Why do cars rust the way they do? It's not unheard of for some relatively modern cars to be failing the MOT due to rust. I've just realised that farm machinery spends lots of time outdoors (sometimes all of it's time), often has chipped paint, is covered with mud and yet rarely rusts much beyond the surface.
You're buying the wrong brand of car, then.
Look for something galvanised, like, for instance, a Fiat / Alfa ;-)
Seriously, though, Vauxhall and Ford were seriously behind the times when it came to rust prevention - probably because they expected the car to expire before it rusted away..... whereas the French, Italians and Germans have been pretty damned good for the last 15 years.
Farm machinery is typically made of 6-20mm thick steel, with the only parts made of thin sheet being removable covers. Car bodies are made of
1.2-2.0mm steel. Go figure.The message from "Doki" contains these words:
Rust usually starts in seams - most commonly over the rear wheel-arches where there's a narrow angle between the inner arch and the outer. I reckon it's mostly condensation in the void inside the rear wing that runs down and settles in the crack.
Probably the only way round it is to design it so that there isn't a trap there - but that ain't easy.
Fundamentally it's down to diminishing returns - car firms ain't really bothered what happens to their cars after a few years as it doesn't really affect how much they can charge for 'em when new - so there's little incentive to fix it beyond six or seven years.
Reminisces and sighs
"How I loved my Montego"
The message from "John B" contains these words:
S'not just Monties that go there - Maestros do it too, you know!
And Metros, Astras, Sierras - in fact, just about anything that rusts does it there.
More to it than that, though, otherwise cars would rust through everywhere. But you rarely see one with holes in the roof.
It's commonly where two bits of pressing are welded together and moisture gets trapped. The moisture acts as an electrolyte and the two pieces of steel as anode and cathode.
Even my SD1. Although it's only just started after 20 years. Montegos managed it in 20 months.
It's a shame, really, as both it and the Maestro were basically good cars let down by appalling build standards.
In news: snipped-for-privacy@davenoise.co.uk, Dave Plowman (News) decided to enlighten our sheltered souls with a rant as follows
IIRC all Montegos and Maestros rotted at the seams because although the body was rustproofed in some newfangled way, it was done before the shell was actually assembled. When it was welded together the welding process destroyed the rustproofing. I worked for a short while in an Austin Rover bodyshop as a YTS and most of the painters spent most of their days fixing rusty joins as part of the PDI.
cant agree, or at least on my car, rust buckets usually but my old man had a measto something, all leccy bits, he had it for 15 years and was fine, seen some rust buckets much younger.
Only cars i had that have ben reliable are Toyotas or a FSO
I can beat that! I had a new Monstroustego diesel as a lease car in 1992. 18 months later with 55,000 miles on the clock it had rust in the seams on the A pillars, and bubbling starting on the rear wheel arches. I did spend a lot of time driving on muddy Mid Wales roads, but that's still good going!
It had also had a new turbo and short engine in this time. Glad I hadn't spent my own cash on it!
My 87 325i is rusting on the roof :-( I'll miss it when it's gone.
But otherwise a fair point.
But farmers go out, combine a field or mow hay, fill the bearings with sap and organic stuff. Then they park it for 11 months. After which they spend a week replacing lots of bearings before they can use it again. Can't be arsed and/or work too hard 24/7 to spend 1 hour cleaning it. After the third time they have taken a welding torch and big hammer to the bearing housings they need a new one.
Farmer back of me had a wheel bearing collapse on his trailer a few years back. The trailer was a 38ton artic lorry trailer with wheel bearings that run 100,000's of miles and he F***d it just shuffling his hay bales about the village. Because he had never maintained it for 5min a month with a shot of grease he wound up having to shift the bales one at time on a tractor with a spike on the fork lift. He didn't seem to do much else for a week solid from 5am until 11pm until he got a new trailer.
-- Peter Hill Spamtrap reply domain as per NNTP-Posting-Host in header Can of worms - what every fisherman wants. Can of worms - what every PC owner gets!
Doesn't the quality of steel used also make a difference? I own an old H-reg Astra, which lives outside in all winds and weathers, yet it has hardly any rust at all, whereas my next-door neighbour, who owns a P-reg Ford Escort, has just had to have lots of expensive underbody welding work done, just to get it through its MoT.
That's the paint job not the steel
A while back I read an article on a bloke who was running a firm hiring out muck spreaders. He eventually ended up building his own muck spreaders because the commercial ones were designed to do 2 or 3 days of work a year and just couldn't stand any serious use. God knows what that bloke did the artic trailer though.
Yep. But there are some truly ancient tractors knocking around which you'd really expect to have rotted through on the mudguards / wheel arches which aren't astoundingly thick.
It's that special attractive force between iron oxide and the blue oval badge at fault there ;-)
Oxygen and water are essential for rusting to occur.
However the process can be accelerated by cold working the steel.
That is why the bodies rust at the cold pressed areas.
This could be simply overcome by heat treat>Doki wrote:
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