Nelson stud welder

[Cord]

Due to a stupid mistake I managed to shear off a hydraulic pump shaft. The pump isn't horribly expensive, but the broken piece is jammed inside a drive pump that's worth $4000. I can't grab the piece with a vice grips so I need to weld something on that I can grab. A nut is the first option, but I'm worrying about splatter contaminating the drive pump. There is a Nelson 450 stud welder for sale about 4 hours from me. I think this is a great solution and will give me a tool that might have a residential use for some other project. I thought about a body stud welder, but I don't know if the pins are strong enough. Does anyone have experience with stud welders? When using threaded studs, 1/2" and under, are the ceramic cups needed?

 

[Streetcar]

I have only used 3/4” or larger studs. The ceramic holder contains the molten weld until it cool. We can have splatter when welding studs

 

[fishdrivel]

I have never used a stud welder but all the stud welds I have inspected had splatter

 

[cwbyeng1300]

Maybe use a short pipe that will fit in the hole. Then use a 3/32 7018 welding rod inside the pipe like this -

 

[arkydog]

i would recommend a machine shop tig weld the broke end and extract the broken part. no splatter, heat eases the removal. tig is the way to go.

 

[mrmikey]

How are you going to ground the broken stud without going thru the drive gears or bearings?
As was said, go with a short piece of pipe, you can use that as your ground as it will be in direct contact with the broken shaft and the pipe protects the surrounding bore from stray strikes or spatter..........Mike