Welding RSJs

[Supervit]

Hi,

Just a quick query regarding welding Structural steel. What sort of Mig welder would be required to weld 10mm plates to universal beams? I got talking to someone on a building site and he was claiming that his welder was capable of such welding (110A). I wasn't convinced so thought I'd ask those in the know

Any feedback would be much appreciated

Michael

 

[grim_d]

Would stick not be more suitable for this? A 110A MIG is not going to be welding 10mm.

 

[Wozzaaah]

I expect he's using an MMA (stick) welder and welding using a multi-pass technique. A 110A mig welder would barely tickle the surface.

 

[Welderpaul]

I think he's talking rubbish Michael. We weld that sort of stuff most days and use 500amp migs. Probably get away with 250ish amps for a mig. Thing to remember is that a 110 stick/mig welder is likely to have a very poor duty cycle running at top whack. I.e it wont work for very long until it cuts out to give itself time to cool down.
Welcome to the forum.

 

[Supervit]

Thanks for the quick responses, I thought he was talking a load of rubbish. Sounded more like a recreational welder than anything else. I only use our mig for my off roader and know the limits of that

 

[bawjaws]

mabee the guy was talking about the input voltage?, 110 for most site work...

 

[Hitch]

Our cheapo 110v stick set works alright for 10mm. at full power (150a) its 100% duty cycle.


A 110a stick machine would weld end plates on a beam no hassle.
A 110a mig setup would just about be adequate for a bit of 2mm sheet.

 

[Tigman]

My inverter is 130amp Thermalarc will weld plates to beams no problem , I would set to about 110 amps tops for fillet weld , multi pass , 3.25 rod. Never had any problems with this