How much current to weld 5/8" thick aluminum

[nc5a]

I need to repair my Cuttermaster tool and cutter grinder supports bracket. I have a Lincoln 255 Square Wave and a 230 amp water cooled tig torch. Would I have much of a problem welding 5/8" thick aluminum? The thickest aluminum I've ever welded was 5/16". If the 255 Square Wave and 230 amp torch will do it what procedure should I use? The largest tungsten I have is 1/8" and I assume it won't be big enough so what size should I be using? Thanks in advance.

Ron

[Tungsten dipper]

You have all you need to weld that. I would vee the crack out . Clean with acetone, then clean the oil out of the threads. I would pre heat in oven and would try 180 amps ( you are not welding the whole 5/8"). If it doesn't puddle in a few seconds try a bit higher amps. Then I would put it back in the oven to let it cool slowly. Be sure to back off the pedal slowly at the end of your welds to prevent cracking.
When you start your welds look for contaminants, if you find them clean again.

[nickel-city-fab]

You can do it with what you have, using settings that you are used to. I would go maybe 200 amps, vee it out real good first. weld from both sides and go multiple passes. I like to clean with soap-water and a stainless brush directly before preheating with a torch. And clean thoroughly in between passes.

[danlb]

Good advice so far.

A good place to start is one of the online calculators. https://www.millerwelds.com/resource...ng-calculators works well. It shows suggested electrode, number of passes etc.

[nc5a]

Thanks for the tips. Miller's online calculator says it should take roughly 300 amps for the root pass then less and less for the remaining 4 passes. Danlb thanks for the link to the calculator. I had no idea there was such a thing as a welding calculator.

[strokersix]

You may want to clamp some quenching mass on the small piece to help balance the conduction out of the weld zone. Just a thought. I have only minimal aluminum welding experience.

[BigMike782]

1/16" E3 or ceriated tungsten, Syncrowave set to kill, DC and straight helium and thing is putty in my hands.

[larry_g]

I am not a weldor so for a second opinion; I would mill off ~1" off the bottom of that casting and bolt on a steel bar that would bring it back to height. Does the casting material cause one to ask if it is weldable at all? Once welded up there is the issue of getting the threaded hole back in there. Do you weld the current hole up solid and make a new one or try to salvage what you can of the current hole?

lg
no neat sig line

[dbq49er]

How or with what are you v-grooving the aluminum? I have only used a SS bush on aluminum for cleaning NEVER a carbon product.

[Tungsten dipper]

How or with what are you v-grooving the aluminum? I have only used a SS bush on aluminum for cleaning NEVER a carbon product.

A carbide burr.

[danlb]

Is carbon contamination that much of a problem? I've welded aluminum after milling. I've gone so far as to grind the bevel on a belt sander that had also been used to clean up steel burrs, followed by brushing with a SS brush. I don't always have great welds, but very often I'm welding parts that are made of an unknown alloy.

So do I need to be more careful about using only purest carbon free tools on an aluminum edge that I'm going to weld?

Dan

[Tungsten dipper]

Is carbon contamination that much of a problem? I've welded aluminum after milling. I've gone so far as to grind the bevel on a belt sander that had also been used to clean up steel burrs, followed by brushing with a SS brush. I don't always have great welds, but very often I'm welding parts that are made of an unknown alloy.

So do I need to be more careful about using only purest carbon free tools on an aluminum edge that I'm going to weld?

Dan

I worry more about aluminum oxides from sanding discs, and brushing back and forth with a stainless brush ( should brush in the same direction) that I do a carbide burr or steel end mills. I also use acetone on the work and filler rod too.

[danlb]

Thanks TD. I'll try to keep an eye out for the grade and type of sanding grit on my sanders.

Dan

[garyhlucas]

They make grinding wheels for a 4-1/2" grinder specifically for aluminum and stainless. They work really well and don't clog up.

[Fonzy4140]

I would suggest you pre-heat weld area at least to 250-300 deg F will help get the welding started, along with the other comments you have all you need to do the job.