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Rear Wheel arch rust: cut or clean up
bikecarbfred - 12/8/20 at 08:09 PM

I've bought some after market plastic arch trim as on these polo's theres a lot of rust on the rear arch.

If I remove the rust and get it to steel from the outside, do I have to remove the rust from the inside?

Would this mean there is no option but to cut out the rust and re-weld another arch in?

Where would I get these arches from, although i'd rather find a easier option. Thanks




nick205 - 13/8/20 at 08:06 AM

IMHO I'd cut away and replace. In the photos it looks as if the rear end of the sill has corroded as well. You could go th whole hog and replace the whole sill, but I suspect the car's not worth spending the money on that level of rust chasing.

Ultimately I guess you have to ask yourself how long you're going to keep the car and will chasing some of the rust away be enough. How much will the plastic cover? If you're going to have the car until it's end of life days then chase the rust with minimal effort and cost and cover with the plastic. Make sure the end result is MOT passable though - nothing worse than weekends of work to be given a NO!

Mr Whippy - 13/8/20 at 10:31 AM

imo I would say the car is not worth welding, if it's that bad there, then there will be much worse hiding. Unless you plan on keeping the car a long time I'd just do a bondo repair and plenty of oil or something like it injected into the panels from behind to stop future rust. None of it looks structural or an MOT failure other than sharp edges. Personally I'd weld in new arches but if your asking then I'm assuming you could not do it yourself and garages charge way too much and usually do a dreadful job.

You'll have fun matching that metallic paint...



[Edited on 13/8/20 by Mr Whippy]

nick205 - 13/8/20 at 01:10 PM

quote:
Originally posted by Mr Whippy
imo I would say the car is not worth welding, if it's that bad there, then there will be much worse hiding. Unless you plan on keeping the car a long time I'd just do a bondo repair and plenty of oil or something like it injected into the panels from behind to stop future rust. None of it looks structural or an MOT failure other than sharp edges. Personally I'd weld in new arches but if your asking then I'm assuming you could not do it yourself and garages charge way too much and usually do a dreadful job.

You'll have fun matching that metallic paint...



[Edited on 13/8/20 by Mr Whippy]



Yup - garages certainly charge a lot for that sort of work and very often with questionable results as well. If they set out to do a proper repair job on it they'll often end up taking half the car to bits at which point it's time to replace the car anyway.

coyoteboy - 13/8/20 at 03:16 PM

FWIW I chased much less nasty rust on the arches of my ST185 and stripped it all back to the bone, cut out bits that were dead and welded in replacements, treated it, primered it, sprayed it with 2-pack and 2 years later it's back.

I hate rust.

bikecarbfred - 13/8/20 at 09:56 PM

this car i plan to keep for a very long time.

steve m - 13/8/20 at 10:35 PM

imo I would say the car is not worth welding, if it's that bad there, then there will be much worse hiding. Unless you plan on keeping the car a long time I'd just do a bondo repair and plenty of oil or something like it injected into the panels from behind to stop future rust. None of it looks structural or an MOT failure other than sharp edges. Personally I'd weld in new arches but if your asking then I'm assuming you could not do it yourself and garages charge way too much and usually do a dreadful job.

You'll have fun matching that metallic paint...


Rust, is metal going back to its original state, as in ore, once rust is in the area, no matter what, it will come back

steve

Mr Whippy - 14/8/20 at 07:39 AM

quote:
Originally posted by bikecarbfred
this car i plan to keep for a very long time.


Unfortunately it seems the car thinks otherwise

Joking aside yes you'll have to replace the inner & outer skins around that area. There's https://www.carbodypanels4u.co.uk/ or ebay and a few other sites to get the panels but they tend to be quite expensive. One alternative is to go to the breakers with a chisel or saw and cut out the rear quarter of a car that isn't rusty there, a lot easier to do than you may think. I've sliced up whole cars with nothing more than a sharpened bolster chisel and lump hammer it doesn't take long.

Once replaced you can pour hot oil in behind the panel and that will soak into the gaps and stop it rusting again.

bikecarbfred - 14/8/20 at 04:33 PM

£35.00 each for panels. Not bad.

I have a local welder who would do it in garage. If he bodges up weld, can I use filler to make sure it's smoothened out.

Like you lads said. Your leaving it to others to get a fine finish.

bikecarbfred - 15/8/20 at 06:52 AM

Hi I have worked out as I am already removing the windows and replacing them wit lexan glass that it might be cheaper just to buy the panel. £120 for one panel.

is that much of ball ache to replace;; doesnt seem like it from looking at the below pic;

EDIT: just realised its a 4 door . dont think there is a 3 door version . its part of the body. i will give the welder a ring.



photo hosting sites

[Edited on 15/8/20 by bikecarbfred]

[Edited on 15/8/20 by bikecarbfred]