[8man]

I have read on Garage Journal a post by MP&C on "how to weld thin metal", specifically what you are trying to weld.

He uses a tack about every 5" +/-. Stops and uses a cutting disc to remove the proud part of the weld. Then when it is smooth like he likes it, he does another tack next to the last over and over until the entire weld line is complete.

Going slow like this will help control heat. Another guy keeps his air hose next to him when doing this. Every once in a while he shoots the weld area with air if he thinks it is getting too warm for his liking.

The area you are welding should be a little more forgiving than say when you replace the bottom of the door and have a long run on a straight piece of sheet. However, you are wise to be concerned about the heat build up and should take precautions.

Where you are welding, you have had a rust through. If you look inside, you may see that there is other metal that has pitted over the years. This pitted metal, when trying to weld may give you a blow out even if all else is set right. I can't speak to what others do, but I slow way down on the blow out, let it cool and start spot welding it in until I fill it back up.

You are right about the gas versus the flux welding. It would be better, but you can do it if you take your time and watch closely. If you think it is getting too warm, cool it down, or stop for a little bit. Patience is your friend when doing this.

If you want to be really cool, check out oxy/acetylene welding. THAT is the way to go, it is at least as good as MIG, some say better.

Now, if you think I'm doing all this, you would be wrong. I am trying. I am getting better at the patience and taking my time and keeping to the spot welds and working each then doing it all again. I can say that when I do, I get much better results.

That's what I think. I'm sure others will have their input as well.