Rear wheel arches, rust and a simple modification

[north-star]

Many thanks Television, another great post and a great help to all Mercedes owners

 

[tessa0146]

Great idea

Hi Television a great idea, my C class estate is just starting to show a finger nail size rust scabb on the rear arches, I have been trying to think of what to use on the edges of the arches, I was thinking of some sort of rubber u section, but you have come up with the mini trim, cant wait for the warmer weather, I have been washing around the arches twice a week throughout the bad weather to keep the salt away, has stoped it getting any worse so far keep up the good work, Griff

 

[television]

Hi Television a great idea, my C class estate is just starting to show a finger nail size rust scabb on the rear arches, I have been trying to think of what to use on the edges of the arches, I was thinking of some sort of rubber u section, but you have come up with the mini trim, cant wait for the warmer weather, I have been washing around the arches twice a week throughout the bad weather to keep the salt away, has stoped it getting any worse so far keep up the good work, Griff

It should work well,, I too was thinking of what one could use, I did no know that the mini trim came in black till I looked on Ebay, the good thing is one cannot see or notice it

 

[umblecumbuz]

Thanks too, from a relative newbie.

I was in bodywork for years, and the entire tone of this repair is excellent, and best practice for home repairs.

At the risk of digressing, I am also very glad to see that axle stands were used throughout. Car jacks are NEVER enough support.

A small tip: While the wheel arch is 'vacant' and Waxoyle is available, it pays to brush every metal component within reach with it (except exhaust and discs, of course), on the basis that every little helps.

 

[HelpThisDude]

Malcom, I thank you for your post
I will follow this with three of my arches that are rusting on the lip.
But one arch, done previously, rust has returned worse than before.
Is it possible that the reason the rear arch is so much worse then the front, is because two sheets of metal are spot welded there, and bent over into the lip? Could it be that the rust is between these sheets where we cannot get to, hence why it keeps coming back?

 

[television]

Malcom, I thank you for your post
I will follow this with three of my arches that are rusting on the lip.
But one arch, done previously, rust has returned worse than before.
Is it possible that the reason the rear arch is so much worse then the front, is because two sheets of metal are spot welded there, and bent over into the lip? Could it be that the rust is between these sheets where we cannot get to, hence why it keeps coming back?

The rears rust more than the front owing to the larger upturned lip that fills with mud, and this mud can stay wet for months on end and even contain salt. The front lip is never so wide as the rears and going around corners in the rain does wash some of this away.

I cannot be 100% sure of the rear arch construction as my other computer is down, but I will post back on this later.

There are welds where the arch liner is welded to the outer rear side panel, and when you try and fit the Mini plastic trim it needs to be forced open where it slides over the 2 panels that are welded. I t is a poor construction and only on the very latest models have MB changed the design.

 

[_Taz_]

did this mod today, well over the last few days...

plus points, the rear arches will last a bit longer....

bad bits, the mini trim really needed heating etc... and the last bit at the back kept on lifting up, ended up fitting a small rivet to the last bit & sealed with more waxoyl, silcoset glue...

oddly enough, the mini trim is quite tough & actually removes some of the hammerite i spent applying.

good mod though...will report back in a year & see how it lasts.

on a sidenote, I removed both wheel arch liners, jet blasted them, & the metal under it, primed it again, repainted etc....

lots of work but hopefully worth it !....

cheers Malc

 

[television]

did this mod today, well over the last few days...

plus points, the rear arches will last a bit longer....

bad bits, the mini trim really needed heating etc... and the last bit at the back kept on lifting up, ended up fitting a small rivet to the last bit & sealed with more waxoyl, silcoset glue...

oddly enough, the mini trim is quite tough & actually removes some of the hammerite i spent applying.

good mod though...will report back in a year & see how it lasts.

on a sidenote, I removed both wheel arch liners, jet blasted them, & the metal under it, primed it again, repainted etc....

lots of work but hopefully worth it !....

cheers Malc

Ideally one should leave the paint for a few days to dry out.

It is best to get the shape on the plastic mini trim something like the shape of the arch before fitting it, this can be done in hot water and holding while it takes up the new shape, or one can use a warm air gun, the there is the danger that you can kink the trim doing it with the warm air gun.

The trim is very tight as it has to be bent inside out from its normal, one can while still warm open up the gap using any type of blade

 

[Mic]

I did my rear near side yesterday and will be doing my rear off side this afternoon. My wheel arches are not bad having been ''done'' at MBUK's expense about a year ago but disappointingly there is evidence of returning corrosion right on the leading edge. I have a three years warranty on this work but I have elected not to go back with this but rather try to suffocate the corrosion by denying it access to hydrogen and oxygen......where corrosion has been in evidence I believe that it is never wholly eliminated but merely slowed......glacially I hope.

I think the trim that I bought must be different from the one that you have been using because it is very pliable and easy to fit....no pre-heating nor fitting difficulty whatsoever.

Anyway I spent a lot of time getting the lip perfectly clean before applying CT1 to the outside of the lip and within the trim itself in order to be certain of squeezing out any and all air as the trim was pressed into place from one end.....after fixing the trim into place I cleaned excess CT1 from the outer face of which there was plenty, by design, in ensuring air elimination. I did not remove the liners.....that will probably be something for next time which will hopefully be a few years away yet. I applied Waxoyl behind the newly fixed trim.

I am sticking with CT1 (I used it when sealing my seals at the bottom of my C pillars and along the bottom of the rear screen) because I believe it fulfills all the needed properties including being a gap filling adhesive. It can be applied to wet surfaces so if you have failed to dry off fully no matter.....does not shrink, remains flexible, antifungal, UV resistant and vibration resistant amongst others......time will tell of course.

www.CT1ltd.com

Mic

 

[television]

The 230 is easy to do as there are not too many twist in the metal, just 1 double seam to just the trim over.

 

[Dosco]

I did my rear near side yesterday and will be doing my rear off side this afternoon. My wheel arches are not bad having been ''done'' at MBUK's expense about a year ago but disappointingly there is evidence of returning corrosion right on the leading edge. I have a three years warranty on this work but I have elected not to go back with this but rather try to suffocate the corrosion by denying it access to hydrogen and oxygen......where corrosion has been in evidence I believe that it is never wholly eliminated but merely slowed......glacially I hope.

I think the trim that I bought must be different from the one that you have been using because it is very pliable and easy to fit....no pre-heating nor fitting difficulty whatsoever.

Anyway I spent a lot of time getting the lip perfectly clean before applying CT1 to the outside of the lip and within the trim itself in order to be certain of squeezing out any and all air as the trim was pressed into place from one end.....after fixing the trim into place I cleaned excess CT1 from the outer face of which there was plenty, by design, in ensuring air elimination. I did not remove the liners.....that will probably be something for next time which will hopefully be a few years away yet. I applied Waxoyl behind the newly fixed trim.

I am sticking with CT1 (I used it when sealing my seals at the bottom of my C pillars and along the bottom of the rear screen) because I believe it fulfills all the needed properties including being a gap filling adhesive. It can be applied to wet surfaces so if you have failed to dry off fully no matter.....does not shrink, remains flexible, antifungal, UV resistant and vibration resistant amongst others......time will tell of course.

www.CT1ltd.com

Mic

Have you any idea what you have started now

 

[Mic]

The 230 is easy to do as there are not too many twist in the metal, just 1 double seam to just the trim over.

Must be easy if I am having a go.

Mic

 

[Mic]

Have you any idea what you have started now

I know.....I have surprised myself.....I have resolved to do the front wheel arches..... even though they are aluminium they can ''corrode''. Also a matter of ''completeness''.

I need new rubber on the fronts soon which I have on another set of wheels.....I will do the arches when I switch the wheels.

Mic

 

[television]

I know.....I have surprised myself.....I have resolved to do the front wheel arches..... even though they are aluminium they can ''corrode''. Also a matter of ''completeness''.

I need new rubber on the fronts soon which I have on another set of wheels.....I will do the arches when I switch the wheels.

Mic

There is only a small lip on the fronts, and they do not seem to hold much mud, no harm in doing it any way

 

[carnut13]

I know.....I have surprised myself.....I have resolved to do the front wheel arches..... even though they are aluminium they can ''corrode''. Also a matter of ''completeness''.

I need new rubber on the fronts soon which I have on another set of wheels.....I will do the arches when I switch the wheels.

Mic

This is from a man who wouldnt even admit to washing his car a few months ago

The power of the Forum and Peer pressure is a wonder to behold:lol:

 

[MarkF]

I'm going to do this to mine, signs of rust on the arches. Dose anybody know of a good chemical rust treatment I can use before I paint, the stuff halfords sell is not that good.
I also have signs of rust starting on the bottom of the doors.

 

[Dosco]

This is from a man who wouldnt even admit to washing his car a few months ago

The power of the Forum and Peer pressure is a wonder to behold:lol:

I have it on good authority that Mic with his new found technical expertise will sort out all the rust on yours Steve, why not give him a call

 

[Dosco]

I'm going to do this to mine, signs of rust on the arches. Dose anybody know of a good chemical rust treatment I can use before I paint, the stuff halfords sell is not that good.
I also have signs of rust starting on the bottom of the doors.

Hi Mark check out POR15 I seem to recall this being raved about on here and several other motoring forums.

 

[Silver_Star]

I'm going to do this to mine, signs of rust on the arches. Dose anybody know of a good chemical rust treatment I can use before I paint, the stuff halfords sell is not that good.
I also have signs of rust starting on the bottom of the doors.

I would have a look at the BiltHamber products. The Detyox Gel and the Electrox Primer.

 

[Joseph Brown]

Is the link below the right product for the waxoil?

http://www.halfords.com/webapp/wcs/..._-Product_Details_Zone_1-_-Blank&iozone=PDPz1

Pretty pricey, is there a smaller amount?