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Alfa Pages A forum for help with the Alfasud And Alfa 33 |
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Peter (33) Gargano Guest
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Posted: Sat Nov 22, 2003 9:08 pm Post subject: Repairing 33 chassis cracking (au)? |
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Anyone have link(s) to information on how to successfully repair 33 chassis cracking (1985 Ti)?
I have one that someone has very poorly attempted to repair with an electric welder and too small amd too thick mild steel plates.
Subsequently, cracking has extended to the area behind the headlights on one side, and to the front cross-member on the other, but, as bad as it sounds, I think it can be quite successfully repaired with a MIG, and then reinforced so it's better than the original.
What I really want to see is a writeup of the steps involved, and the potential problems.
If I can get enough info to be confident to start, my intention is to write it up, with images, and make it available from either my own web site, or a more appropriate site.
If this has already been done then all the better.
I'm located in Canberra (AU).
I have a MIG, Oxy, (and a pop rivettter
Peter. |
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Peter Gargano Alfa Arna
Joined: 14 Sep 2003 Posts: 2 Location: Canberra, Australia
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Carl Alfa Arna
Joined: 17 Nov 2003 Posts: 13 Location: Melbourne, Australia
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Posted: Mon Nov 24, 2003 5:21 am Post subject: |
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Disclaimer : I am not a welder...
Personally I wouldn't trust it without consulting an engineer.
The existing welds look terrible, with the amount of work to be done, I would be worried about heat stress with additional welding.
It might be better to cut sections out and rebuild than trying to patch what is already there, as the metal that isn't cracked will also be stressed and weakened.
The number of cracks worries me too, the body has obvious taken a pounding, and without going over the entire chassis, you might miss a stress point.
Sorry not much advice, but I'd rather see an alfa go to the scrap heap, than it's driver wrapped around a tree because of a failure.
I think the chassis could be saved, _I_ wouldn't do it, mostly because I don't trust my welding skills , but it would involve heavy cutting, and probably fully welding the affected areas. I think phil storr's got some pages up on the alfaclub site of similar works. The upside if you do it right would be a more rigid body. (rally cars are often fully welded instead of spot, it's heavier but much stronger and stiffer.)
Anyway enough rambling, hope something in there helps you,
-Carl _________________ '86 33 4x4 Monte Carlo Sportswagon |
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Eddie W Alfa 33
Joined: 31 Jul 2003 Posts: 375 Location: new zealand
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Posted: Fri Dec 19, 2003 5:09 am Post subject: |
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Forget the popriveter. It all looks to be feasable with a MIG albeit a bit of a mission . Two questions must be answered first, is there any rot?, why has it failed? Did it fail because of previous crash repair or has it been subject to undue stress. An impartial assessment must be made first. If you are satisfied that it is worthwhile then the following :
The guards off
The cracks cleaned with a wire disc.( that's a twistknot wire gizzo that goes on your disc grinder and will clean rust and paint like you wouldn't believe)
The bracket holding the captive nut for the xmember removed to access the crack properly
Ensure that you are able to align the pieces BEFORE you start any welding.
For long welds(such as down the side of the chassis) do it with a stitching system ie tack then weld 15-20mm,miss the same and weld again etc allow some of the heat to disperse and then weld the missed sections. This will minimise any pulling from shrinkage.
If you have any gaps between edges the same principle applies but with only 6mm long bridges from edge to edge and 6-8 mm misses. Allow all colour to disappear then weld as for long cracks as above.
Use a reasonably short stickout for your vertical welds unless you start blowing holes in which case you will have to lengthen it a little
Use the MIG TWO HANDED with a flip helmet.You will never control a MIG properly with one hand, Believe me I know I've been using one for 30 yrs.
With any cracks across the top or bottom of the rails you should probably plate after you have welded the crack and flush ground it. Any such plates should not have welds straight across the chassis but have angled, curved or diamond shaped ends to avoid a stress riser directly across.
My two typing fingers are getting worn out so I'll sign off.
Good luck
Regards Eddie _________________ A LITTLE FURTHER A LITTLE FASTER |
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