Birty Dastards Jeep Club
Tech Forum => Workshop => Topic started by: 5536paulj on August 13, 2016, 12:27:16 PM
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Found this whilst doing the annual 'trying to make the handbrake work for the MOT' saga
Underneath the chassis from skid plate past rear spring mount, will involve upside down welding. Looks like an original weld has given way. I know there are repair sections available but was going to drill a hole each end and weld it up. Too awkward for a plate really. Any better ideas?
:010:
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I'm just doing a repair today - hairline compared to yours but up by the steering box. I've decided to go for a weld and then plate over half of it approach. I'll then keep obsessing over the area to see if any cracks come back. If they do then it will be operation overkill.
Can you weld it up and put a plate over an area that is easier to make a plate fit? My thinking was more weld length holding the two side of the crack together (if you understand what I'm trying to say :017:)
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I reckon as you say drill and fill.
Maybe a plate drilled so you can secure with a number of rosette welds?
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Will go with drill and fill first which will look more 'factory' for MOT, then see how it holds up at CF, maybe plate later which involves taking off skid plate / exhaust etc.
Thanks
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I've gone beyond anything really looking factory on the jeep but know what you mean.
As it turns out, a £99 Chinese 200A arc welder doesn't do pretty welds like a £450 MIG :icon_redface: penetration was good though and that's always something to chuckle about :003:
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By factory I meant my welding is just as awful as the original so hard to tell it's been repaired!
I'll aim for some good penetration too and finish off with authentic mud....
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angle section and rosette welds should be strong enough if the first fix doesnt work. Stitch weld it to start with then seam weld over the top in the opposit direction
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The most important thing on a weld is to make sure there are no inclusions in the finished job.
So:
1. Flush all mud and rubbish out and allow to dry;
2. Get in with a grinder, Dremmel or weapon of choice to clean the rust off the failed material;
3. Protect bare metal with weld through primer;
4. Jack vehicle to release stress from side rail as far as possible to allow chassis to take factory shape.
5. Ensure that chassis rail is straight, use clamps, jacks, chains anything that won't melt;
(5a). Stop drill ends of crack at this point, but do not weld holes closed, many sectors of industry no longer bother so it's a personal choice really;
6. Grind uniform 'vee' into chassis rail along crack as weld prep, do not go deeper than 1/3rd of the material thickness;
7. Stitch weld crack (20 x 20) starting from the middle then alternating either side allowing to cool between runs;
8. Clean area, remove clamps, drink tea etc;
9. Complete weld run starting from the middle again and allowing to cool often;
10. Clean weld with wire brush and protect (paint outside & waxoil inside)
11. Take photos to refer to if crack reappears, and the reason for not welding the stop drills closed is so you can see if the crack is still going or changes direction after the repair.
Remember: safety first, the author implies no guarantee and good luck.
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Thanks all