# Hypothetical emergency welder

• posted
Could a combination of car batteries be combined in series / parallel or
both to be able give enough to weld with in an emergency situation? The
batteries would be 12V with 800CCA. Shoot down this idea quick if you need
to.
• posted
You mean other than how
does it?
Peter
• posted
Educate me on how the ready welder does it. Are these converting 12V to something else? Rather than a welding gun I more of the idea of jumper cables and some rod.
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Hey, I once saw McGyver do it on TV. They can't show that stuff on TV if it isn't real. Right?
Steve
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I'm afraid I can't educate you beyond telling you that it takes somewhere between one and three batteries (six to thirty six volts respectively) at up to 350-ish amps and makes it work. I'm betting Ernie or someone equally knowledgeable will chime in here...
Peter
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I've seen web sites on doing one out of a modified alternator that does 12v stick welding.
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A Google search for ["modified alternator" & welder] - without the brackets - turned up 14 hits and the very first one was
I think you'll find it interesting and you may want to do the search yourself and check out the other 13. :-)
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Ryan Case wrote:
• posted
The Ready Welder is a MIG welder and as such needs (or works best with) a constant voltage power source. Your jumper cable stick welding idea would need a constant current source. Lead acid batteries are constant voltage sources.
HTH, Tom
• posted
| Could a combination of car batteries be combined in series / parallel or | both to be able give enough to weld with in an emergency situation? The | batteries would be 12V with 800CCA. Shoot down this idea quick if you need | to.
Very capable, very doable, and not at all that uncommon. Do a google search for "jumper cable weld batteries" and you'll get gobs of how to pages. One thing I saw done that impressed me was a piece of short smaller wire in the battery circuit that limited current and acted as a fuse. Don't recall the page I saw it, but liked the idea. Between that and a small hobby sized rod the current can be kept down to keep the abuse to a minimum and get a little more life out of then.
• posted
Have read the other posts with much interest.
I once had a car which required welding just by the front quarter light on the 2 front doors. A very good friend and welder suggested I use a couple of D size batteries, looking puzzled he offered more help.
Take the batteries, remove the outer casing until you get the carbon core. this is what you want.
Connect one to +12 V, the other to -volts.
On a small shaft slid one closer to the other until they arc, this will give a very hot source, and very very bright, just like arc welding.
Once this is done you can either braze, or weld, VERY thin sheet in the same manner as GAS welding, the battery gives the heat source, and filler rods are used to get the weld.
Worked fine, but as I say very thin sheet. Ok for a REAL emergency on light stuff, and a great deal of fun.
All the best with your search.
Vaughn
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The resistors in the design are fuses. They get hot and stay ok or over heat to a point and burst. I'd say one would need a 150 Amp fuse or maybe a 100A slow blow fuse...
I have one in that range, but most don't. Mine has lugs to bolt on to, but most house fuses - the old type - for heater circuits - need a holder.
A fuse is simply a conductor that at a certain current flow the metal melts.
Martin
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"Tm" wrote: (clip) Lead acid batteries are constant voltage sources. (clip) ^^^^^^^^^^^ If you have a car with a voltmeter on the dash, watch what happens when you run the starter. For a battery in good shape, the voltage drops to about 8 volts. Of course, that's for VERY high current.
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"lionslair at consolidated dot net"
| > search for "jumper cable weld batteries" and you'll get gobs of how to | > pages. One thing I saw done that impressed me was a piece of short smaller | > wire in the battery circuit that limited current and acted as a fuse. Don't | > recall the page I saw it, but liked the idea. Between that and a small | > hobby sized rod the current can be kept down to keep the abuse to a minimum | > and get a little more life out of then. | > | The resistors in the design are fuses. They get hot and stay ok or over heat to a point and burst. | I'd say one would need a 150 Amp fuse or maybe a 100A slow blow fuse... | | I have one in that range, but most don't. Mine has lugs to bolt on to, but | most house fuses - the old type - for heater circuits - need a holder. | | A fuse is simply a conductor that at a certain current flow the metal melts. | | Martin
Some four wheelers carry a kit of cables and everything they need to weld on the trail, so I suppose an industrial slow blow fuse, a biggun, ought to be a safe item to have, but they aren't cheap, so loading them to the max sounds kinda like throwing money away. A good guess, but close enough, would be a chunk of wire roughly sized to work. One of the first pages you'll hit described using a piece of 8 gauge wire and adjusting the length to control the current.
• posted
Yes and sort of no. Two12 volt batteries will probably give you a lot more current that youwould want to deal with on many/most in field repairs on trucks, 4WDs, ATVs, etc. A 12 and a 6 in series would be a lot more manageable. BTW, *_DO_* isolate them from the vehicle itself before attempting any welding on that vehicle, be cognisent of -'ve ground, etc.
• posted
What you need is some kind of a current limiter. A short on a 12volt battery can be disastrous. The starter motor from a car is designed for very high current use. In series with the battery, it would act as a current limiter resistor.
You could also gut the heater element out of an old cloth dryer, parallel up some of the ni-chrome wire and make a variable resistor out of it by attaching into the coils at different locations.
Oh yes, and use a fuse (circuit breaker), I hear battery acid burns take a long time to heal.
I believe the Ready welder achieves it's controls by paralleling or placing in series, the batteries, to get different current / voltage ratings. There doesn't appear to be any other kind of current control. It seems to have a separate power control for the wire feeder, that , beyond pushing the wire out, has no control over the current.
carl mciver wrote:

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