Welding when you're actually inside the vehicle yourself

[JackBz]

Hi - I've used a Mig in the past but at such long intervals that I've never become more than a beginner. Now I've a bigger project going and I'm on a learning curve.
I've only ever welded on a bench or for instance welding in a patch panel from the outside of a vehicle.
But now I've got to climb inside our old VW camper with my Mig and attempt to fill some holes in the same floor that I'm also sitting kneeling on and the Mig is earthed to.
Do I have to take any special precautions so that I don't become part of the circuit? Or might I encounter any other dangers?
For instance, should I be kneeling on a rubber mat to isolate myself from the circuit? Not be wearing steel capped boots? Anything else?
The van is stripped out so there's no upholstery, cables or anything whatever to catch fire.
If these are very stupid questions please forgive me but tell me all the same in caps if necessary.
Thanks!

 

[Ashley Burton]

Your be fine!

Just make sure there is no underseal/fuel lines/tank that will catch fire & probably best to have some ventilation.

 

[merryman]

You have no problems with electrocution, I didn't realise until I mended a Mig, but they work on about 28 volts maximum. You are far more likely to have problems by setting that rubber mat on fire. I tend to have a bucket of water handy when welding car bodies, you think you have removed all flammable items, but sealant stuck on pannels and in joints, always catches fire if it can.

 

[steveo3002]

just worry about fumes and fire , headliners catch fire pretty easy

 

[JackBz]

Thanks for the helpful replies. I can crack on with an easier mind now.

 

[8ob]

Over the years I think I have made every mistake possible when it comes to car bodywork restoration but I have kind of found my way a bit now . If you have been rolling your work around on the bench you need to get a bit more practice in on positional stuff before you start on the vehicle, it really is no place to practice. On floors I would be joggling the edge, hole punching the patch, holding that down with skin pins, removing them one at a time to plug weld through the hole and when done weld around the patch.

Bob

 

[Ashley Burton]

Welding upside down in tight spaces is always great fun!

 

[130]

Your be fine!

Just make sure there is no underseal/fuel lines/tank that will catch fire & probably best to have some ventilation.

This.
Been welding inside cars since I was 11 or 12, now 47

You have no problems with electrocution, I didn't realise until I mended a Mig, but they work on about 28 volts maximum. You are far more likely to have problems by setting that rubber mat on fire. I tend to have a bucket of water handy when welding car bodies, you think you have removed all flammable items, but sealant stuck on pannels and in joints, always catches fire if it can.

Volts is irrelevant it's current that kills

just worry about fumes and fire , headliners catch fire pretty easy

Very true
Was once welding a beetle oblivious to all the horsehair type sound proofing going up behind me

 

[daleyd]

Just don’t do it when your actually driving, otherwise you should be ok

 

[130]

Worked out ok for Herbie

 

[Hood]

Volts is irrelevant it's current that kills

From my understanding that is not strictly true, you need both and what amount that may be varies greatly with conditions. For example a car battery has hundreds of Amps ready to zap you but normally it will not even give you a tingle as the voltage is not high enough. With wet or sweaty hands you have reduced the resistance of your body so you may feel a tingle but again unlikely to kill you. Increase the voltage and things change greatly, so although it is the amount of current flowing through you that actually does the damage it also requires a certain voltage before it can flow enough to do so.

 

[colnerov]

Hi, As it's a VW you may be in there some time. What I will say is watch where you're kneeling, try and make sure you're bearing your weight on an area that is well supported. Either over a box section or supported down to the floor because the weight of your body can distort a flat or unsecured floor and then when you weld patches in or the floor to a side member this can lock in that distortion.

On a more serious note ensure you have a clear escape route from the vehicle or the area if firefighting is not successful. Many years ago a mate and I turned up a follow mechanics workshop and MOT centre to find one of the guys sitting on the floor coughing and spluttering. He had been welding a two door escort sill on up on the ramp. He had been standing on the floor of the workshop with the welder pushed under the ramp out of the way for a clear working area. Someone shouted to him there was some smoke in the car so he leapt up to the ramp, tipped the seat forward and got in the back to deal with it. The action of him getting in made the door close, because the seat was forward he couldn't get to the door handle to open it again. It was a few seconds before anyone else realised, once a rescue was mounted they couldn't reach the door handle because of the height, couldn't let the ramp down because the welder was underneath!!! It was all resolved in the end just before we turned up to join in with all the mickey taking. This could have been serious if he was on his own with no rescuers present.

Colin

 

[Sean]

make sure you have the space to flip your mask or that the solar panel can see the ark, or its cuppa time while you wait for the purple sploges to dissapear

 

[tflnemesis]

Whenever I weld on cars I always have someone else there as a fire spotter. A couple of times they have caught fire and I haven't noticed because of my mask but my spotter has stopped me so we could deal with it.
This was after my first time welding solo inside a car and the underseal on the other side of where I was caught fire and i didn't notice until I got a face full of smoke, luckily I managed to put it out before too much damage but it was very scary...

 

[130]

And watch for light bounce from behind you. A T shirt as my legionaires hat under the mask can help

 

[armalites]

You need to be aware of your surroundings and make sure you are aware of where grinding/welding sparks can end up. It's easy to forget about thing like glass and end up with bits of hot metal bonded to them.

It's important to remember when these thing were built they didn't plan them for future repairs and there will be places that you just cannot get to without cutting away perfectly sound metal first. VW vans are full of bits that rust that you can't get too.

 

[sako243]

Hopefully this will help clarify the situation about voltage and current. About 30mA across your heart is enough to kill you, trouble is you need the voltage to get across. If you imagine a hosepipe you can make the analogy that current is the bore of the pipe and therefore how much water can flow. Voltage is analogous to pressure. The higher the pressure the further the water will shoot out the end. Equally the higher the voltage the further it can jump.

Rough ball park the ionizing voltage of air is about 3 million volts per meter, I,e. If you had a welder at 3MV with the earth clamp attached to the vehicle you could start arcing at 1m.

Another observation is human tissue is obviosuly not as conductive as metal but more so than air. Fatty people would be safer as that's a good insulator and you normally get a good build up around the heart.

 

[Burdekin]

Always good practice to have the earth clamp as close to the weld as possible, especially when working on a car.

 

[130]

Always good practice to have the earth clamp as close to the weld as possible, especially when working on a car.

Even if you have to weld a tag on

 

[steviec_lj]

Ignore them all, you’ll get a right zap, enough to frazzle your little JackBz


Not really, you’ll be fine, as above make sure of your surroundings, what may catch fire, what will smoulder - especially under the vehicle if you’re welding the floor, oh and reflections.

You may wish to think about disconnecting the battery, sometimes it’s not really essential but can cause issues on sensitive electronics. Earth clamp as close to the weld area as possible.