requesting help troubleshooting a welder

[billyO]

Hello all, last fall I was given an old (late 50's?) Marquette gas powered generator/AC welder with an Onan engine.  I've got the engine running pretty good, and now is time to learn to stick weld, but am having trouble starting/running a bead and need some assist on what to change first.

I think I should get some new rod to practice with, and think that should be my first change.  I was given some 3/32" 7018 rod from a friend.  It's not been protected from the atmosphere, just laying on top of his forge,  I also don't see an AC designation on the rod.   

Or should wait until I get someone here who knows how to weld to see if it works and tuned properly.

thanks

[Herb Upham]

First a few questions ...

1. is the power/weld change-over switch in the weld position ... depending on model it is under the generator cover on the left hand side

2. is the throttle in the weld position and the govenor set for 3600 RPM

3. please attach a picture of your "bead"

 

I had one of these and used it for years ... I had to re-wind the generator field once when one of the brass screws broke and shorted part of the change-over switch. You need to make sure the field brushes are in good shape and the commutator rings are clean and not pitted ... they have a tendency to get rough over time and need to be machined for best performance.

Basically this is an excelelnt AC weling machine ... the copper wound rotor adds rotational inertia that improves weld starts over the modern aluminum wound versions.

Good luck!

[Jim Kehler]

Have you done any kind of welding before, if so 7018 s will tend to stick even on DC, IMHO get some 6011's and start welding, it won't look as pretty but its a good place to start.

[Dan C]

I would suggest taking a class in welding depending on your experience.  You didn't provide much information on your experience level, but there are a lot of ways to kill yourself from electric shock, breathing toxic fumes, igniting something combustible or just burning down your house.  A class would go a long way to teaching you how to weld properly and you'll learn faster there than on your own.  Depending on what you are welding someone's life could depend on that weld holding.  The instructor in your class would likely give you a hand in checking out the new machine and making sure it's safe.

 

What sort of condition are the cables or terminals?  I have a Lincoln tombstone, got it for $30 from a guy who said it didn't weld worth a hoot.  Looking at the terminals I was thinking to myself he was lucky he didn't fry himself.  The terminals which had been spliced and extended looked like someone had dragged them over hot steel and burned off the insulation the last 10'.  I cut off the damaged ends out of safety concerns as well as functionality which still left 15', went inside the box cleaned all the contacts and now it welds beautifully!