AC to DC stick welder conversion

[mitchash]

Has anyone done the DC conversion on a older AC stick welder? I’ve seen a few videos on it. Wondered if I should try it on my Miller Thunderbolt?

 

[ewoz]

Has anyone done the DC conversion on a older AC stick welder? I’ve seen a few videos on it. Wondered if I should try it on my Miller Thunderbolt?

I did it many years ago to my Craftsman. I bought 4 stud mount diodes and mounted then on two roughly 2.5' x 2.5' sheets of copper. I noticed a difference. I haven't seen any of the videos showing how they are doing it these days.

 

[mitchash]

They are using a 300amp bridge rectifier. Looks like they cost just over $20. to $50.

 

[mitchash]

My brother in law just did one. That’s how I found out about the rectifier. Here is a picture of his. He says it works great! Welds 7018 really well.

 

[ewoz]

That would be a simpler way to go. If you can get one for $20 it would probably even end up being cheaper.

 

[mitchash]

I would like to build mine so I can go back to AC.

 

[mitchash]

My Miller Thunderbolt. My father bought this new back when I was a kid.

 

[ewoz]

I was able to switch between AC and DC with my setup. My rectifier assembly had plugs and jacks so that you could either plug the rectifiers into the welder or plug your welding cables into the welder. I would be concerned with junction temperatures of the rectifier assembly you showed, but if it is working it's great!

 

[grsthegreat]

guess i lucked out, as my Miller thunderbolt is already a ac/dc machine. i actually thought all the thunderbolt line was.

 

[kneedeep]

Mine is AC/DC

Thunderbolt