Chassis leg spot welds 1963 4 door saloon

[wells01]

Hi
I have removed the RH chassis leg and Engine Bay Floor by carefully drilling out all the spot welds. Is it acceptable (To an MOT station) to weld in the new sections by welding and filling into the old spot welds or do I have to weld the seams as well?
Many thanks.

[rayofleamington]

I would drill them out larger before plug welding. (I use ø8mmm and add a few extra for good measure). I didn't seam weld o the last one I did but if it causes an MOT issue, then do both, rather than just seam weld.
The MOT rules state seam weld AND "to manufacturer's specification".
The intent of the rule is that complete panels can be replaced as they were done originally (e.g. by spot welding), and patches must be fully seam welded rather than stitched. Plug welding is going to do the same job as spot welding but doesn't 100% meet the letter of the rules, although it meets the intent.

Seam welding the edge of a box section lip joint will not give the right result (regarding strength / stiffness), although it will pass an MOT.
Plug weldign an area where there are 3 or more sections coming together should be done that the weld bonds all sections - a seam weld is unlikelyu to achieve that.

[wells01]

. Plug welding is going to do the same job as spot welding but doesn't 100% meet the letter of the rules, although it meets the intent. .

Thanks Ray
I think I may go and speak to the MOT tester before I start welding.
Regards

[chickenjohn]

I've had my cars pass several MOT's with plug welded repairs, where the original panels were held on with spot welds. No mention by the testers at all, not even an "advisory!"

If you grind the plug welds down and seam seal and pain then waxoyl the area then it will look original.

[kennatt]

I've had this disscussion with my mot'er before. Patches now need to be fully seam welded.New full panels spot or plug welded.However,what happens when you take a car to mot that had been patched say 10 years ago,and has lasted perfectly well,but was tack welded as was then allowed as long as there was suficient tacks . The Mot'er says in theory he should now fail the car under the present rules Wonder how many out there are like this.Some of the cars would have been done by him since he's been at it for 30years.He says the danger is that it could be vosa test run at him,so when asked what he would do said if he knew the car he would pass it,but would have to seriously think about a car he did'nt know,and decide on pass or advisory or even fail it depending where and how big the patching was, Interesting

[chickenjohn]

I've had this disscussion with my mot'er before. Patches now need to be fully seam welded.New full panels spot or plug welded.However,what happens when you take a car to mot that had been patched say 10 years ago,and has lasted perfectly well,but was tack welded as was then allowed as long as there was suficient tacks .-snip-

This rule was brought in more than 10 years ago! The answer is the car should be failed. Anyway, the lack of work quality suggested by "tack welded patches" suggests that the "repairs" will have rusted through before then anyway!