Couple welding questions

[fullmer]

Saw a stick welder for sale and said it was a 500 amp, what kind of welding do you do at that high amperage?has lanse or any one tried a welding test on
Metal that was cooled in water after welding does it really ruin the weld??
 

[Ted in NE-OH]

Maybe high amperage for gouging or cutting with a rod, can be done.
 

[Puddles]

I've had steady diets of splicing 36”x300# I-beams, run in excess of 400-amps no problem. I use to have a policy if the number on the welding machine didn't start with a 4, I'd walk right by it and grab another.

I personally wouldn't cool a weld in water, but have heard where a lot of testing is going on, the test people will cool mild steel test in water, with no ill effects.


 

[Welding man]

500 amp is just exactly what you need to carbon arc. As far as cocling the metal in in water. Depends on the metal,the carbon content and what the critical temp is for that metal and how hot it is when you cool it.Ever heard of heat treating, tempering and drawing? Ah the wonders of metallurgy.
 

[Stick welding]

A 500 amp machine will most likely be 3 phase and if it is single phase, will use more power than everything in your house and your neighbors as well. Generally it is a big no no to cool welds in water but certain types of metal it is OK. I know certain stainless steel benefits from being dunked while red hot.
 

[Puddles]

Oh I don't know about that! I use to get 500-amps out of this thing all the time, and the lights never dimmed!




 

[JD Seller]

Did some bridge welding in the 1980s. Some of the beams where 4 foot tall and had an inch thick web. We ran 5/16 rods at 400 amps to fill the vee on those big beams. All the welders where gas powered.
 

[Stick welding]

I think a diesel is about the only way I'd want to
run 500 amps. LoL The old SAE 400's with a 6
cylinder Continental were pretty thirsty.
 

[Stan in Oly, WA]

I've heard that it's challenging to weld out of position with big stick electrodes at high amperage. Was it, or were you able to do those welds in the flat position?

Stan
 

[Stick welding]

Had to be flat. Probably had a lot of iron powder in them.
 

[Puddles]

Stan in my line of work, we were almost never out of the swing radius of a crane, if so then the crane would move. The only way you will have any real production is to roll the beams, and do all the welding flat. Most projects we did, the iron was fabed in our yard on the Duwamish River, or our yard of the Puyallup River set on barges, and shipped to site.
90% of the iron on this project just west of the Bonneville Dam was fabed in the Puyallup River yard. All double 36”x300# beams, with double 24”x94# beams, setting on over a million dollars of 36”x 3/4” wall pipe bought in Mexico. This temporary work trestle was little bigger than a football field.




 

[JD Seller]

They where all flat welds as this was a new bridge. We did repair some older bridges and there we had to weld out of position on most of those welds. These we usually used 9018 and 10018 3/16 rods. Set the welder usually at 175-200 amps.

When we where doing those flat welds they sure created some heat. I sure pitied anyone that had to do them in the summer. We where welding in the winter. You kept warm.
 

[Fullthrottle]

I have (and use) a "vintage" Hobart G-600. It has a 2 cylinder Detroit Diesel. We use it to air arc (carbon arc cut) with. It works well and is pretty good on fuel. The amperage controls need replaced (bad contacts)so that you could weld with it. It's permanently set on Maxine now!!