Replace NEMA 10-50P with 6-50P on ancient welder?

[Member]

Hi,

Somehow my Dad acquired the welder in the attached picture. It has a NEMA 10-50P (two hots and a neutral) on it which 1) I understand is no longer in use and 2) we don't have a receptacle for.

Does the community think I can just replace this plug with a NEMA 6-50P (two hots and a ground)? I see no use for 120 volts in a welder thus no need for the neutral but I'm hoping someone has run into this situation before and can tell me if they think this is okay.

I'm an hobbyist welder with TIG and MIG experience. While this welder actually kind of scares me we're thinking about replacing the plug and trying stick welding for fun. We're kind of going on the theory that it's probably an okay machine and "they don't make 'em like they used to." I'll open it up to check for rodent damage before we do anything.

Also, since I've never stick welded before I have one more question: is this thing electrode hot from the moment I turn on the switch on the front? What do you do with the electrode holder when you're done with your bead, walk to the machine and turn it off?

Thanks.

 

[ThomasH]

Hi,

Somehow my Dad acquired the welder in the attached picture. It has a NEMA 10-50P (two hots and a neutral) on it which 1) I understand is no longer in use and 2) we don't have a receptacle for.

Does the community think I can just replace this plug with a NEMA 6-50P (two hots and a ground)? I see no use for 120 volts in a welder thus no need for the neutral but I'm hoping someone has run into this situation before and can tell me if they think this is okay.

I'm an hobbyist welder with TIG and MIG experience. While this welder actually kind of scares me we're thinking about replacing the plug and trying stick welding for fun. We're kind of going on the theory that it's probably an okay machine and "they don't make 'em like they used to." I'll open it up to check for rodent damage before we do anything.

Also, since I've never stick welded before I have one more question: is this thing electrode hot from the moment I turn on the switch on the front? What do you do with the electrode holder when you're done with your bead, walk to the machine and turn it off?

Thanks.

View attachment 386196

Sure, the only difference in the plug is the non-hot leg shape, they are both rated the same. You are correct in that it used to be fairly common to put in a "stove outlet" and plug the welder in. A welder circuit doesn't necessarily (by code) have to have as large a wire (since the load is dynamic). Therefore, anything that plugs into a 50 amp outlet could plug into the 50 amp outlet with smaller wire, you might plug a large electric heater or oven into the outlet and eventually cause a fire. So they came out with a different plug style for welders and other transient load 50 amp devices.

Yes, the electrode is hot when you flip on the power. You can either hold on to the stinger as you walk to the welder, or just set the stinger on the table with the electrode pointing up and you should be fine.

Your welder is an AC only unit, which means that you should make sure you are using welding electrodes rated for AC use, they will be easier to get an arc going. Since AC units have a full sine wave output, there will be points at which there is zero or close to zero voltage on the stinger. That means that it is more difficult to "strike the arc" and get it going. After that, the welding will be a bit rougher looking than a DC welder, but it will work fine. I used one for years back in the 80s, building boat trailers, and other than being somewhat difficult (until I became more proficient) to get an arc going, it worked fine.

Good luck!

 

[newbury]

If your going to use the rods in the picture they might need some oven time.

 

[Member]

If your going to use the rods in the picture they might need some oven time.

Yeah, they're so old the flux is falling off. We know we need new ones. Thanks.

 

[Reverser]

If your going to use the rods in the picture they might need some oven time.

Member, you would probably be better off just tossing those rod, and get some fresh 6013 or 7014 to practice with.
If you want to use those, knock the flux off of a couple and see if there was rust under the flux. If there is, it would be best to throw them away.



Edit:
Sorry, I noticed you had already said that while I was writing.

 

[Reverser]

Those old AC welders were great work horses and make a good strong weld.
Before plugging it in, of course, I would first check it inside for damage, as you said. And perhaps, blow it out with air and spin the fan blades with your finger to make sure it spins freely. Then put the cover on and plug it in. I'll bet that old welder will work just fine.

Also, you might think about using an old school, twin carbon arc torch, with it. It's the next best thing to having a gas torch. It can braze, heat metal to bend, solder, and get rusted nuts red hot for easy removal without a flame. They are more clumsy than a gas torch, but with practice they can be as handy as a pocket on a shirt.
Yours may have originally came with one, but if it didn't they are easy to make. Or, you might find a used one somewhere.

 

[Member]

Those old AC welders were great work horses and make a good strong weld.
Before plugging it in, of course, I would first check it inside for damage, as you said. And perhaps, blow it out with air and spin the fan blades with your finger to make sure it spins freely. Then put the cover on and plug it in. I'll bet that old welder will work just fine.

Also, you might think about using an old school, twin carbon arc torch, with it. It's the next best thing to having a gas torch. It can braze, heat metal to bend, solder, and get rusted nuts red hot for easy removal without a flame. They are more clumsy than a gas torch, but with practice they can be as handy as a pocket on a shirt.
Yours may have originally came with one, but if it didn't they are easy to make. Or, you might find a used one somewhere.

I just watched a Youtube video demonstrating a twin carbon arc torch. That does look handy. I'm off to eBay!

 

[newbury]

Those old AC welders were great work horses and make a good strong weld.
Before plugging it in, of course, I would first check it inside for damage, as you said. And perhaps, blow it out with air and spin the fan blades with your finger to make sure it spins freely. Then put the cover on and plug it in. I'll bet that old welder will work just fine.

Also, you might think about using an old school, twin carbon arc torch, with it. It's the next best thing to having a gas torch. It can braze, heat metal to bend, solder, and get rusted nuts red hot for easy removal without a flame. They are more clumsy than a gas torch, but with practice they can be as handy as a pocket on a shirt.
Yours may have originally came with one, but if it didn't they are easy to make. Or, you might find a used one somewhere.

Looks interesting!
Make a carbon arc torch for your 220 volt stick welder

 

[Reverser]

One thing to be clear on is that most younger guys and even some older guys, don't know what twin carbon arc torches are. They have them confused with the modern day carbon arc torches used in gouging and cutting. Those use compressed air and are completely different (e.g. Arcair).

Also, before you spend big bucks on eBay for one, you may want to look around garage sales or Craig's List. Or better yet, make one like the link Newbury posted.
Also, look up "twin carbon arc torch" on Google. There are several forums that have discussed them. RankRank1 on this forum, is the authority on the old carbon arc torches and has made several good comments here. There are some that really like them and some that don't like them at all.

I have an oxy/acet torch, and there are a few advantages to using it as opposed to using the carbon arc torch.
A disadvantage to a carbon arc torch is that it's a very hot and bright flame, so you need to wear a helmet and cover your arms, neck, etc, as you would when welding. And, you can't see as well as you can when using gas, since you have to use the welding hood instead of using goggles with the lighter lens. And you can't cut metal like you can with gas. But, to me the pluses outweigh the drawbacks a lot of times.