Old Thunderbolt Works

   / Old Thunderbolt Works #1  

Tractor Seabee

Elite Member
Joined
Oct 5, 2011
Messages
3,902
Location
Port Orchard WA Kitsap Peninsula, West of Seattle
Tractor
Kubota BX25
Bought a Miller JB 25 Thunderbolt AC welder at a garage sale for $30. Lady said it was in the back of her garage and did not know where it came from. Had no idea what it was worth, said make an offer. She snapped up the $30. Miller still has manuals so down loaded one.

After sitting for almost a year here I decided to try it out. It works. The adjustment is stuck at 125 A but that worked for the 1/8 6011 project I had. Low and behold it works. Burned a couple pounds of rod. I now need to pull the cover and clean it up and see why the slug adjuster is stuck.

Did mill make a companion AC/DC 225 thunderbolt other than the XL series in this line? I read an article on the web about converting the AC to a DC. Has anyone done that conversion? Was it worthwhile?

Ron
 
   / Old Thunderbolt Works #2  
Ron,

I bought a new one in about 1980 when they were on sale. Right after I bought it, they started handling the same thing in an AC/DC. That's why the AC model was on sale.

Don't be afraid to take it apart and unstick the amp control setup. It's just a big thread that moves the coil or the iron core. My fan went out, so I bought a 220 volt muffin fan, made a simple bracket and it works better than the original.

I was unhappy that I didn't get the AC/DC, but I have made and fixed a lot of stuff with that welder, including building a trailer and building the structural steel for my house. It still works as good as new.

You can buy a hand truck and modify it to attach to the welder and hold the cords. Then it's much easier to move around. Make an extension cord that reaches from your dryer plug, or electrical panel to anywhere you might want to weld.
 

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