On-Board Welder.

[smritte]

a control circuit that will manage the alternator output rather than the simple approach of just tieing it to 12v and adjusting the rpm?

You can do it but your better off using a 100 amp inverter and carrying a welder with you. I would be curious what alternator the on board companies are using now. The alternator your going to need for your system wont be practical due to the amount of raw power at idle.
That leaves you with one practical solution, batteries.
With batteries you now have two options, your vehicles battery's or a separate supply. My opinion would be a separate supply.
I built a spool gun welder that works on my dual battery set up. The issue though is, I have to disconnect them to make 24 volts. It welds a bit hot but is useable, I loose my radio memories and I have to resync blue tooth. That made me work on a battery pack for the spool gun. Its still being worked on so I don't have a drawing for it yet but you could buy one similar from a company called Karange Welder.

 

[freak4life]

Last weekend on the Fordyce Trail I lost steering to my left front wheel after shearing off two of the three studs holding the steering arm on to the knuckle. Luckily my buddy had a Premier Power Welder under the hood along the skills to use it. It turned out to be a 20 minute fix and we were back on the trail. Had we not had access to a welder, this could have been a catastrophic trip ender not to mention a huge hassle sourcing parts or extracting the jeep off of the trail.

Needles to say, I'm in the market for an onboard welder. After doing a lot of research online, it seems that the Premier Power Welder, LLC is the best option. Any of you have any other suggestions?View attachment 203586View attachment 203589

I’m glad it worked out, but being under a vehicle with only a hi-lift jack and apparently no other stands is a dangerous way to work.

 

[David Lang]

You can do it but your better off using a 100 amp inverter and carrying a welder with you. I would be curious what alternator the on board companies are using now. The alternator your going to need for your system wont be practical due to the amount of raw power at idle.
That leaves you with one practical solution, batteries.
With batteries you now have two options, your vehicles battery's or a separate supply. My opinion would be a separate supply.
I built a spool gun welder that works on my dual battery set up. The issue though is, I have to disconnect them to make 24 volts. It welds a bit hot but is useable, I loose my radio memories and I have to resync blue tooth. That made me work on a battery pack for the spool gun. Its still being worked on so I don't have a drawing for it yet but you could buy one similar from a company called Karange Welder.

if I'm going to be running off an inverter, that's even more reason to have a big alternator. The inverter will suck a lot of power and you have to de-rate the alternator a LOT to account for it's power output at idle. A 350-400A alternator is rated at 200-250A at idle

I'm planning for two LiFePO4 100AH batteries as a 1500-2000w inverter will draw close to 200A and it seems many of these batteries (especially at the low end ~$300 for 100AH) want to be limited to 1c, so I could setup switching to put them in series for welding (if I don't just do a full welder on the inverter).

While I would be very willing to risk a couple of $100 lead-acid batteries for something like an ad-hoc welder setup, at $300 each that starts making me think twice.

David Lang

 

[smritte]

The alternator your planning on running is going to be what's called a 6 phase. The idle current from that would be a bit much. Most of the onboard welders run on 24 volts with the voltage being ~21volt while welding.

The battery pack I'm currently building will fit in a 12X16 pelican case. The size is due to the overall size of the spool gun. Battery wise I have 16 38120 Lifepo4. This is giving me 64ah of current with my welding current being estimated at ~120 amp. It will be tapped for 21v and 24v which will give two power modes for welding as well as being a portable 12v source. You could do something like this pretty cheap. If you just put the batteries in a case, it would take up very little room.

The cheapest overall system to put together is a pair of welding leads and a jumper to series your batteries to 24 volts and just arc weld. I used this method for several years. Its a bit hot but it works well as long as you pay attention. There's a bunch of videos with people doing 36 volts and three battery's. That ends up being way to hot on an 1/8 rod due to the uncontrolled current flow.

 

[surfnturf]

I’m glad it worked out, but being under a vehicle with only a hi-lift jack and apparently no other stands is a dangerous way to work.

It's hard to see in the picture, but the jeep was braced with the wheel wedged tight under the axle with another bottle jack next to it, brake set and wheels chocked. We actually tested the stability extensively and measured for the spring droop before performing the fix. In addition the fully charged fire extinguisher was on hand and ready if needed. We have well over 35 years of experience with trail fixes and have taken every precaution possible every time.