Auto Welding precautions

[chrismorg]

Hi could I ask some advice please?
I am planning to cut out and patch some areas of my 1975 midget such as small areas of floors, arches etc. I have heard of problems blowing certain electrical components if not disconnected but this was a friends porsche with complicated circuitry.

How far do I need to go regarding disconnecting / removing electrical components before I begin Mig welding on my Midget?
Should I take any particular precautions regarding the fuel tank? The rust appears not to be closer than 50cms from fueltank.

thanks, great forum by the way - have been browsing for a while
Chris, Newport

 

[Wozzaaah]

Hi Chris, welcome to the forum .
Your post is a perfect candidate for this , I was always told to disconnect the battery before welding to minimise the risk of blowing sensitive electronics but others have been instructed to leave it connected. However.....your car is a midget so there are no sensitive electronics, the only thing you may damage is the alternator but pulling the plug out of the back eliminates the risk of damage. I did a lot of welding on a midget a few years back, just disconnected the battery and it was fine.

 

[Paul.]

Hi,
Always put the welding return (earth) as close as possible to the weld area, never be tempted to clip onto a wheel stud or nut, the current will pass through the bearings, and never onto the engine, as the current may pass through the engine earthing strap or worse stil the wiring loom.

 

[snowcat]

I wack a spike protector on some gear, especialy as GPS is becomeing common place on earth movers, that said, in 15 years, I have never or heard of anyone spikeing a machine through welding...the above two mention good practice tho.

 

[gavuk]

i bought a draper spike protector cost less than a £10,which i still use ,at that price,i leave the battery connected and always clean the earthing point,haven't fried anything yet ,fingers crossed .used to disconnect battery before i bought it though

 

[fingers99]

I'd be inclined to remove the battery (put it on trickle somewhere else!) and unplug the alternator and take the fuel tank out. A fire extinguisher (near the garage door!) and a squirty bottle full of water should be all the other stuff you need.

 

[chrismorg]

Thanks all - very helpful indeed. I just need some tuition in the basics now, seems college instructors dont want to know about private tuition. I have approached some local guys but they all say I have to wait until September for the courses. I have read a few books but would benefit from feedback re technique and the midget can't wait until after the summer!
Does anyone know of any ex welding instructors in South Wales wishing to earn a few bob?
Chris

 

[snowcat]

I'd be inclined to remove the battery (put it on trickle somewhere else!) and unplug the alternator and take the fuel tank out. A fire extinguisher (near the garage door!) and a squirty bottle full of water should be all the other stuff you need.

Blimmy fingers, you missed out the Hot works directive, and the banksman, on fire patrol

 

[Drains]

Fingers, you're a joker mate. Take the fuel tank out, I like that.

On a midget, at MOST disconnect the earth lead, although personally I wouldn't even bother with that.

Not sure i'd bother with the fire extinguisher either. Does rust burn?

 

[Wozzaaah]

I've never removed a fuel tank to weld any car unless the repair was inaccessible with it in place, as long as the fuel lines aren't perished and everything's in good order then the risk of fire is miniscule.

Having said that, one of the lads I used to work with did remove a tank and drained the petrol into a plastic bucket which he placed to one side and proceeded to weld the car......... with hot spatter falling into the bucket!
The result was a flaming, melting bucket of petrol which could have been catastrophic if my boss hadn't spotted it burning and grabbed an extinguisher!

 

[malcolm]

I quite often take fuel tanks out while I'm welding. Depends on the job and whether the tank looks a bit leaky. Wouldn't normally when welding 1/2 m away though.

For learning welding Chris - the tutorial might get you going - practice on scrap and there's nothing to lose.

 

[chrismorg]

I appreciate the info!
Thanks all.

 

[fingers99]

Blimmy fingers, you missed out the Hot works directive, and the banksman, on fire patrol

Well, I'll admit that it's not always how I work, but..............

Remove the battery, not so much because it's a hazard, or will get harmed, but so that it can be trickled. Takes minutes, may save a few quid if the battery dies through non use. Chances are, there will be rust in the battery tray, anyway!

Fire extinguisher, well, we all ought to have them. Near the door cause you don't want to be running through the flames to get to it.

Normally I find a squirty bottle does the job.

The fuel tank might as well come out -- we're talking restoration here, I think, not sticking a sill on somethiong to get through an MOT. There's always the chance/likelyhood that there will be rust in that area anyway.

50cm (that's about from my elbow to the tip of my fingers) is miles away for TIG, fairly close for MIG, and too damn close for gas or arc, in my view.

Rust doesn't burn, but the underseal holding it together does!

I used to know someone who was acting as banksman for a welder. He dozed off, and the whole interior of the car got trashed!

 

[gavuk]

worth hanging around after welding for at least !/2 hour on firewatch ,knew a fella who destroyed a customers car and his beloved classic when he left too quick after welding,they think carpets caught light after he had left from splatter ,mot work not resto ,

 

[snowcat]

Well, I'll admit that it's not always how I work, but..............

Remove the battery, not so much because it's a hazard, or will get harmed, but so that it can be trickled. Takes minutes, may save a few quid if the battery dies through non use. Chances are, there will be rust in the battery tray, anyway!

Fire extinguisher, well, we all ought to have them. Near the door cause you don't want to be running through the flames to get to it.

Normally I find a squirty bottle does the job.

The fuel tank might as well come out -- we're talking restoration here, I think, not sticking a sill on somethiong to get through an MOT. There's always the chance/likelyhood that there will be rust in that area anyway.

50cm (that's about from my elbow to the tip of my fingers) is miles away for TIG, fairly close for MIG, and too damn close for gas or arc, in my view.

Rust doesn't burn, but the underseal holding it together does!

I used to know someone who was acting as banksman for a welder. He dozed off, and the whole interior of the car got trashed!

Can quite see what your saying just tickled me, Cant see it working for myself, "Ok lads, hardface that blade you say, how many litres of cherry you got in the tank, just the 400, right were pop that off, take the baterys out, unplug a few harness, oh and il just need a banksman incase these 20acres of mud catch"

 

[zzr1200]

50cm (that's about from my elbow to the tip of my fingers) is miles away for TIG, fairly close for MIG, and too damn close for gas or arc, in my view.

Arc: I used to weld Land Rover Chassis sections, until I purchased a mig. Car chassis/panels your haven'ing a laugh, I've cut a few up using arc thou.
Gas: The old tried and tested method of sticking rusty stuff together.
Mig: I work on 100mm approx provided the tank is sound and no burny type stuff around the weld.
Tig: Never used tig to date on car body work.