Lightweight welding with a car battery?

[kevanf1]

Has anybody ever tried lightweight arc welding using a car battery (or batteries in series)? by light weight I mean thin sheet stuff. I want to use some rods for both aluminium and stainless steel (different projects) but I understand they can only be used DC. I only have an AC welder and cannot afford a DC welder

Any advice greatly appreciated.

Take care.

Kevan

 

[madkayaker]

stick welding ali is a hard process anyway and is viewed as an emergency last resort by many. the rods will probability need a large open circuit voltage so you would need lots of battery and i wouldn't recommend sparks around battery's.

so in my opinion your barking up the wrong tree but will prepare to be corrected if it proves to be viable (and i have a few car battery's laying around)

 

[rtbcomp]

Rawlplug made a device called "The Welders Mate" for doing just that, though I don't know whether it would have been suitable for aluminium or stainless.



You may have trouble welding thin sheet with arc anyway, a search of the Arc welding forum might throw something up.

 

[Omniata]

Don't bother with arc for Ali on thin stuff, you'll just blow holes and make a poor weld...

Ali arc is really for heavier material such as castings, and at best to fill craters and holes...

DC arc welding of thin stuff is achievable, I've managed 2mm, but it's a bit touch and go and takes practice
It can be done on thinner and I think the best way with DC would be electrode positive, putting less heat into the material and more into the rod so you could drop the current... (I think that's the right way round )

Alternatively drop the current as low as you can to start an arc and keep it going with AC and you'll get somewhere in between DCEN (electrode negative) and DCEP (electrode positive)..

 

[brightspark]

Rawlplug made a device called "The Welders Mate" for doing just that, though I don't know whether it would have been suitable for aluminium or stainless.

they were a joke when they were brought out . my mate bought one and pinched the next door neighbours battery to try welding a side car on a motor bike funny if nowt else

 

[kevanf1]

Fair enough, this looks like a none starter. I've done DC welding of sheet metal amny, many years ago when I first learned how to weld at night school. That was using a generator and it was an absolute joy to use. I'm stuck with a big old oil cooled AC welder and trying to weld sheet steel is akin to herding cats

The aluminium stuff is only small (inch long) pieces on the bodywork of my Land rover so I'll use some of those Durafix style soldering rods instead.

The stainless could be more tricky. I wanted to make a new bespoke fuel tank, again for the Landy. I can do it in mild steel but I wanted the longevity of stainless regarding corrosion etc. It'll just have to be well etch primed and painted

 

[mrcheese]

This was done as an emergency repair.

http://www.youtube.com/watch?v=Uovu-BdvTO0

Was not me by the way, but a friend of mine. The repair held.

You can also buy these, but I have not used one.

http://www.readywelder.com/

 

[kevanf1]

This was done as an emergency repair.

http://www.youtube.com/watch?v=Uovu-BdvTO0

Was not me by the way, but a friend of mine. The repair held.

You can also buy these, but I have not used one.

http://www.readywelder.com/

Biggest problem with those MiG units is the price. A very rough currency translation puts the cheapest at around £300+

I could, get a spool of aluminium wire and a bottle of argon for a lot less than that and use my mig welder to do it. The only reason I haven't done this is because I'd have pretty much a full roll of wire left. I may have to go down this route though, I'll see...

 

[shenion]

Why would how much wire you have left matter?

 

[kevanf1]

Why would how much wire you have left matter?

Because, due to health reasons money is tight. For this reason I don't want to buy a complete roll of aluminium wire only to use probably 5 or 6 metres of it at the most. The rest of the roll would then be left sitting on the shelf in my workshop possibly for the rest of my life.

 

[hotrodder]

0.5kg spool of ally MIG wire is under a tenner, a 2kg spool will still be cheaper than 1kg of those monkey metal aluminium rods although obviously there's the cost of argon to consider. If you've never welded ally before then barely using any of a roll of wire is unlikely to be an issue, reckon on quite a bit of practice and frustration.