Welding

ConsumerMan · Senior Member

Welding

Possum3 · Guru

ConsumerMan wrote:
I am about to take my caravan to a local welding guy to have an additional jockey wheel clamp attached. Should the caravan house battery be disconnected before any welding is done? Thanks.

Absolutely! and ensure no appliances plugged into power points/inverters, make sure solar panel isolated - remember 12v systems are usually using your chassis as earth. Ensure the welder earths the chassis to ground near/beside the welding operation.

Hairyone · Veteran Member

If its easy to do it wouldn't hurt, but otherwise I wouldn't worry about it.....as long as he puts his earth close it will be fine and he should know that.

Peter_n_Margaret · Guru

I never disconnect the battery when welding on the OKA, just keep the welder earth close to the work.
Might be different with a modern electronic vehicle, but a caravan is unlikely to be an issue.
Cheers,
Peter

Whenarewethere · Guru

A lot of the welders have a high frequency & higher voltage unit to help get the arc going.

Aus-Kiwi · Guru

Its not the battery ! Its the diodes etc in alternator . Make sure earth is good . Not clamped to rust or paint .

Tony Bev · Guru

Just as there are people, and people, (we are all different)

There are also welders, and welders

Some welders will know to place the earth clamp, very close to the work, and on bare metal

Some welders may put the earth clamp, in their most convenient spot, which may not be making a good earth

I would be disconnecting the battery, just to be on the safe side

Corndoggy · Senior Member

Make sure there are no wires in the place where he is going to weld. Might seem obvious but know some goose that didn't realise and he melted the wires and ended up doing a rewire as well. A real goose, ME. Ha ha ha.

Whenarewethere · Guru

Only the other day on TV some news article there was a scene of someone welding. It looked like current footage.

The welder was using a non photosensitive shield.

I was using a photosensitive shield, a 11x for gas & 13x for arc back in 1988. $800 each back then.

OH&S, it's 2021 use a photosensitive shield, they are cheap these days.

Probably he wasn't using 50+ sun cream either!

peatop · Senior Member

I agree there are welders and then there are welders, we used to use a welding protection clamp on the terminals of batteries that protected them, but to be safe it's always best to disconnect, as for placement of the earth this can be a can of worms electricity finds the least path of resistance, I have seen bearings welded together, nuts to bolts and so on from bad earth placement, 1st rule in welding is to place the earth lead as close as practical to the welding location and clamped to new metal (sanded and clean).

Oh and if you want to watch some funny videos, search youtube for Chinese workers welding, the common practice of using cardboard with a hole cut in it for a mask was one of my favorites lol

ConsumerMan · Senior Member

Thanks for all your advice. I wont risk it and will disconnect the battery before leaving home. As such I guess I should unhitch the caravan from my car whilst the welding is being done. Thanks guys.

peatop · Senior Member

ConsumerMan wrote:
Thanks for all your advice. I wont risk it and will disconnect the battery before leaving home. As such I guess I should unhitch the caravan from my car whilst the welding is being done. Thanks guys.

Yes definitely totally unhook the car.

skins · Senior Member

Yes, I am an ex-Boilermaker / welder, if it was someone else's van I was working on, I would disconnect the battery/s at the very least. If it was my van I was working on I would also disconnect every high end electronic piece of equipment that is earthed if I was doing a lot of welding. But putting on a bracket does not take much weld. Also what peatop says, unhook the vehicle. Dont let the welder convince you otherwise by saying, 'she's right mate'.

jegog · Senior Member

In theory the welder is in parallel with the caravan battery so there is no path for the welder current that passes through the battery. For caravans i would bolt the welder earth to a square of 5mm steel and weld it to the caravan chassis. When finished just break it of off, grind flat and paint.

Aus-Kiwi · Guru

Most connectors are brass or copper .