View Full Version : Welding sheet metal please help
10-27-2007, 09:16 PM
I am trying to weld 22 gage sheet metal with a Hobart 140. I am using Argon CO2 with solid .030 wire. It keep burning through and making big holes. I have turned the the amp down and the wire up. Nothing seem to be working. Suggestion welcome. I am new at this!!!!!!!!!!!
10-27-2007, 09:25 PM
don't try to run a bead.....use some copper bar or pipe hammered flat to dissipate the heat ... don't be afraid to use tap # 1.... turn the wire speed down.... up makes it hotter.... some 0.023 wire would help,but 0.030 will work also... move your tacks around and allow the area to cool down before going back..... also some pieces of angle tacked to the sheet will help control warpage....
10-27-2007, 09:32 PM
hey there. you need to switch to .023 wire. you'll just burn through with .030. it takes more amps to melt .030. you'll need the correct size drive rolls and tips. read the info and watch the video half way down the page on this site for a technique to use when welding thin sheet metal:
read the info and watch the video on this page for an explanation of how to set the wire feed speed:
i basically do the same with my setup. .030 for most everything. when i want to weld something thin, i switch the drive rolls and tips and put on a roll of .023. works great.
hope this helps.
10-27-2007, 10:17 PM
023 would make it easier but I can weld sheet fine with 030. The "amps" is the wire speed. The volts should be turned down. Look at the chart on the machine, turn the volts and the wire speed down. More wire makes more heat.
10-27-2007, 11:01 PM
Well, Derek, you picked probably one of the most difficult applications to learn on, so don't feel bad about blowing holes through it! Everything said is true, and I do use .030 now, but it took a lot of practice to get here. Little tiny "dots" will be the easiest to get going. Forget beads on 22 gauge until you've been doing sheet metal for quite a while. The copper works (I just get a plumbing fitting and flatten it in my vise with a "L" shaped piece of 1/8" rod inside to use for a handle), but what really got me going on 22 was using a piece of backer cut from the same material...it just stays there welded in place, as opposed to the copper, which comes off. No replacement for practice! I actually like middle speed setting and #1 on my HH180. Slower wire speed doesn't seem to give me the same control as the "50" does. If I'm going to do a lot, I'll put a roll of .024 on, but usually don't bother, but when I do, I use ESAB Easy Grind. I sometimes use Harris "20 Gauge", but its a.030 wire that acts more like a .024...but usually just Pinnacle (Thanks for that tip, DDA!) .030.
Little dot welds...but get penetration (make sure they don't pop a part)! Practice on scrap...plenty of scrap! :)
10-28-2007, 02:04 AM
Lots of good info, and there is yet another technique I have used on occasion...what you need is more filler, while keeping the volts/amps on our low setting...the way to do it, is to add a filler rod, say 1/8", and feed into the MIG arc in squirts, or dot welds...the added filler will cool down the puddle and make it easier to deposit the weld metal. I don't think I would recommend this for a novice, tho...nevertheless you can practice this technique and have fun with it.
I have also used this technique for filling gaps, produced by a hungover fitter...even to sticking a nail or two into the gap. :D
This will be a repeat of others.
You'll help yourself greatly, by removing that roll of .030, and installing a roll of .023. With the wire speed dialed in close to properly, voltage tap #1 with an .023, Hobart HB-28 being my preference on this unit, produces a extremely soft arc that I find is very difficult to produce burn through with on a butt joint constructed out of 22 ga. This is especially true, when using the pulsing gun trigger technique.
10-28-2007, 11:16 AM
"I have also used this technique for filling gaps, produced by a hungover fitter...even to sticking a nail or two into the gap."...
10-30-2007, 08:37 PM
I recently welded new wheel arches to my truck using .024 wire, it was my first project. This is how I learned to deal with holes: keep depositing dots around the circumference of the hole. Eventually, as you build up a greater mass of metal, it becomes easier to deposit the subsequent larger ones w/o the heat burning through any more. Finally I can fill things up, albeit I have a lot to grind down.