To Weld, or Not To Weld? - fray bentos
Hi, My car has failed its mot because of corrosion of a body panel within 12 inches of a steering component. Garage advises welding (about£150 job)but is there any reason I cant attempt the job myself and just use fibreglass resin,liquid metal etc.
I've removed the rust and left a hole and I fancy having a go at a cost of about £5! Don't care what it looks like as long as it passes.Any help appreciated.
"but is there any reason I can't attempt the job myself and just use fibreglass resin,liquid metal etc." ..... Well Yes. It will fail again and the vehicle will be very dangerous. It must be a structural panel to have been failed. Any MOT tester worth his salt will spot the fibreglass patch or liberal use of underseal or whatever to disguise the repair and prod it to see what it is. I suspect fail reasons are now logged on the MOT computer centrally so even if you take it to another testing station they can see what it failed on last time.
TO WELD OR NOT TO WELD? - fray bentos
Thanks for the reply. The garage tells me the car is not dangerous to drive,the corrosion is on the panel which protects the fuse box and brake cylinder so I don't think its a structual panel.Why would it be dangerous to not use metal for the repair? Thanks.
TO WELD OR NOT TO WELD? - Number_Cruncher
An amazing question!

There are two reasons why excessive corrosion can result in a failure of the MOT test

1) The corrosion leaves sharp edges which may injure pedestrians

2) The corrosion reduces the structural strength of the car, making the vehicle unsafe.

In your case, the structure around the steering is weakened. fibrglass or liquid metal will not supply adequate structural strength, a fully seam welded patch/panel is the only acceptable repair.

If the corrosion had only left a sharp edge, then repairs with filler, tape, fibreglass, etc are OK. But, NOT for structural work.

TO WELD OR NOT TO WELD? - fray bentos
Thanks again! I just don't see how a 2 inch hole in a sheet of metal totally unrelated to anything important is dangerous. This is the 1st time the car has failed in th 9 years I've had it.The car is a Mercedes and I don't think other cars even have this protective shield where the corrosion is.I think I'll do it myself and if it fails,I'm not realy bothered but it would be a shame as the rest of the car is unmarked and it drives beautifully.
TO WELD OR NOT TO WELD? - Statistical outlier
Good job you asked really, would be a shame if you'd not got advice, patched it yourself and then if failed the test again.

Oh hang on...
TO WELD OR NOT TO WELD? - bell boy
rather than using filler why not whack a tin off fray bentos in the whole and cover with underseal ? that way tester will think its metal when he taps the tin and if you leave the "bully beef" in then it will give an authentic thud like a strong seem weld would.
fray bentos corned beef is on special offer in the coop at the moment two for one so job will cost nowt ;)
Do post back OP when car fails again and we can give further advise :)
TO WELD OR NOT TO WELD? - Number_Cruncher
>>so I don't think its a structual panel.

That may be your view; are you a qualified mechanical engineer, with a specialism in automotive structures, with a detailed knowledge of the load paths through your vehicles panels?

Neither is the MOT tester; he's just following some rules, which usually are quite sensible. These rules can err on the side of caution if a panel is genuinely not load bearing.

If you are determined not to weld, why not check with the tester that your proposed repair will be OK before spending your time?

Some good common sense there NumberCruncher!
TO WELD OR NOT TO WELD? - fray bentos
Good idea! I'll check with the tester before. Another alternative is that I have been offered £200 for the car as it is.This will save me £2oo getting it through the mot,£165 tax,£250 insurance,total £800 if I 'scrap it'.The cars probably not worth this so I could be better off doing this.Gonna have to think about it!
It's irelevant whether or not he made a sensible decision - he failed the car, because of the rust, and if you want it to pass you will have to do what he says.
You can appeal if you like, but imho it would be a complete waste of time. I've had a car fail on a brand new exchange steering link. It wasn't worth arguing - I just got another one and the examiner was happy.

If you really want to go down the bodging with a bit of corned beef tin line, you need to have spotted the hole yourself and covered it up months before the MOT. That way it it gets nicely blended in with road dirt, and he isn't allowed to attack the car with a pickaxe to try and find it. But once he's spotted it, the game's up.
TO WELD OR NOT TO WELD? - Number_Cruncher
>>It's irelevant whether or not he made a sensible decision - he failed the car

I almost agree. However, there is an appeals procedure if you feel a bad decision has been made; i.e., a decision which does not fit in with the MOT testing rules.

I've seen this work both ways - in cases where an MOT was issued when the car should have failed, and vica versa. In either case, the MOT station loses, and VOSA become more keen in their monitoring duties for a while!

8< SNIP 8< comments like that aren't welcome in this forum - DD.
TO WELD OR NOT TO WELD? - fray bentos
There comes a time when you have to weigh up the pros and cons of how long to keep a car on the road when it starts to cost more money in real terms than the car is worth. Sadly this may be the time for my 17 year old Merc.So yes,I think it is time to put my hand in my pocket, and buy a new car.
( Like the argument & views expressed and so my comment is made purely to keep the pot boiling :) )

If Fray Bentos is correct in his view that the rusty panel is for cosmetic/protective purposes, and has no structural purpose, could he not remove it completely, tidy up the cut edges & resubmit?

I am reminded of an argument I once had with a tester over the rusty sills on my P4; I considered that with a separate ladder chassis these had no structural purpose apart from providing a step up into the car.

( I lost the argument but it stil rankles, they are L-shaped pressings rather than monocoque sections and there were only a couple of small holes in the step plate )

One mans junk is another mans treasure
TO WELD OR NOT TO WELD? - defender
on steptoes thought ,I had a similar thing with a defender which had worn bushes on the steering damper which would have failed test ,some defenders have dampers fitted and some dont(it is an extra)so cut it off and tester had to pass it
TO WELD OR NOT TO WELD? - sierraman
I have had this argument over my Toyota Hi-ace motor caravan,built on a chassis but the cab appears to be monocoque unless you look closely.As for FB's prob.,if it is just a small hole a back street garage would patch it for a tenner.
I heard a story of someone super glueing a patch on,replicating welding seam with used chewing gum and undersealing the lot-this is not a suggestion BTW.
TO WELD OR NOT TO WELD? - bell boy
Think the days of back street garages doing seam welding repairs for a tenner have long gone.They might as well sell up and build more flats on the land and play at landlords as its much cleaner and healthier.
TO WELD OR NOT TO WELD? - fray bentos
The car passed its mot at another garage as the corrosion is NOT a failure.I am a happy bunny! Thanks for all your comments.Although its for sale in the classified section,if it doesn't sell I will gladly keep it another few more years as it has been the best car I've ever had!
Since it has now been established that the hole is not an MOT failure point, you would be within your rights to patch it up without welding.
I'd cover it up cosmetically to avoid drawing attention next year.

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