4 replies to this topic

[mk=john]

Hi, I have a fully restored 998 Cooper, and this is negative earth.
I am arranging for either myself or someone to do some plug welds to rejoin the grill panel with the bonnet lock panel, as some of the spotwelds have broken free.

I have never done any welding before, so have thes questions:

1)If I attatch the welder earth strap (a gas MIG welder) to the car body, do I have to de-earth the battery, engine etc, and what other precautions should I take electrically.

2) Am I likely to cause paint around the body to bubblr or get hot beacuse of the current passing through the body, and if so, what precautons can take?

3) Generally, what ampage should I set the welder to
4) What size wire should I use, and is there any flux that need to be romoved prior to painting?

Thanks, I look fwd to your help, and any other advice you can give
Cheers

John

Sorry, it is a positive earth car..!!!!

[Jimmyarm]

I am no welder but have been reading up on some stuff so;

Disconnect the battery completely to avoid any electrical issues.

Your going to have to repaint around the weld areas anyway as you need to grind the existing paint off to get a decent weld, other than that you'll need some welding blankets to protect the areas around where you are welding.

Have a look on www.mig-welding.co.uk that sites really useful and has given me enough confidence to have a crack at it myself (once my welder comes through !)

From what peeps say, its a case of practise practice practice ! Before I go anywhere near my car I am going to knock up a freestanding shelving unit from angled steel and sheet steel as a test

[campfreddy2]

hi
REALLY important- Disconnect the alternator or you will fry it!
When my mate taught me to weld, he said go round to an engineering firm and ask them for some scraps from the waste skip.
I was then told to write my name in weld on the waste sheet - when I got it so it was legible and italic and made a crackling noise it would be ok!
seems to have worked as have done my sons old and my current even older mini's and they flew through the MOT.
if you google mig welding - there are some really good pages.
good luck
col

[minivanman]

frost do some stuff called cold front - its supposed to take the heat out of the welding area - prevents buckling and blistering the panel. I've not tried it myself but it may be worth it if you are worried

[Bam]

Like what is sead above disconect and remove the altenator and battery and if welding near fule lines or the tank then be very carefull.

pratice on some scrap metal as it is almost impossable to say what setting to have the welder on as they are all diffrent.

play with diffrent settings untill you get a good run, then try some simple joints.

once you are happy with the standard of your pratice peices then try a pannle.

I weld alot so if you have any questions then please PM me and ill try and help.


Thanks.


Chris.