Portable mig setup for car restoration?

[Nomad]

Hi folks, I'm looking into the possibility of doing welding in a lockup garage with no power.
Search found a few discussions but they were many years old, just wondering if there's any newer bits of kit that would do what I want?

I have been offered a classic car needing some welding sills etc before it can be mot'd. The work would have to be done in or outside a lockup garage with no nearby power. Being older (late 60s) it will be thick panels compared to modern cars.
My daily transport is modern with lots of electronics so using that to run a power source (additional alternator etc) isn't an option.

My usual portable setup is a 240v clarke pro-90 with co2 and that works fine for me - is there a portable power source that would run that, or something similar that's self-powered?

Cheap and physically small if possible! All suggestions welcome

 

[eddie49]

Any Classic car first registered up to 1. January 1980 is now MoT exempt ( and zero-rated for Car Tax ).
No need to weld it there, just get in and drive home in your rolling restoration project.

 

[stuvy]

Don’t do as Eddie suggest it’s stupid and dangerous.
You will invalidate your insurance in an accident

What work does the car need?

 

[Ashley Burton]

@Nomad sounding like a generator job to me

 

[slim_boy_fat]

@Nomad sounding like a generator job to me

And a fairly hefty one at that?

 

[a111r]

Get a Shipley quote to have it dragged home?
It's a race to the bottom, watch as prices drop to 'very cheap' (imo)...

Plus, cutting and welding cars outside sucks.
If it needs sills, then there may be quite a bit of fabrication on adjoining areas you can't see yet.

 

[gaz1]

Hi folks, I'm looking into the possibility of doing welding in a lockup garage with no power.
Search found a few discussions but they were many years old, just wondering if there's any newer bits of kit that would do what I want?

My daily transport is modern with lots of electronics so using that to run a power source (additional alternator etc) isn't an option.

My usual portable setup is a 240v clarke pro-90 with co2 and that works fine for me - is there a portable power source that would run that, or something similar that's self-powered?

youve partially lost me here

in one comment your stating that youve no power or no near by power

and yet you quote that you use a clarke 90 mig welder

how do you work that when you have no power ?

generator or with an extension cable ?

 

[stuvy]

youve partially lost me here

in one comment your stating that youve no power or no near by power

and yet you quote that you use a clarke 90 mig welder

how do you work that when you have no power ?

generator or with an extension cable ?

the chap says “my normal welder is....” not at this location, I’d guess at council lock up

 

[slim_boy_fat]

and yet you quote that you use a clarke 90 mig welder

Presumably at home? Lock up is the place with no power.

 

[qwakers]

you could buy a welder genset, but multi process or mig machines are 10k plus (really, i just looked it up) a arc genset would set you back 4k.

so the sensible thing is to get a generator that can run your current welder.

my maths says for your welder to run comfortably you want something like this
https://www.justgenerators.co.uk/frame-mounted-site-generators/loncin-lc6500d-as-generator.html
and no, that wont be the cheapest on the market, just the first over 5kva that i could find.

 

[mike 109444]

Come on it's a bout time someone (other than Lorch) built a battery powered mig from say a Clarke 90 maybe....

 

[eddie49]

it's about time someone built a battery powered mig from say a Clarke 90

Rather than a Clarke 90, you'd have to start with an inverter MIG, such as the Static Arc 140 or the Uptime 160. Then disconnect the input bridge rectifier and feed the internal DC bus with 300v from a Li-Ion battery pack salvaged from a crashed EV.

See my post #19 in the cordless Lorch/Fronius thread:
https://www.mig-welding.co.uk/forum/threads/fronius-cordless-arc-dc-tig-unit.96321/

I suggested:
"to weld at 100 Amps with 50v OCV for 1 hour you would need 5 KWh, which is about a sixth of the battery in a Nissan Leaf.
A good Li-Ion battery can hold 200 Wh per Kg, so the battery would weigh a minimum of 25 Kg."

That was Arc, for MIG on thin sheet metal maybe 30 Amps at 20v would be enough, which is only 600 Wh. Plus losses, plus the wirefeed, call it a KW per hour of welding. For an hour of MIG welding, that's only a 5 Kg Li-Ion pack, which is a lot lighter than a 5 KVA genny - and silent too!
Of course, the obligatory angle grinder would also have to be a cordless one ...

 

[waddycall]

Learn to gas weld!

 

[mike 109444]

Ye after making that statement I thought I had better Google "batter powered mig" and it seams there are plenty that have been done mainly with gasless wire (yuck)
OP did say "cheep" though so not sure inverter would be so cheep.

 

[eddie49]

OP did say "cheep" though so not sure inverter would be so cheep.

Could be done:
£150 for the Uptime inverter MIG.
To substitute batteries for the 325v DC bus that the mains provides, you would need 90 3.6v Li-Ion cells in series. If you used 18650's with 2 AH each, that is 650 Wh, so you would have to put two sets in parallel, wired as 90S2P. This total of 180 cells would give you a 1.3KWh battery, providing over an hour's welding time. With the cutting, and then the grinding, that's more than a full day - at least, it is for me!
You might be able to get the cells for £400 ? but then you would have to charge them back at home, and also have to factor in the cost of a Battery Management System. I think this is still comparable to the cost of a 5 KVA genny.

 

[a111r]

What about making an EV interface, Eddie?

 

[eddie49]

Yes, in the Lorch/Fronius thread I linked to above I said:

"In future, the old PTO or "under-hood alternator welder" could easily be integrated into an electric van... imagine a Nissan e-NV200 with a 16A Commando socket and two Dinse sockets... ! "

 

[Lewis_RX8]

I think this is still comparable to the cost of a 5 KVA genny.

Would hope the Genny would come in useful at some other point. Batterys maybe useful aswell but personally i would rather the genny.

 

[willie.macleod]

Just how much welding would be required? Any photos of the rusty bits? The obvious answer is the genny but you would need to ensure it was adequately sized. Depending on the work required I might be going down the same lines as @waddycall and thinking about my oxyacetylene set.

 

[Nomad]

Thanks everyone - all ideas are appreciated !

Some background -
Gas welding I can (used to be able to?) do but I have no gear and getting bottles refilled used to be difficult. Its a good idea but not ideal.
My portable mig is used if I need to go to a mates place to do work for him there (using his electric). The new project will be getting done at a lockup with no power anywhere near.

Building a battery bank wasn't something I'd thought about. I have accommodation near the lockup but they won't want me recharging anything that big so its not practical.

I think the main welding is a couple of patches on the sills + possibly a rear spring hanger repair.
It just needs to be legal at first so patches are OK, I can fit new sills sometime in the future when its black home.

A portable genny to run my existing kit is cheaper than I expected, any advice what I would need? 5kv? Anything to look for or avoid? Quiet would be good. Electric or pull start?

Thanks again