Looking for advice on DIY rust repair and paintchips...

The place to pick up tips on bringing that showroom shine back to your E30.

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dodgem
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Post Wed Jun 07, 2006 9:09 pm

After looking through some of the posts here (notably Sheps Evo Sport) i've realised quite how shameful the paintwork on my 318iS really is :cry: I want to remedy this though, and since i don't get much free time, i'm planning on booking a week off work to really go to town on my car (it's the only way i'll get it done).

Trouble is i have no experience whatsoever in detailing or sorting out rust problems... so i'm hoping if i post a few pics of the problems you guys can help me out so i don't spend my week off figuring out how to fix her up and not get it finished. I want to finish the job off with the full Zaino treatment - going over it with ZPC, Z1, Z2, and Z8. I think i've read enough on here so far to do that ok (how long to ZPC the whole car by hand do you reckon?)

So correct me if i get this wrong, but i'll start off by washing the whole car down with a fairy liquid mix and lukewarm water then rinsing off and use Zaino clay to clean off the remaining surface muck (damping with water as i go) then rinse it off again and dry thouroughly. Next will be sorting out the rust areas and filling in chips - this is where i really need the advice:

How do i deal with the following areas of my car (bear in mind i have no idea about bodywork)?

Chips on the edge of a panel like here on the bonnet:

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or spot chips that have started to rust, and this really ropey attempt by the last owner to cover a scratch :?

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Scuff marks on the arch:

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Really nasty (for my car) bubbles of rust like this one at the back bottom corner of the drivers door:

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or this one under the windscreen rubber:

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Rust eating into the folded under section of the arch:

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Then there's the matter of a respray that didn't wuite make it to the edge of the panel :roll: along with a multitude of chips:

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And finally, this is what i hope to get rid of with the Zaino :D

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Ok, assuming i get all those defects sorted out and a nice flat paint surface...

First use ZPC all over to get rid of the myriad scratches and swirls, removing it from each panel as i go.
Then apply a fine layer of Z1 all over follwed by Z2 and allow it to dry to a haze before buffing it all off.
And finally wipe z8 into the paintwork all over the car :)

I'm assuming that of these last stages, using the ZPC is by far the longest part?

Thanks in advance for your advice - hoefully at the end i'll have some beautiful pics to post :D

Simon
maxfield
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Post Wed Jun 07, 2006 9:16 pm

Your scuttle will be rusty or maybe rotten by looking at that pic.

I'm sure c76jon will advise you about how to use zaino
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c76jon
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Post Wed Jun 07, 2006 9:47 pm

hi

ok i can give my advice if it will help you
dont touch the paint surface until you have sorted your rust problems
there is no point as any abrasive work you do sorting it will just remove the work you have done already

couple of pointers i see from what you wrote

when you clay then use a lubricant whilst clayying not just water

buy the zaino car wash and mix a nice soapy buket of it and keep panel wet with it.

zpc is gunna by hardest part.how long depends on what needs remedying and how long you are willing to take.prep is the key and the more time you take the better the results

by hand it will take a lot of effort.not because the zpc doesnt do the job but because compared to a porter cable orbital you will never be able to replicate 5000 rpm!! but it is achievable it just takes longer.

id say a fair bit of marks on arch will come out.you may wanna use z5 too as this contains a small amount of "filler" which will help disguise blemishes ie the deeper ones

less is best with zaino
thin layers work far better resist the tempatation to whack it on !!!

stone chips are repairable at home but the end result is dependant on the qulity of match with your touch up paint
get a good match and use this stuff below and you can make them almost invisible



http://www.langka.com/chip-scratch-repa ... 3af58f8be5

this stuff is incredible
they do post to uk and i recommend the kit or i use just the blob eliminator
this will tremove that excess touchup in your photo too

follow instructions to the letter and you will be amazed

if i can help anymore just shout

best of luck and only use microfibre for cloth for washing drying application and removal otherwise you will but as many marks into paint as you take out

hth

john
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rickk
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Post Wed Jun 07, 2006 10:23 pm

As my car is 20 years old and a daily driver I'm quite familiar with this kind of crap.. :?

Most important of all: treat the spots that rust *properly*. If you do a quick job (just cover them with paint) you'll find yourself treating the same spots over and over again - and they'll become much larger over time. If you don't remove rust completely it *will* come back.

First, you need to sand off the rust as much as possible.
For the small chips I found one of those glassfibre pentype things (Motip makes one I believe) the easiest to work with. Don't worry too much about hitting the surrounding paint (the *immediate* surrounding paint ofcourse ;)), this will help the new paint stick better and you can usually buff out these small scratches. Go sloooowly tough. You'll find that these small spots will take more time than the larger areas.

For the larger areas, get a dremel of some sort with various wire brushes and a few of these grinder stones to remove all rust. Also check for rust under the surrounding paint, as it can creep a long way hidden under the paint.

By now, If you've done things properly, you've probably removed quite a bit more paint (and metal) then you were hoping for, but remember that rust is like cancer, by cutting it out you're doing something good for the car.

Anyway, because you can never totally remove rust, you should shop for a rust-converter. There are various types, one is a combined primer/rust converter in a touch-up type jar, suitable for small spots, and the other one is just phosphorus (?) acid which you brush on, leave on for a couple of hours and rinse off with water - this is useful for the bigger areas.
What these products do is that they convert the rust to a "stable" oxide, the rust will turn black when converted and will stop spreading. A bit like how aluminium rusts, if you're familiar with that.

If the rust converter has done it's work, degrease, primer & and paint. Don't sand off the black spots left by the rust converter though.

I've found spraypaint more easy to work with even for touchups because it's thinner than the paint in those touch-up bottles - just spray some in the cap of the can and apply it with a small brush or a toothpick. Work slowly and in thin layers - try not to 'paint' it on, instead try to let a small drop 'flow' in the chip/scratch by capillary action. If your car is metallic (looks like it), you'll need to cover it with clearcoat too.

You're now probably left with 'bumps' instead of chips, flattening these is a kind of voodoo I'm still perfecting myself, but in general: wait for it to cure a little, wrap a rag around something like a creditcard, saturate the rag with an automotive paint cleaner (or thinner, if you're really couragous and need to clean up a big mess) and start polishing - don't apply much force, the idea is that you only want to hit the 'bump' and not the regular paint. With this technique I've managed to blend in some scratches perfectly, on others it didn't do anything, and on some I pulled out the touchup completely and had to start over again. Hit-and-miss kind of thing, but you might want to give it a go.

Your car doesn't seem to need it (but we'll see after you've sanded off all the rust :winkeye:), but for really large areas, go with spraypaint, mask off everything in the area. Try to paint one complete area that is 'naturally' delimited by trim or shutlines. If that's not possible (I don't think you can do much more than about 10 inches nicely as an amateur with a spraycan), never make sharp masks with tape: you will see the line *forever*. Instead, create a "crater" with tape and paper around the area and when spraying, try to minimize the time your spend around the edges of the "crater". However, never start or stop spraying on the exposed area, always start and stop on the masked area. If you need to cover with clearcoat, make a larger crater for the clearcoat and repeat - remember that it's not that hard to blend in clearcoat when polishing.
Furthermore, the usual applies, work in many thin layers, degrease etc, follow the instructions.
Also, use some filler and sand really really well because any imperfections in the surface are highlighted when you've got paint on.
After the clearcoat, the paint usually looks dull, but don't worry about this too much. Just let it cure for a few days and then use some cleaner, polish and elbow grease and it'll shine in no-time. Don't worry.

Some underbody coating before the paint on the edge of that wheelarch will prevent further stone chipping. While you're out there, remove the plastic splashguard and clean and closely inspect the area out there - dirt tends to clog the drainholes there and causes a lot of problems for both the outer panel and the floorpan.

The corner of the window is another typical E30-spot, and usually it means there's a lot more rust under the window trim... :oops:
Usually caused a combination of damage done when the window was replaced, and a slightly leaky window seal (next time you wash the car, keep an eye on that corner of the window and see if the water 'dissapears' )

That door seems to hang a little too low, might very well be the cause of that rust over there. Remember that by now it most likely rusts on the inside too, so you might want to get in there with rust converter and some protectant too. Unfortunately, from what I remember, that particular spot is almost inaccessible from the inside.. :roll:

You might be able to tackle the dodgy touchup with the "creditcard" strategy above, but usually this touchup paint sticks very well where it shouldn't, and not where it should (see also: superglue :wink:)

For the scuffmarks I'm still thinking of a strategy for my own car.. I think giving it a very light misting with spraypaint and a whole lot of buffing might do the trick.

Just some ramblings from my side, I'm in no way an expert, and I bet somebody here will come up with better advice, but still hope it helps..

Good luck,
Rick
dodgem
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Post Wed Jun 07, 2006 11:10 pm

Some great advice here guys, and i really appreciate the time taken to guide me in the right direction :) Feeling more confident about taking this job on already, though from Rick's reply it sounds like i may scare myself with the amount of repainting i need to perform after i've rid my car of it's rust :wink:

I guess (hope) it's one of those things where once you've started it becomes easier and more intuitive than it first appeared... but personally i'm looking forward to starting with the ZPC even though it'll take a long time, cos by that point the part i'm dreading will be over :wink:

As to the paint, it's Diamondschwartz metalic, but i haven't seen spray cans of this colour in Halfords - is there anywhere that will supply this colour in a can, or are there any other colours that match it well enough to use to respray a small area as Rick suggested?

Thanks,

Simon
Chris-W
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Post Thu Jun 08, 2006 6:29 am

Halfords will mix you an aerosol can of your colour. Just take them your BMW colour code (181 I think).

You'll need lacquer on top as well.
rickk
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Post Thu Jun 08, 2006 10:53 am

Hm, strange, I was able to find my colour (Royal Metallic Blue) easily in most autoshops. In any case, the stealer will have it for sure.

You'll want to make sure you have exactly the right colour as even with the right colour you'll notice differences.

And for the rest: practice make perfect, start somewhere out of sight and work your way to the more visible areas.
Chris-W
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Post Thu Jun 08, 2006 6:32 pm

The Halfords mixed aerosols are well worth paying the 2 or so quid extra over the pre-mixed stuff.

You get a decent quality cellulose instead of nasty acrylic & the nozzle even produces a decent fan.
dodgem
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Post Fri Jun 09, 2006 12:57 am

I'm usually quite sceptical of Halfords, though i have their pro-tools socket set (the big one) and it's great, so it's good to hear positive comments about their paint too :)

Cheers

Simon