Is welding seat rails advisable or lethal?
Discussion
My car is in the dealers having a seat issue sorted.
They've just phoned to say that one of the bolts securing the seat rail has threaded and that they might need to weld the rail in place instead.
A quick google suggests this could be a very bad idea, namely for saftey. Is this correct?
It's a franchise dealer for a big German Brand, so not a back street garage.
Any experience and advice most welcome.
They've just phoned to say that one of the bolts securing the seat rail has threaded and that they might need to weld the rail in place instead.
A quick google suggests this could be a very bad idea, namely for saftey. Is this correct?
It's a franchise dealer for a big German Brand, so not a back street garage.
Any experience and advice most welcome.
One assumes they have already considered drilling out the hole, re-tapping and securing with a slightly larger bolt, but had to discount that?
I'd personally have no qualms from a safety perspective if the welding was to a good standard and there was plenty of it, provided that the other three mounting bolts are all secure?
I'd personally have no qualms from a safety perspective if the welding was to a good standard and there was plenty of it, provided that the other three mounting bolts are all secure?
legless said:
This needs repairing properly.
Agreed, but how? Is drillling out for a helicoil any stronger? Would it need retapping to oversize - potentially making the available, and presumably stengthened, metal in the mounting area smaller? Sounds like a PITA any which way you look at it. SteveStrange said:
Agreed, but how? Is drillling out for a helicoil any stronger? Would it need retapping to oversize - potentially making the available, and presumably stengthened, metal in the mounting area smaller? Sounds like a PITA any which way you look at it.
Exactly this.I've read that welding the floor can weaken the metal
And as someone pointed out above - a weld could behave very differently in a crash, which is my biggest concern.
A *good* weld can be stronger than the original metal, and large parts of the vehicle (including the seat supports) are likely multiple pieces welded together. Therefore it's logical to assume that welding seat parts is almost certainly safe.
However. I've met a lot of welders who are better with paint and a grinder than they are with a welder...
"A grinder and paint make you the welder you ain't" as they say.
Short answer: Depends on whether it's being welded by someone good.
However. I've met a lot of welders who are better with paint and a grinder than they are with a welder...
"A grinder and paint make you the welder you ain't" as they say.
Short answer: Depends on whether it's being welded by someone good.
SteveStrange said:
legless said:
This needs repairing properly.
Agreed, but how? Is drillling out for a helicoil any stronger? Would it need retapping to oversize - potentially making the available, and presumably stengthened, metal in the mounting area smaller? Sounds like a PITA any which way you look at it. Unless the garage is going to provide an engineer's report (NB not a technician report saying "I yanked on it, it's fine" - I mean an actual engineer, doing maths) then tell them to FRO.
If it's a warranty/recall job I might be tempted to insist they get an engineering shop to do the helicoil so it's not just been whizzed in to an oval hole...
RicksAlfas said:
OP. Are you sure they said welding?
Welding it would mean removing all the soundproofing, carpet, paint, corrosion protection from that area.
YupWelding it would mean removing all the soundproofing, carpet, paint, corrosion protection from that area.
I'm not sure the nice lady on Service had much of an idea, it seemed to be a suggestion from the Technician that she was simply passing on - she said she would speak to her service manager and let me know.
I've already expressed my 'utmost concern' as this seems to provoke a very mixed reaction and saftey is a no compromise area for me.
I'm less than 6 months into ownership so might look into rejecting it if this is the only course of action.
I had floor cracking on an early 106 around one of the drivers seat rail mounts. My uncle (a coded welder who worked on Armco during his day job) repaired it by levelling, then welding up the cracks, then making up a reinforcing plate which he welded seamlessly to the floor, and drilled to line up with the existing bolt hole, so the original mounting hardware could be used. Once it was seam sealed and painted, it looked like the factory put it there.
I can stick bits of metal together with a mig welder, but the potential safety implications of stuff like this mean it really needs to be done by someone who knows what they are doing.
I can stick bits of metal together with a mig welder, but the potential safety implications of stuff like this mean it really needs to be done by someone who knows what they are doing.
Get some paperwork from them to show this is the only course available, let them crack on. A lot of mounting points for seats are very thin and/or surprisingly weak. The real strength is put into the seatbelt mounts.
Even a tiny amount of decently penetrating weld will be more than capable of holding a seat in place, even if the others are magically removed.
Even a tiny amount of decently penetrating weld will be more than capable of holding a seat in place, even if the others are magically removed.
Krikkit said:
Even a tiny amount of decently penetrating weld will be more than capable of holding a seat in place, even if the others are magically removed.
I remember an old Austin Metro I had, the only thing stopping the drivers seat falling through the floor was a hairbrush handle wedged through a hole in the seat runner. Passed an MOT like that too. Aah, the '90's 
legless said:
The seat mounting fixtures are a key part of the overall restraint system and come under incredible levels of force in an impact. There's no way of knowing whether a weld would behave the same as the bolt that was used as part of the type approval.
This is the correct answer for the same reason wire splicing is now prohibited for lifting gear at sea.Anyone competent can torque a type approved fitting to the correct number, and get the same result each time.
It’s harder to gauge the finished job if ‘skill’ is added as a variable factor.
I would pursue this through the garage higherachy to ensure the correct work is carried out (says the man who repaired a pulled out strut top mount with a riv-nut & drove on it like that for a year!).
Stick Legs said:
This is the correct answer for the same reason wire splicing is now prohibited for lifting gear at sea.
Anyone competent can torque a type approved fitting to the correct number, and get the same result each time.
It’s harder to gauge the finished job if ‘skill’ is added as a variable factor.
I would pursue this through the garage higherachy to ensure the correct work is carried out (says the man who repaired a pulled out strut top mount with a riv-nut & drove on it like that for a year!).
They're now saying it was a miscommunication and they need an external company to come in and 'clean up' the thread.Anyone competent can torque a type approved fitting to the correct number, and get the same result each time.
It’s harder to gauge the finished job if ‘skill’ is added as a variable factor.
I would pursue this through the garage higherachy to ensure the correct work is carried out (says the man who repaired a pulled out strut top mount with a riv-nut & drove on it like that for a year!).
He's removed welding from the conversation. He went on to say there is no safety concern.
We'll see. Wonder what the hell 'cleaning up the thread' means?!?
Stick Legs said:
I’d wager it was cross threaded by some oaf inserting bolt into tool, then trying to start the bolt with the power tool, rather than starting the bolt by hand then whizzing it up.
Yup. And all part of the £145 an hour service - or whatever it is they fookin' charge these days.Is cleaning up the thread a 'thing' ?
What was the original issue? Was the seat loose to begin with or have they taken it out for another reason and buggered the thread in the process?
Is it the driver's seat? If not I'd be inclined to decline any further assistance and drive it to a proper garage. If they caused the issue maybe suggest they pay to have it transported to this better garage.
Is it the driver's seat? If not I'd be inclined to decline any further assistance and drive it to a proper garage. If they caused the issue maybe suggest they pay to have it transported to this better garage.
Edited by Automaton on Tuesday 13th September 18:39
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