so frustrated I took our my MIG welder and tack welded everything together just so I could calm down. I still want to finish the complete weld using A/O if I can solve whats causing this problem.
7. I can't show a photo of it since it only happens during the welding process.

Any ideas?

Peace,
Chaz (the other one)

[anders nørgaard]

Chaz,

If you had no problems welding the metal with the MIG, it's not the metal that is the issue. You MAY have a setting on your O/A flame, that is "over oxydiced"... uhm.. surplus of oxygen That will cause a cutting flame.

[themodernartist]

Thanks Anders,
I sort of thought that may be the problem but you know when you are in the middle of a stressful problem its difficult to keep your cool thinking.
Peace,
Chaz (the other one)