Millermatic 200 Welding Amperage Range

[MinnesotaDave]

Welding up rust pinholes is not always easy. The problem is that you may have a tiny little spot where the rust broke through, but on the back side the metal is paper thin all around the hole. It can be many inches before you get back to full thickness metal. The beat thing to do is open up the hole until you have cut out all the cancerous metal and fit in a patch, then skip weld the patch in. It could be a nickel sized piece or it could be 30 square inches.

+1, I've run into this often.

The edge around rust is paper thin and rusty - cutting back to good material is mandatory.

[walker]

Btw, the only good magnetic ground is the one in the scrap bin. Just wait until it leaves a nice fat arc burn on your nearly completed project.

[MMW]

Do you have the proper liner for .023 wire? Using a larger liner will hinder performance. How long is the gun? If it is a 15' one it will also have trouble feeding .023 wire smoothly. The shorter the gun the better for .023.

The proper term is tack welds. You are trying to do a series of tacks to make a complete weld. A stitch/skip weld is a weld then space then weld etc. For instance, 2" of weld every 10".

[89vette]

I looked at the Mig Gun last night and there are no model numbers on it so I will
contact Tweco today and see if they can help me figure out which liner to use.

"The problem is that you may have a tiny little spot where the rust broke through, but on the back side the metal is paper thin all around the hole. It can be many inches before you get back to full thickness metal." I think this is exactly the case, was hoping to get away with welding up the holes since the panels do have a crown and I will have to hand form the patch panels, which I have never done.

The reason I was using the magnetic ground was I wasn't sure how much the panels are actually connected due to seam sealer, spot welds etc., but I never did just try it, I started right off with the magnetic ground.

The gun cable may be 10' to 12' feet long and is not the right liner for .023, it had .035 in it when I got it.