E30 Zone

I need to weld a few small parts of the front foot wells.

I'm up for trying anything once, but need to know the basics of the way to do this.

What sort of metal etc do I use to weld on, and how do I prep the surface? Also what is the best type of welder and are they hireable? if so how much?

Thanks in advance!

Right big subject!!
If you have never welded before I strongly suggest you get some one to show you the basics, even if it is the guy who welds on the farm down the road a bit of a 5 min lesson goes a long way. The easiest method is mig welding and it tends to lead to less distortion as less heat/energy is involved so it is the method usually used with cars. I'm sure you can hire them, I have a 130 Amp mig which is adequate for everything on a car unless you are trying to make M30 engine mounts! The key is to remove ALL the rust back to shiny metal. You can not weld rust! Trust me I have tried many a time. You needs mild steel sheet for patches (16 SWG if you go to a steel supplier), go to the scrappy with some snips or just bring back a bonnet and go to it with the grinder, or as I do cut up an old filing cabinet it's just the right thickness. I could tell you how to weld but it could take pages, if you really want to know drop me an email widget@blueyonder.co.uk

It ain't as easy as it looks! I'd really advise against it unless you know someone who's willing to teach you.

My Dad taught me on Oxy/Acetylene but MIG is easier. Be careful!!!

Definitely go for mig welding. You can hire them out although you need to be shown first. There is so much to think about such as strength of the welder and also the wire speed, the gas and the thickness of the metal. I used to weld for a living so I think its easy but then again I had watched for months before I was let loose on it myself! lol

You've got to be aware also that vehicle welding needs continual welds,meaning you can't stop and start in the middle of a run,I used to be a coded welder and my car needed the jacking points done, the mot inspector told me it had to be welded internally and externally, so I just let the garage do it as they knew the procedure,and the obvious safety risks involved.
If you have a go, don't forget to disconnect the battery and alternator as it does't do them any good.
Mine passed the mot, but the welds looked like a row of broken light bulbs,if I say so myself!

If you go the MIG route it is probably best to get flux cored wire if you are going to be welding outside. Otherwise the gas shield can blow away.
Disconnect the battery, remove any carpet or damping and don't forget stuff on the back of the area you are welding, and cover the wind screen and paint work (or interior in you case I suppose) if there is any chance of weld sparks hitting it.

I've heard mixed opinions from MOT stations.

Some say continuous welds, some say they welds need to be ground flush!

I've never had a problem with pulse welding (only do this to avoid distortion) even on cills and around jacking points.

MIG is definately easiest, but it's also fairly easy to kid yourself that the pidgeon poo you laid on the metal is a good sound weld

I think for MOT's it has to be seem welded for patchs and stitch welded for proper repair panels.

I'm guessing there might be slight variations on this as it depends on how strict the MOT tester is where you are ?

shit, didn't realise there was so much to it LOL!

I think i'll pay someone to do it - anyone local fancy earning a few quid!

Widge wrote:I have a 130 Amp mig which is adequate for everything on a car unless you are trying to make M30 engine mounts!

well my m30 hasn't fallen out yet...

every car i've done, i've just bought some thin steel from a metal shop, used tinsnips/angle grinder/jigsaw to cut rough patches out.

you can usually tack-weld the piece to the car in about the right place, then form it to the shape of the car with a mallet.

as Andy says you do need to seam weld all around, but you'd want to anyway really. as far as i know this didn't used to be necessary for mots but the rules have changed.

don't be put off having a go at it! the only thing i'd say is it might be difficult if you're trying to weld to thin/knackered metal around where you need to patch - as turbo brown says you can make what looks like an ok weld which actually has little strength, but this is usually due to not getting enough heat into the metal because you're having problems burning through it if you turn the wick up too much on your welder...

if the metal's relatively thick it's dead easy, i just picked up a friend's set one day and started using it

bosshogg wrote:You've got to be aware also that vehicle welding needs continual welds,meaning you can't stop and start in the middle of a run

i know you need welds without gaps but what do you mean about not stopping in the middle of a run?

does this only apply at certain areas of the vehicle? i've done some pretty shoddy-looking welds for mots and never had a tester bat an eyelid!

You can stop in a run and must on big pannel or very thin metal. but the finished bead must be contiuous.
Toby I just thought seeing the pics in the M30 mount sticky that at 10mm I'd use my arc to weld them, I think my 130amp is a bit crap now after a few years work. But if you use a 130 amp mig to weld those then rock on as theyre damn good welds boy

MIG is the easiest, but a word of warning, buy a decent MIG welder if you are going this route, there is nothing worse than having a wirefeeder that doesn't.. I have a SIP 130 Turbo MIG which was playing silly beggars, so I replaced the hose and the wirefeed mech itself, bought new wire and the sodding thing still jams.

I have actually given up with MIG and moved onto Inverter ARC and Scratch Start TIG welding. Not doing very well with the TIG bit to be honest, seems terribly difficult compared to MIG/ARC welding, I am sure I will suss it though

Mate persever with the TIG once you have the hang of it you will want to TIG everything!!! It just produces beautiful welds and is flexible. You'll soon find yourself welding up cylihder heads and alloy wheels

ahhhhaa

nice to hear your so good with welders widge need a couple of plates on mine soon

No worries mate! when uni's over for the hols we'll sort it out

One thing no ones mentioned yet. Have a couple of buckets of water handy while your welding, and a washing up liquid bottle filled with water is handy too. Stop welding frequently and check for devoping fires, or have someone keeping a lookout for you.

Yup, that is VERY important Brian!

Be very aware about fire, its hard to see when the mask is down and they can start in places that you can't see, the guy I am building my 335i with has already nearly lost 1 car from welding fire. His started inside the sill with all the Waxoyl..

Get yourself 1 AFFF foam extinguisher and 1 CO2 extinguisher, they are about Ԛ£65 each from screwfix.com. Don't be tempted by dry powder, very effective but it's like an explosion in a flour factory when you use it. Foam is great on oil fires and chemical based fires, like burning underseal/subframe bushes:) CO2 is handy as it doesn't leave any mess.
Always keep it next to the exit and ensure you have a clear path to it when welding.

CO2 is a luxury, foam is really the only one needed in a garage. As Brian said, make sure you have a bucket of water handy, also an old rag or sponge is useful, just be careful not to get steam burned when cooling metal.

Right, off to build an engine stand:)