Bad rusting stone chips please help

[Nigel Foster]

After being laid up with ill health and my 2015 Mazda left standing I've found it's got a number of "chips" on the roof.. actually caused by bird droppings.. some rusting already with disturbing cracks / legs working under the paintwork. It's all happened quickly like 3 weeks..

I'm reading through past posts but please can anybody advise how to deal with these whilst I can my health is not great

I feel like I might have to take the paint back considerably (to 5p /10p size for a couple) with.. fibre glass pencil (dremel?).. then use a rust inhibitor (degreaser? application of kurust?).. paint in with brush.. clear coat??.. lacquer?? wet sand ??

Any suggestions as to specific products and how far to cut into the paint greatly appreciated

I'm guessing a respray of the roof may be required long term, would anyone have an idea of cost?





Thanks for reading..

[Nigel Foster]

Appreciate the comments!

I put vaseline over the spots to prevent moisture ingress for now, but ofc that won't stop the existing rust from encroaching further.

vikingaero said:

Anything you do now will help the spread of rust/damage.

This is where I'm unsure what to do.

A detailer today recommended just picking out the visible rust, applying rust convertor.. then he would do the paint touch up and lacquer for me and polish out the 'legs' and the whole roof. He reckoned that would look fine and be good for 3-5 years?

My concern is.. where the 'legs' / crackling paint is, is that indicative of rust under the paint (..which would then return quickly bubble quickly and spread.. going against what detailer said)? Or is it stressed paint?

He reckoned if I tried to pick under those bits, I'd likely just cause more damage and make the problem bigger, perhaps lifting the paint further unknowingly, allowing more air to contact steel etc.

So looking at the pic here he's just suggesting working back the yellow area.

Is there a consensus for that approach?

I thought I might need to lift the paint marked in grey to get at all the rust, but I imagine with how these things go I'd end up working back to the red area.. which is about the size of a fingernail and when touched up would look ****.

Belle427 said:

I’d guess a roof re spray would be close to £300, depends how much time and patience you have really.

Only had one quote so far, £800 for respray would involve window out and stripping back headliner to remove sharkfin aerial.

There's no way would I attempt this myself.

Edited by Nigel Foster on Monday 13th June 20:06

[Nigel Foster]

Thanks @paintman

I wish I could make a decision.. there's no easy option here is there. 🙄

Feel this is going to be an expensive lesson : if you're going to be ill make sure you get someone to wash your car.

[Nigel Foster]

I wish I could "like" posts as all contributions are appreciated!

I've spoken to 3 bodyshop guys and 2 detailers (all of whom recommended by trusted 3rd parties) and received mixed advice.

All good guys, none hustling for business..

• 1x detailer recommended working back all the rust, priming then wrap the roof.
• 2x bodyshop guys said window out for a respray maybe £1k+.
• 3rd bodyshop guy said he could do a respray for £400.

He and 2 others recommended as per @paintman :

Take the visible rust back (so approx to the yellow area) .. apply kurust etc.. paint.. lacquer and buff out the 'legs'. Then monitor.

All reckoned it would hopefully be years before issue as it's sealed from the air, and if bubbling does appear, nothing lost.. go to plan B and respray. So I'm going to do this but..

A respray for £400 to 'eradicate' the problem sounds decent.

Is it a case of ' you get what you pay for '?

He comes recommended to me by three trusted people, and unlike the other two was willing to do it without removing the screen. I'm not sure why the screen must be removed.. seems to introduce more risk, and pulling the window seal forward seemed to allow access to the roof panel to spray.

Any thoughts?

[Nigel Foster]

Thanks again, paintman

One of the bodyshop guys was showing me what he would if it was his car, he buffed the legs off of one of the marks till they weren't visible, it didn't expose any rust tracks or primer it looked normal again. I think it might look worse in the pic than IRL? He thought I was being a bit OCD about the whole thing.

I'm actually wondering if there is rust under them legs.. because I couldn't find any pics of similar looking chip marks online. I've seen similar marks from where bird muck lime has crazed the paint on the surface, and the mark in the pic was under bird poop. Maybe lime + proximity to a stone chip produced crazing on the surface.. I'll defer to your judgement, but will find out soon enough...

None of the chips are close enough to the window to have rust from them reach the edge / seal, and I don't see any bubbling there.. which I why I wondered why it's necessary for the screen to come out... (if it can be painted right to the edge, which in my layman opinion i would think so, as there's enough of a lip to pull the seal forward and work around it slightly).

[Nigel Foster]

CarCrazyDad said:

Doesn't really look like original paint on the roof either to be honest ..

I've wondered this..

One other panel looks flat to me like it's been resprayed, no 'orange peel' effect, but I don't know really.

[Nigel Foster]

That's good to know Belle..

The bodyshops I spoke to that insisted on it, it seemed to relate to warranty 'protocols'.. ie it must be done screen out for them to issue their warranty - company policy.

But the warranties didn't cover rust anyway...

[Nigel Foster]

paintman said:

Lift the edge of the seal where it sits on the paint with a plastic filler spreader & push a length of single plastic covered wire under the seal.
This will keep the seal edge up while the panel is being painted. The paint will go under the seal.
Once painted & cured remove the wire & the seal will sit on top of the new paint rather than there being a visible edge where the seal is.

Great tip, thank you!

V8covin said:

If I were doing it I'd spot sand blast the rusty areas to be sure it's all gone..

Well I see this is something you do do professionally.. sent you a PM!

If I go for a local respray.. I'm not sure how to choose. I've had four quotes from £300 to well over £1000. The person with the most recommendations (four different people now) said £400, and he talked the most sense..

Any recommendations in the NW..?

I'm looking to get 4 to 5 years out of the car..

[Nigel Foster]

I've spoken to Tony and seen his work good call @v8covin!