Why do some cars have a propensity to rust?

Why do some cars have a propensity to rust?

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Discussion

white_goodman

Original Poster:

4,111 posts

199 months

Tuesday 28th June 2011
quotequote all
I have been looking for a tidy mk1 MR2 recently but they seem to be hard to come by as many of them have rusted out. Why is it that a car made by a manufacturer for a reputation for mechanical durability and reliability can have such terminal rust problems? I believe the same is true of the original Honda CRX and early MX5s. I know that the newest examples are getting on for 20 years old but I have owned other cars from that vintage: E30 BMW, mk2 Golf, Peugeot 205 with no rust whatsoever. This got me thinking. Do some cars in particular have a propensity to rust and why? Is it design-related or is it purely down to the quality of steel etc?

Elderly Alfa Romeos, Fiats, Lancias, Fords and BL products have a bad reputation for rusting but to be honest I don't associate these manufacturers with rusty cars now. I can't remember the last time I saw a rusty Fiat or a rusty car less than 10 years old for that matter. I see more rusty Fords than I do Vauxhalls and BMWs as well. Why?

Some rusty cars I see are surprising, for instance I have seen a lot of rusty late 90s Mercs recently and mk3 Golfs and the 1994-2000 MY Polo seem to be particularly bad as well. Even my cherished 1994 Corrado VR6 was starting to go rusty around the rear arches. Golfs are seen as more "desirable" than other cars in their class but I don't recall seeing many rusty Astras of that vintage. I don't recall seeing many rusty VWs before or after this period (with the exception of old Beetles and campers). So why does rust seem to be more of an issue on some cars than others?


eldar

22,813 posts

204 months

Tuesday 28th June 2011
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Availability of galvanised steel suitable to make car bodies out of.

RV8

1,570 posts

179 months

Tuesday 28th June 2011
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It's a shame cars rust. Just imagine how much easier classic ownership would be if they were impervious to corrosion.

JTXenon

27 posts

187 months

Tuesday 28th June 2011
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One of the reasons with the MR2 is that they put sponge in some of the body panels, they got wet and took a while to dry out. Just this week I prodded my mk1's front quarter panel a bit too hard and poked a nice sized hole in it. Anyway rust is lighter than metal :-D

londonplug

2 posts

149 months

Tuesday 17th July 2012
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I have had problems with rust on cars but have noticed that many cars well older than mine same make and other makes are completly rust free not even a pimple in the wheel arch
What i was told by somebody some time back is that this depends entirely on how long and how exposed car bodys hav estood in a car park of field prior to painting and assembly some bodys are delt with strait away while others sit for some time alowing rust to get into the metal and once its in there the cars fate is doomed to be a rust bucket so the car you get is just the luck of the draw
Do you think there is any truth in this as it certainly sounds feasable

ajb85

1,124 posts

150 months

Tuesday 17th July 2012
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Mercedes had terrible problems in the 90s with rusting wheel arches, due to poor paint I believe.

In my experience, Ford are the worst culprits. KAs - terrible! Absolute rot boxes! A 'modern day' 55 plate car springs to mind with an air-cooled floorpan and sills. You will ALWAYS come across rust around the petrol filler cap and around the rear wiper arm but that's just the norm with KAs. The boot floors on the older (pre 2001) shape Mondeo rot out. Mk1 Focus; bought and sold quite a few, a vast majority with rust issues, namely wheel arches and door bottoms.

Timberwolf

5,374 posts

226 months

Tuesday 17th July 2012
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Water traps (whether inherent or caused by drains that easily get blocked) exposed to bare metal are a major contributing factor - the main reason MX-5s end up rusting is the roof drains get blocked and water accumulates in the sills.

Particularly bad in areas which have some material increasing the water retention; either badly specified/weatherproofed sound insulation, or proximity to the road wheels allowing an unfortunate combination of chips to any paint or rust protection that may be present, and then mud to collect and hold water against the exposed metal. Rear arches of '90s Fords are bad for the latter one.

CapriV6S

421 posts

150 months

Tuesday 17th July 2012
quotequote all
Errm, would that be a built-in short-life to make consumers buy another car??? "Sorry sir, realise you bought a brand new car from us 2 yrs ago but come and see the latest improved model".

Theres no other reason why some manufacturers wont prevent rust-problms.

Hey, we managed to put men on the moon when Morris-Minors and Austin-1100s and Ford Anglias were the car of the day.

Or did we (??????)....

ajb85

1,124 posts

150 months

Tuesday 17th July 2012
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The one and only brand new car my mum had was an AlfaSud, it didn't make its first MoT due to terminal rot...

DonkeyApple

59,406 posts

177 months

Tuesday 17th July 2012
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Sometimes it's bad steel. Sometimes there is oxide already within the steel and there is nothing that can be done to stop it spreading from the inside out.

Often it is bad design in the car that leads to areas where dirt and water remain trapped/held as a corrosive force.

And then there is the corner cutting or errors on prepping surfaces or protecting them suitably.

okie592

2,711 posts

175 months

Tuesday 17th July 2012
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Mk4 golfs and boras rust on the front arch becuase theres foam behind it that gets wet from wheel spray and rusts from the outside out.

i assume its the same with other VWs, if its original paint and you fancy a fight they will still cover it under warrantee.

Roadrunner23

542 posts

203 months

Tuesday 17th July 2012
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French cars seem to be quite resistant to rust.

Ritchie335is

1,882 posts

210 months

Tuesday 17th July 2012
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I am that sick of expensive corrosion issues on my cars (I live on the coast)I have lost interest in them.
I am getting more and more into bikes now, easier to store inside, generally cheaper so I can have a few at the same time and none of the paintwork hassles.
Although, you are more likely to kill yourself.

anonymous-user

62 months

Tuesday 17th July 2012
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A lot of it is luck of the draw.

My old Skoda is almost rust free. It has no structural rust, just some surface patina on the underside that I am cleaning up and re-sealing.

Other examples of my car, from the same vintage are totally riddled with rust.

Why is mine special? I can't see any reason why, it just is.

okie592

2,711 posts

175 months

Tuesday 17th July 2012
quotequote all
Ritchie335is said:
I am that sick of expensive corrosion issues on my cars (I live on the coast)I have lost interest in them.
I am getting more and more into bikes now, easier to store inside, generally cheaper so I can have a few at the same time and none of the paintwork hassles.
Although, you are more likely to kill yourself.
get a jag xk all aluminium no rust for you

Stedman

7,291 posts

200 months

Tuesday 17th July 2012
quotequote all
okie592 said:
Ritchie335is said:
I am that sick of expensive corrosion issues on my cars (I live on the coast)I have lost interest in them.
I am getting more and more into bikes now, easier to store inside, generally cheaper so I can have a few at the same time and none of the paintwork hassles.
Although, you are more likely to kill yourself.
get a jag xk all aluminium no rust for you
Yup, just like the XJ....with lots of little bits of corrosion. Won't rust, will corrode. Same difference when you have to pay to sort it.

Ritchie335is

1,882 posts

210 months

Tuesday 17th July 2012
quotequote all
Stedman said:
okie592 said:
Ritchie335is said:
I am that sick of expensive corrosion issues on my cars (I live on the coast)I have lost interest in them.
I am getting more and more into bikes now, easier to store inside, generally cheaper so I can have a few at the same time and none of the paintwork hassles.
Although, you are more likely to kill yourself.
get a jag xk all aluminium no rust for you
Yup, just like the XJ....with lots of little bits of corrosion. Won't rust, will corrode. Same difference when you have to pay to sort it.
Ever looked at an older Defender up close!

ninjacost

980 posts

230 months

Tuesday 17th July 2012
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got a 500 quid 1996 106 with no rust at all , had an e39 m5 2001 that was rusting in quite a few places disappointing really for a premium brand car

Negative Creep

25,249 posts

235 months

Tuesday 17th July 2012
quotequote all
okie592 said:
Ritchie335is said:
I am that sick of expensive corrosion issues on my cars (I live on the coast)I have lost interest in them.
I am getting more and more into bikes now, easier to store inside, generally cheaper so I can have a few at the same time and none of the paintwork hassles.
Although, you are more likely to kill yourself.
get a jag xk all aluminium no rust for you
Or a Reliant Robin

Ritchie335is

1,882 posts

210 months

Tuesday 17th July 2012
quotequote all
Negative Creep said:
okie592 said:
Ritchie335is said:
I am that sick of expensive corrosion issues on my cars (I live on the coast)I have lost interest in them.
I am getting more and more into bikes now, easier to store inside, generally cheaper so I can have a few at the same time and none of the paintwork hassles.
Although, you are more likely to kill yourself.
get a jag xk all aluminium no rust for you
Or a Reliant Robin
Hmm, chassis rot on the Robin I bet!