Welding Practice, What Guage Steel?? Options

[74914LE]

Starting my practive sessions to get the welding down before I
get start on the Hell Hole, and wanted to see if anyone could give
me the answer to the question of what is the correct Guage and
Type of Steel to use? Based on my search of the threads, it looks
like both 18 and 21 Guage are used, but want to make sure. I will
be ultimately fabricating my own patches or buying the preformed
pieces.

Thanks,
74914LE

[tat2dphreak]

QUOTE (74914LE @ May 6 2005, 09:57 AM)

Starting my practive sessions to get the welding down before I get start on the Hell Hole, and wanted to see if anyone could give me the answer to the question of what is the correct Guage and Type of Steel to use? Based on my search of the threads, it looks like both 18 and 21 Guage are used, but want to make sure. I will be ultimately fabricating my own patches or buying the preformed pieces. Thanks, 74914LE

what I would/plan to do... cut a little piece out so you can know exactly what's at THAT spot... take it to the metal place and say "I need something this thickness, this is what I'll be welding to" ... they know their shit...

[Maltese Falcon]

If you're using a portable MIG with say a .20/.25 wire, you may be ok with 20 ga.
A more hotter prof. machine with a .30/.35 wire likes 18 ga. You may be torching thru your thinner metal with a hotter machine. The smaller machine on 18 ga. may leave you with lots of cold welds and clean-up grinding to do.
A lot of tecnique is needed here--practice on some scraps first ! (IMG:http://www.914world.com/bbs2/html/emoticons/idea.gif)
MF (IMG:http://www.914world.com/bbs2/html/emoticons/welder.gif)

[riverman]

I'd practice on 18ga. Once you can do nice welds on the thin stuff, the the thicker guage becomes easier.

Having just finished a bunch of patching like you're just starting, I can offer a few tips I learned along the way. For thin gauge welding with a 110v gas MIG, use the lowest power setting and a fairly low wire-speed. To get nice penetration you have to hold the bead in one spot for a certain period of time (you'll have to practice to find out what this time is), but one millisecond longer and you'll get burn through. I found that the easiest way to make nice strong welds with least amount of experience is to do a series of tack welds along the joint and then join the tacks with a whole bunch more tacks, one right beside the other. You'll end up with a complete weld that will be a little bumpier than a straight pass, but you will be confident that it is a strong weld. If the weld is in a highly visible spot, you can grind it smooth pretty easily.