arc welding amps

[jools1010]

Hi all, new to arc but used mig before, my question is regarding metal thickness with arc welders.

Been looking at 300 amp welder with a stated max of 12mm then found another at 500 amps and stated the same max of 12mm.

Whats the max thickness I can weld with a 300amp arc welder?? Also would this 12mm max sugguest I can weld a 90 degree Tee joint with two 12mm sections or two 6mm to give a total of 12mm

Also many have a chance of a 9-10 Kva generator would this run a 300amp arc manual on welder states 9Kw input.

Many thanks

Jools

 

[wyn]

The amperage will only realy tell you what size rod you could use on the welder.
If you used multi runs you could probably weld anything up to a couple of inches thick with a 200 amp welder or less.

What sort of stuff are you looking to weld ?

With the generator the general opinion is you would need at least 3 times,or maybe 5 times the power of the welder so 27 -45 Kva

 

[jools1010]

arc amps

looking to do a bit of mobile welding as I've alway been asked by friends and work mates.

I thought I'd get the biggest I can afford for arc welding only mentioned the 300amp arcs because 12mm thickness was stated in a broucher I have.

Iam starting an arc / mig / tig course in sept I can mig ok but no experience with arc / tig.

I can get 200 amp welders for good money Iam I correct to say that multi runs will be ok for 25mm, I thought of looking for welders with single pass max thickness, is this not the case?

thanks

Jools

 

[shenion]

Most mobile welders I see around here have 225A to 250A welder/generators. I am seeing more with Arc/TIG/MIG capability.

You would not want a separate welder and generator as the generator will have to be huge to run a 200A arc (probably 15KVA, minimum,) 300A twice that.

 

[wyn]

I can get 200 amp welders for good money Iam I correct to say that multi runs will be ok for 25mm, I thought of looking for welders with single pass max thickness, is this not the case?

200 amps would be a pretty good size.

The single pass thing would probably be more important on welding very large stuff. The rods would probably be 6mm + as well.

Multi runs would be fine for stuff up to 25mm with a bit of prep to the plate.

 

[jools1010]

arc amps

Thanks for replies.. I almost bought a portable geny and arc welder so the hunts on for a welder generator.

Good to know I don't need hugh amps to weld 25mm stuff..

Thanks again

Jools

 

[wyn]

I have a chinese welder/generator 180 amps it was around £500 new.
It does the job ok 4-5 hours at a time with 3.2 rods.
It won't realy run a 9" 110v grinder but 240v no trouble.

 

[jools1010]

arc amps

Cheers Wyn, thats a good guide the only thing I'd want to run is my 2hp compressor.

Jools