Hi guys, my '93 corsa is in need of welding to the chassis legs and to keep the costs down i was thinking of learning to mig to carry out the work myself, but before i even bother starting to buy stuff i was hoping you guys might be able to advise me on whether a repair is possible and if so how you would do it? Ive created a photo album called 'corsa rust' see what you think. http://www.mig-welding.co.uk/forum/album.php?albumid=1037 i was hoping to cut the rust out and replace with new metal rather than patch over? im posting this from my phone so hope you can see the pics. thanks in a advance, Kyle
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the snooper
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repairing box section is very straight forward and the rust you show is only a small amount so get yourself a welder and have a go
any repair is possible it just depends on how much time you want to spend doing it
any repair is possible it just depends on how much time you want to spend doing it
brightspark
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the general rule of thumb is if u see 1 :inch theres 6inch to weld
the snooper
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yes i agree it does tend to spread i usually find it all with a nice hammer then cut it out
then cut it outirondarren
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A fair amount of work to there, my personal opinion is if you are going to keep the car, then cut it all out, back as far as you can until you hit clean metal. In cutting away you will have to be careful not to weaken it to much and cause distortion. Prop it brace it etc as much as you can. Try to do the repair one section at a time only cut away what you are working on. best of luck
pedrobedro
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I did the same part on my daughter's Corsa B last year, there are a few layers of metal there. Yours looks like it's already been done once on the bottom part and trapped water has rotted it through again. It hardly supports anything and will be safe to cut out without worrying about distortion.
pedrobedro
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The part of the inner wing carries on down into the rail so it's like a double skin and the outrigger where everybody puts the jack overlaps onto it as well so there's quite a bit to grind down. I use a blowlamp to get the underseal soft to scrape the majority off. Watch out for the pipes and get someone to fire watch pulling the carpets back inside.
pedrobedro
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I was not too worried about the cosmetics and I just hammered the remaining metal to get rid of the rust then I made a piece of channel from 16g (about1.5mm) and knocked it over the top then welded round it, she was swapping the car and wanted a year's test on it to sell it. I had to get the head skimmed and do the gasket on it as well as it was a bit warped.
I had to do exactly the same repair to my wife's corsa. As was said previously there's more than one layer there. I used a grinder to grind down to the inner layer which was thin but not holed.
The hardest part was access, getting a grinder in with a thin cutting disc was hard close to the body. I ended up using a sharp chisel in places. The pipes can be unclipped and pulled to the side, I wrapped them in wet rags.
The underseal was very rubbery and came off best with a sharp blade (strangley there was no paint under the underseal just bright metal in places). I also folded a piece of U channel from sheet tacked one end on the bottom near the outrigger and then hammered and tacked the rest into place.
That rust looks more serious and looks like it would be worth cutting quite close to the underside. I would do it in three sections side - bottom - side to stop anything moving. If you do cut it away completely I would put some diamond plates overlapping the butt welded side plates as that area looks to be in tension.
I would also put a big drainage hole in and fill it with waxoil or dinitrol.
The thing I hated most was the lack of access even with one side up on the axle stands welding the inside of the chassis rail was a real pain.
The hardest part was access, getting a grinder in with a thin cutting disc was hard close to the body. I ended up using a sharp chisel in places. The pipes can be unclipped and pulled to the side, I wrapped them in wet rags.
The underseal was very rubbery and came off best with a sharp blade (strangley there was no paint under the underseal just bright metal in places). I also folded a piece of U channel from sheet tacked one end on the bottom near the outrigger and then hammered and tacked the rest into place.
That rust looks more serious and looks like it would be worth cutting quite close to the underside. I would do it in three sections side - bottom - side to stop anything moving. If you do cut it away completely I would put some diamond plates overlapping the butt welded side plates as that area looks to be in tension.
I would also put a big drainage hole in and fill it with waxoil or dinitrol.
The thing I hated most was the lack of access even with one side up on the axle stands welding the inside of the chassis rail was a real pain.
the snooper
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if the section is rottern all round then there is no point in doing it in three peices (to stop distortion) as there will be no strength in it anyway so if it was going to distort it would have done it already.
thanks for the further replies, i was thinking of adding a drain hole (or 2) as thats obviously where the problem lies, a guy i know whos done a couple of patches on my sill for mot has had a look and reckons cutting it out and welding new pieces in would leave it too weak, and if he was to do it he would prefer to weld whole new chassis front sections in, too costly to bother with. what do you think to cut out and new patches too weakening?
How does he think the new chassis sections are held together?
Cutting out and welding in a patch with a good seam weld is deemed acceptable for MOT because it's as strong as the original part.
Sounds likely he thinks the job he would do wouldn't be strong, or he wouldn't take the time and care to make it strong. The job you should do will be better than that. Remember - plug-welds are fine on a join that was originally spot-welded. Seam-welding is required where there was no join originally.
Of course it's easier for him to supply and fit new parts but it doesn't help you much and it's one reason to learn to weld - your time may be a lot cheaper than his.
hes thinking of my safety mainly and perhaps just thinks lots of patches, well 3 really, means lots more welds and more possible places to fracture, whereas a new section would be less joins. im no structural engineer, lol, but have heard that good welds can be as strong as if not stronger than the steel itself. btw hes not thinking of the money because he knows i wouldnt pay more than its worth. i also think he wouldnt want it on his conscience if anything happened.
also refering to hairyones post about putting diamond plates over the butt welds, how about if i was to put a piece inside the rail behind the hole and dril through the original steel to plug weld it before adding the outer layer? would this add the tension it may need?
