And so it begins.. tackling r230 wheel arch rust.

[Jim2]

.. So I am clearly not a professional videographer, but here is a quick clip I recorded yesterday. Sorry it's a bit shaky at times, as the gimble on the camera has a mind of its own and I didn't want to knock it of any surfaces.

You will also see that on the arches towards the front end of the car that run perpendicular to the road are both a bit dodgy looking. They will need to be evened off and made a bit more aesthetic as they will be visible from the road.

Oh one note: In the video I say it's all clean and sound like it's finished but there were a few bits needing further treatment and this was prior to that. My mistake in the video.

One of the problems working in that area, and the chief cause of it having rust is that its where the inner and outer panels are spot welded together...you can even see some of the welds...they are at regular intervals along the line. and in the tiny gap's between the welds, water lodges and the corrosion begins,,,,so as I explained earlier, when air / water meets metal, rust is the result. Do what you are doing, and seal it as best you can. You will be fine.

 

[Rockron]

One of the problems working in that area, and the chief cause of it having rust is that its where the inner and outer panels are spot welded together...you can even see some of the welds...they are at regular intervals along the line. and in the tiny gap's between the welds, water lodges and the corrosion begins,,,,so as I explained earlier, when air / water meets metal, rust is the result. Do what you are doing, and seal it as best you can. You will be fine.

Often the best that manufacturers can get between spot welded sheet steel, is 'weld through primer'.
So, even if some form of post-weld rust preventer is sprayed/injected/dipped into the cavity it isn't
guaranteed to get on those steel surfaces between the spot welds, even via capillary action. So the result inevitably
is that these small area only have weld thru' primer (mediocre) rust protection, hence why it's so common to find
the beginnings of rust starting at spot welds. I'm near certain that even weld thru' primer burns off
in the proximity of the molten metal when welded, a tiny area maybe, but we all know that's all it
takes!!

 

[Jim2]

Often the best that manufacturers can get between spot welded sheet steel, is 'weld through primer'.
So, even if some form of post-weld rust preventer is sprayed/injected/dipped into the cavity it isn't
guaranteed to get on those steel surfaces between the spot welds, even via capillary action. So the result inevitably
is that these small area only have weld thru' primer (mediocre) rust protection, hence why it's so common to find
the beginnings of rust starting at spot welds. I'm near certain that even weld thru' primer burns off
in the proximity of the molten metal when welded, a tiny area maybe, but we all know that's all it
takes!!

Agreed 100%. I've used weldable primer on panel's that I've spot welded together. and as the weld itself ( by very definition ) involves raising the temp of the metal to its melting point to fuse it together.....there is no primer can withstand that...., But major strides have been made in producing metal alloys that resist rust. I worked on a 2014 Skoda Octavia, and what ever was in the metal composition, it was very difficult to drill holes in it, so I'm pretty sure that this is one of the newer generation of metals...had a 2003 A6, which did not have any naturally occuring rusting, such as Conor is finding in his MB. I think back in the 70's Volvo and Saab were the first to give a 10 year anti rust guarantee on their vehicles. On my W212, I'm not expecting to find any rusting in the usual sites on my car. We will see.....

 

[Rockron]

Agreed 100%. I've used weldable primer on panel's that I've spot welded together. and as the weld itself ( by very definition ) involves raising the temp of the metal to its melting point to fuse it together.....there is no primer can withstand that...., But major strides have been made in producing metal alloys that resist rust. I worked on a 2014 Skoda Octavia, and what ever was in the metal composition, it was very difficult to drill holes in it, so I'm pretty sure that this is one of the newer generation of metals...had a 2003 A6, which did not have any naturally occuring rusting, such as Conor is finding in his MB. I think back in the 70's Volvo and Saab were the first to give a 10 year anti rust guarantee on their vehicles. On my W212, I'm not expecting to find any rusting in the usual sites on my car. We will see..

I actually think that often the drill and fill weld method of pseudo spot welding, (as those of us with just a MIG
or TIG welder etc. might carry out), to actually resist rust ravaging better than the factory or professional
purpose made clamping electrode type produces. The spot weld itself adds no metal and thins out the steel
at point of contact, further, the force/heat distorts the steel, hence adding to the dimpled thinning effect.

However maybe it's just wishful thinking, my spot MIG welds probably take 10 times longer than the
pro. with specialised gear would take.....I've feel got to justify the effort somehow!

Way back in prehistoric times c. 60s some Brit. cars were made from a magic substance,
Brights or was it Brites Steel? It was renown for being tough and springy and rust resistant..oh yeah!,
panel beaters loathed having to work with it apparently. Some Rover cars IIRC were made from it.
I think it was mild steel alloy combined with other metals!? producing a new alloy, not s/steel so
probably not copper or chrome. Well it was a start I guess.

I think what you're stating if not proving, is that the price you pay for a vehicle is not necessarily
commensurate with it's ability to resist rust. I'm thinking eg of all those +12 year old rust free unpampered
Citroens and Pugs running around (ok, when not broken down!), and all those MBs in body shops
having wheel arches and more welded in!

edit: Bright steel = mild steel rolled at room temp. so no additional metals alloyed, alters the steels properties ie tougher but more brittle.

 

[Conor]

Just a quick update on this as I have been a little quiet lately.

To cut a long story short.. any of the decent body shops I went to around my area didn't want to know about the job I was doing. They simply weren't interested in doing just the paint - they wanted the whole job of doing the rust and prep etc. Which is beggars belief. I imagine they could have a nice tidy business if all they were doing was prepping surfaces and painting all day long..

Anyway, I have been quite lucky to get connected with the guy who has sprayed my mates old VW camper up the country.

His attitude was simply that I would make a mess of prepping and even using 2K Epoxy primer out of an aerosol was bad. He invited me to bring the car to his workshop, where I could work on it there for a couple of days, under his guidance and then he would paint it when ready. His pricing seemed reasonable too, compared to the £1k+ for the job in London.. which was basically them telling me to get lost.

I will be driving the car up to him at the end of this week or Monday and get cracking. I'm excited about it.

 

[McDonald]

I have been quite lucky to get connected with the guy who has sprayed my mates old VW camper up the country. I will be driving the car up to him at the end of this week or Monday and get cracking. I'm excited about it.

Best of luck with it Conor. Hope it turns out well. I think you're in Eire for August, so assume you won't be going to Beaulieu on Aug 23. If you were going we could have compared wheel arches. Mine's going in on July 20.

 

[Conor]

Best of luck with it Conor. Hope it turns out well. I think you're in Eire for August, so assume you won't be going to Beaulieu on Aug 23. If you were going we could have compared wheel arches. Mine's going in on July 20.

Thank you, and that is correct, I won't be around

Lol, the thing with arch repairs is that they all look great initially.. we can compare in 18 months time LMAO

 

[00slk]

Gosh, when I started in the panalbeating field it was oxy/acetylene welding and braising, and if you were competent enough electric welding on the Land Rover and truck chassis, learning to mig weld in the 70's because car steel was changing to more high tensile metal. When working in the panel shop for AUdi/VW they were offering 5 year rust and paint warranty and any panel replacements such as rear 1/4's sills, door post etc had to be pre primed with weld primer (which I thought was a load of poopy because as mentioned earlier burnt away) but we still had to use it and any other preventative treatment for the customers car, which incidentally used to be many celebrity owned. I was only there for 5 years and can say never had a come back due to rust or paint failing. Though I must say 'the VW Golfs and the first Sorroco were very well sealed with there under body sealant.

 

[Conor]

I have just realised I never posted any pics of the professional part of this repair.

 

[Conor]

 

[Conor]

...Placeholder here to say I need to further update this post with the results now that we are 3 years on.

Please @ me if you read this in a few days and I have posted, and you want to see..