Welding with Disco

So long as you disconect the battery you ought to be right, that effectively breaks the circuit for all the electrics in your car. I weld on cars and tractors every day for my job and have never had a problem yet only taking off the battery leads. If you wanted to be SUPER sure you could take the wires off the alternator as well but it's not necessary. The thing with Mig welders, as I'm sure you've either found or will find is that the 2 surfaces to be welded together NEED to be really clean from any paint, rust etc.. for them to work well. Good luck, let us know how you get on! I've got to do the floor in my 76 Classic but it's the last thing I feel like doing after work!!!

Richard.

Hi Andy

3mm is probably a bit OTT - you'll have difficulty welding it to the surrounding metal. I'd only use 1mm for footwells. As for disconnecting things, the alternator lead as otherwise you could fry the voltage reg/diode pack.

The bulkhead on your disco is the same as a RR classic, and hence decent replacement panels are available for the side vertical box if necessary. If you're going to do the repair yourself with fabrications, make sure you cut out all the old metal and don't plate over it. You'll often end up having to weld some seams twice, once from the inside and once from the outside to get a nice neat job. Also make sure that you get the metal really clean before welding. Think carefully about where and what you weld too - there are all sorts of parts designed to dismantle, like the bulkhead from the rest of the vehicle and the transmission tunnel etc. If things were originially made from two pieces of metal keep them that way! Sorry to patronise if you know all this already!! Another thing is the water tends to get in from somewhere like the window seal on the windscreen . Once you've welded the footwell up, you might find it starts to fill with water again. It's worth checking the seals at a later date if this is the case.

Have fun, Andy

Yes - somewhere in the 1.2mm range would be ideal. If you disconnect the negative battery terminal you'll be safe, no need to touch anything else and everything is then open circuit. Incidentally a MIG is DC current only and so long as it has decent capacitors inside to remove any AC ripple shouldn't hurt an alternator anyway. I've yet to kill any electrical/electronic bits with a MIG (welding on vehicles at work daily) and all we ever do is disconnect the negative terminal.

On or around Sun, 22 Aug 2004 09:08:12 GMT, "Andrew Renshaw" enlightened us thusly:

!?!?

Assuming you're talking about repairing the floor panel and not the chassis, it's at least 300% over spec, maybe more. ISTR that LR chassis were 14 gauge steel, which is about 2mm. floor panels on such as the disco are probably about 1mm.

3mm on a chassis is over-engineering it, while 3mm on the body is a bit silly, IMHO - if you do any amount of repairs it'll end up weighing about 4 tons.

also, plate that thick is very difficult to deal with for anything but a flat patch. Even 2mm is quite difficult to bend to odd shapes, although it's the right sort of spec for chassis repairs. Most body repairs are gonna be 1mm or 1.5mm at most.

Andy Warner vaguely muttered something like ...

Heheheh, been there got three friggin' t-shirts .. ;)

I once fried one with an AC arc, so I guess I'm just over cautious with the mig!!

On or around Thu, 26 Aug 2004 14:45:26 +0100, "Andy Warner" enlightened us thusly:

never really understood how that happens - if you send current from one part of the chassis to another, adjacent part, I can't see how it gets into the alternator, for example. I've not noticed any problems with migs, maybe the voltage is less?