View Full Version : Not really a stupid question, but kinda

07-09-2006, 01:55 AM
I have a 135A welder. It has done everything I have needed it to do so far. I keep reading that you need to have bigger welder to do thicker metals. I have no visions of me welding 3/4" plate with my welder, but I have welded 5/16 with it. Is there a problem with using a smaller welder for thicker pieces using multiple passes?


07-09-2006, 07:23 AM
Well if it works it works man... but I would be vary cautious about how safe your beads are with the thicker metal...

07-09-2006, 08:20 AM
for small hobby projects there's no problem, a very skilled welder can make critical welds with a small unit, however, many of us on here do not have the experience to safely do this.
can you weld a table with it yes, can you weld a trailer with it yes (but i wouldn't) a small unit is best suited for small jobs (tubing,sheetmetal), you need more current/heat for thicker material, especially anything structural or safety related. can it be done yes should it be done no

07-09-2006, 09:52 AM
:) I have a Miller Cricket XL.......90 amp at 20 % ..it is my first mig welder. I bought it used. I am really
impressed with what it can do. I have welded 1/2 " round cold steel to
1 1/2 x 1 1/2 x 3/16 angle . That's a lot to fill where they meet but it did it. Would I try the same thing in the middle of a 36" x 36" sheet x1/4 "........no.....I would probably loose my heat too fast. If the joint was prepaired properly I see no problem putting 2 pieces of
5/16" together. It's all about keeping it hot. When the newer Miller welders started coming out like the 130 I thought about upgrading untill I read the specs. Still put out 90 amp at
20% duty cycle. I think Miller and Lincoln had a war on who could put the larger number
in their model number.. kind of like air compressor mfgs and their claims. Now my 90 amp Miller is running .023 and used on body work and if I ever need to go to the field. It still works great!!!!!!

07-09-2006, 10:32 AM
back in the gokart days we kids had a little red welder , and of course we found it's limmits early on .... then we realised multiple passes were fine accept that the initial passes down below were nowhere nere adequit in penitration.....so we started using a propane torch , to get the region to be welded as hot as we could get it ....then our initial passes showed much better penitration , and our welds were good

if you build a three story balconey , may want to get a welder -proper!

07-09-2006, 11:10 AM
Based on Hobart's door chart, small MIG welders up to the 140 amp class are suitable for 1/8 steel and below with solid wire and C25 shielding gas. Can you use straight CO2 instead? Sure, if your machine has an extra 2 load volts available. But you don't, so you have to decrease the WFS (amperage) to obtain a stable arc and you end up with less weld power.

Hobart claims up to 1/4 with flux core and the Hobart Competitive Comparison chart states that welders in this amperage class should not be used on 5/16 steel. From the statement that 5/16 is not recommended, I infer that 1/4 is marginal, and 3/16 is probably the practical limit.

But this is all hypothetical and personal opinion. Opinions are like... (you can fill in the rest ;) ) The only true way to decide if a machine is capable of producing a good weld is to test it and prove it...


07-09-2006, 11:25 AM
Hey, Monte: My first MIG was a Miller Sidekick 90 amp, and it was a sweetheart!:)

07-09-2006, 11:38 AM
There are simply some things that can't be done with a 110 volt welder.

Yes Preheat with propane helps, and I use a weed burner all the time.

Having said that if you don't have the experience to know where to draw the line, especially on a critical, or structural joint, you'd better go by the manuf. specs on the welder capability, or work with someone more experienced! (second option being good in either case!)

07-10-2006, 10:39 AM
Thanks for the replies.

I have always had access to an old red buzzbox, so that's what I've used when I needed to weld something structural that was too thick for my small welder. Good information to have though. Thanks again.


07-11-2006, 03:39 AM
I have read some and looked at charts and I'm confused, or maybe I'm not; I can't tell. (Or maybe that's just the way I am.) According to most of the charts I have looked at, thicker materials require thicker wire. Does that mean that thicker wires run hotter? I have always used 0.035 because, well, that's what I keep buying, and it has worked fine for me on sheetmetal and everything else I've welded. I am getting ready to buy another spool of wire, (after reading a few threads here, I'm thinking of ordering some HB-28 from Cyberweld) and want to get what should work best for me. (I know that's a very vague statement. Sorry.)

I've also been fighting porosity. Can that be related to the wire quality? Know what? I think I'll take some pics, if I can find the camera, and start another thread.