# BMW M3 Cabriolet (E46) - Major Paint Correction!



## Dave KG (Feb 23, 2006)

I'm going to format this write up a little differently. Still lots of pics, I still believe they are the best way to showcase the quality of the work but I've cut the number down a bit. However, I am going to spend the first bit of the write up detailing the processes (so if you're not interested in this scroll to the pics  ), then the second bit showing the work by pictures and then the artistic after shots at the end so if you just want to see the shiny car, scroll to the bottom  I am also going to focus this write up on the paint correction stage where the vast majority of time was spent on this particular car.

So - having washed, decontaminated the car and rolling it in ready for the paint correction, the finish was assessed using all light sources available to us, paint thicknesses measured looking for inconsistencies and thin spots (a few found, see later  ), and after trialling various combinations across the car we settled on the following product combinations, applied in the following ways.

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For heavy correction work (most of the car!) where the paint thicknesses allowed: 3M Fast Cut Plus on a 3M Orange Cutting pad, or Chemical Guys Hexlogic Yellow Cutting pad, applied as follows:

> Spread the compound at 600rpm
> Begin working at 1200rpm, until residue evenly spread
> Work at 2000rpm with moderate to heavy pressure until the defects removed or residue clear.

Fast Cut was chosen for its consistent performance as an aggressive compound, delivering excellent correction of severe marks.
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For correction where the paint was thinner and compounding would be unwise: Menzerna PO85RD3.02 Intensive Polish on a 3M Yellow Polishing pad or Chemical Guys Hexlogic White Polishing pad, applied as follows:

> Spread at 600rpm
> Begin working at 1200rpm, building a bit of heat in the panel to evenly spread the residue
> Work at 1800rpm until the residue goes clear, moderate pressure getting lighter towards the end of the set
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For combined hologram removal and refinement: Menzerna PO203S Power Finish on a 3M Yellow Polishing Pad, applied as follows:

> Spread at 600rpm
> Begin working at 1200rpm, building a bit of warmth in the panel so the lubrication spreads evenly
> Work at 1500rpm, moderate pressure for a few steady passes
> Work at 1800rpm, moderate pressure for a few passes until the residue begins to go clear, steady machine movements keeping the temperature of the panel to luke warm
> Work at 1500rpm, light pressure until the residue goes fully clear
> Refine at 1200pm, light pressure and slower machine movements to refine out any light machine marring
> Jewel at 900rpm, supporting the weight of the rotary for very light pressure and slow machine movements for a couple of passes
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We found Power Finish a superb product for hologram removal and refining on this particular paint (hard as assessed by removal rates), and with a long work time and attention paid particularly to the refining stages of the set, it finished down beautifully meaning no need for further refining of the finish (no improvement seen from PO85RD Final Finish).

On to the pictorial descriptions of the detail:

Starting out with the bonnet, before shots first of all assessed by the Sun Gun (note the swirls, and also holograms from previous polishing efforts...):














































And also assessed under the strip lighting - now see the deeper marks in the finish, bleeched out by the Sun Gun above:














































Using just the strip lights for now, a before and after shot of a specific region to show the correction level achieved (note, still the odd deep mark remains after two hits of Fast Cut, which was deemed all that was safe on this finish). Before:










And after correction:










More after shots of the bonnet from the strip lighting to assess the correction (again, look out for the marks that still remain - perfection would be nice, but on this car, not achievable without the risk of blowing through the clearcoat - a risk no detailer should ever take!)...





































And after shots using the Sun Gun to check the finish clarity (and also assessing the correction level too...):























































Passenger side wing before:














































And after...














































Passenger door before (note the holograms from previous polishing efforts which raise an eyebrow - how much paint have we been left with?):














































How much paint?!










Tread carefully - if you are wondering why there are still the odd mark left here and there, this is the answer as to why!

Afters:














































Rear three quarter, passenger side before:














































And after:























































Bootlid before:
































































And after...
































































Driver's side rear three quarter before:























































And after:























































Driver's door before:














































And after:























































Driver's front wing before:























































And after:























































Following correction, the paintwork was protected with Chemical Guys 50/50 wax, trim with Migliore Trim Protectant, tyres with Espuma RD50, wheels with FK1000P, arches with 3D Ultra, glass with Autosmart Glass Clear and exhausts with 3D Metal Polish.

The end results, outside in the evening light:




































































































Another enjoyable detail, its always nice to see your hard work rewarded with a happy owner and some nice after shots! As always, I hope this write up has proved helpful and useful - any questions, feel free to ask :thumb:


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## GoldCoast (Dec 7, 2008)

Excellent write up, and a fantastic results as always.


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## OzMoSiS (Jun 19, 2009)

i love your writeups, they're always so 'educated' and helpful :thumb:


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## pauly87 (Jul 19, 2010)

car looks amazing. really enjoy looking at your threads. always get brilliant results


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## twoscoops (Mar 26, 2010)

Simply Sublime!!! Tim


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## robsonj (Apr 14, 2007)

its a mans sport machine polishing paint that thin lol


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## Adam D (Nov 3, 2009)

Great work Dave.

Was the paint cosmos metallic black? Looks the same colour as my old E46.

After reading the thread I am still slightly confused about "hard" paint. I know this refers to the clearcoat, which is part of the paintwork and normally a high thickness reading means hard paint.

However, you then talk about removal rates, so are all clearcoats the same? You could have a car with a reading of 200 which some would say is hard, but after one pass with a low cut polish it drops down to 100 indicating you have taken off loads of clearcoat and the paint, based on a thickness reading, has gone from hard to medium.

But, a mega-hard clearcoat, if there is such a thing, would only lose 10 from the same polish/pad combo?

Am I right?

Cheers

Adam


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## Dave KG (Feb 23, 2006)

Adam D said:


> Great work Dave.
> 
> Was the paint cosmos metallic black? Looks the same colour as my old E46.
> 
> ...


Carbon Black I beleive - looks sort of blue when the sun shines on it 

You are right - a "hard" finish is one which requires more aggressiuve combos to remove a certain amount of paint compared to a soft finish, which means the defects (which are always a given depth) are harder to remove. This is why, a finish with harder paint is harder to correct, as you need more aggressive combos to get the required removal to remove the defects


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## caledonia (Sep 13, 2008)

Hi Adam.
I think you have got the wrong end of the stick m8.
Paint thickness reading does not constitute paint hardness.
The total reading in the gauge is the total thickness of all 3 layers in this case, and has nothing to do with hardness.
There is only one sure way to gauge hardness of the paint and this is with the removal rate and polishing combos.
For example after the initial set and you removed say 4 microns of paint with a finish pad and finish polish you would be very fullish to venture anywhere near the car with a heavy compound and a cutting pad. The removal rates regardless of over all thickness would be to extreme. 
Hope this help clear up any misunderstandings you have.
Gordon.


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## Adam D (Nov 3, 2009)

Thank you Dave and Gordon.

That does explain what a "hard" paint is.

And, how important a gauge is when doing a full scale correction on your paint.


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## Dave KG (Feb 23, 2006)

Adam D said:


> Thank you Dave and Gordon.
> 
> That does explain what a "hard" paint is.
> 
> And, how important a gauge is when doing a full scale correction on your paint.


Essential, in my opinion. Its not the exact readings that matter to me, it is how consistent the paint is - we are always looking for inconsistencies, for example thick regions that point to respray work or very thick regions pointing to filler having been used, or thin regions pointing to previous polishing... the gauge provides a wealth of information, and it is info I would regard as essential when it comes to fully assessing a car for machine correction


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## Mr Face (Jan 22, 2009)

Dave / Gordon

As always, a master class indeed. 

Huge thanks for taking the time to both post so many pictures and write up such an indepth paint correction.

Great work fella's 

Mike & team :wave:


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## Sharpy (Mar 25, 2007)

very nice write up as usual, but bloody hell dave did you put enough pics up? even on 20mg broadband it took ages to load them all and scroll through all pretty much of the same thing of before and after! !


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## gb270 (Aug 22, 2008)

Great turn around


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## Dave KG (Feb 23, 2006)

Cheers guys for the kind words 

Re: the number of pictures, I do appreciate that I tend to post a lot, my reasoning being that I find this the best way to show the _consistency_ of the finish achieved... its easy to snap the odd pic here and there where the finish looks good, which is why I like to put quite a few images up to show the consistency of the finish using different light sources in telling the story of the detail and to try and give as honest a review of the work achieved as possible. It would be easier for me to put up less; less time spent resizing, blanking number plates, uploading, etc - but I like to put the effort in to put up a good deal of pictures to better tell the story of the work achieved (in my opinion). Hopefully that makes sense.


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## SimonBash (Jun 7, 2010)

Given that extremely low PT reading following previous work were you not suprised that no strikethrough was evident?


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## Dave KG (Feb 23, 2006)

SimonBash said:


> Given that extremely low PT reading following previous work were you not suprised that no strikethrough was evident?


Some of the readings did certainly raise an eyebrow yes, but thankfully there was no strike through evident on the car and no evidence of dangerously thin clearcoat either which typically manifests itself as lots of tiny little pin pricks in the surface.


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## PaulN (Jan 17, 2008)

Nice write up..... i guess this is a pure correction writeup as opposed to a full correction detail write up as no wash stage photos?

I enjoy both but get more out of this type as you went through the polish, pad and sets.

Like ive said before a good video of a full machining set on a section of panel would be great also to see your speed of movement and number of passes.

Its bonkers how blue that looks under lights compared to outside.... :thumb:

Cheers

PaulN


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## Dave KG (Feb 23, 2006)

PaulN said:


> Nice write up..... i guess this is a pure correction writeup as opposed to a full correction detail write up as no wash stage photos?
> 
> I enjoy both but get more out of this type as you went through the polish, pad and sets.
> 
> ...


Cheers 

Yup, that was the aim of this write up and there's a couple of this type to come along too, along with a couple of writeups detailing other aspects of the process too... Trouble with the wash stage is I always worry about my D90, and snow foam!

Video - I've recorded one of a Fast Cut Set on a BMW X5, so keep your eye out for that writeup... other sets we are working on, too, so its a work in progress.


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## M.J (Mar 17, 2010)

brilliant turn around there , going back to removal rates , say for instance as said by Caledonia circa 4 microns at the start of the set with finishing combo,s would be heeding towards a big no no for compounding in these area,s . 

Am i correct in saying the very top layer of the surface your working on would initially be subject to high removal rates (depending on combo) relative to paint hardness of course

What i,m getting at is how many microns of 'soft intial' paint would you consider when it comes to concluding hard/meduim paints after testing an area . 

Staying with this , what sort of readings did you see before and after? 

cheers 

Mike


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## Rick74 (May 31, 2009)

Another excellant job and another black beemer lol


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## alx_chung (Aug 13, 2006)

Great write up as usual Dave!!
Keep up the good work!
Alex


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## caledonia (Sep 13, 2008)

M.J said:


> brilliant turn around there , going back to removal rates , say for instance as said by Caledonia circa 4 microns at the start of the set with finishing combo,s would be heeding towards a big no no for compounding in these area,s .
> 
> Am i correct in saying the very top layer of the surface your working on would initially be subject to high removal rates (depending on combo) relative to paint hardness of course
> 
> ...


Mike 
In the example I have given I mentioned after the initial set, as you have rightfully pointed out the initial set would have a higher than normal removal rate. Due to the upper most layer being damage by weather conditions, UV damage and the like. This upper layer is essentially a dead layer of paint and very brittle by nature. So the first set will remove this completely and expose a new virgin layer of either paint or clear.

Unfortunately you cannot gauge how hard the paint or guess the removal rates, as you do not know how the car has lived its life. Was it protected fully. Was it topped up with a good quality LSP and the like.

Always try and monitor the remove rates with every pad and polish combo and gauge the level of correction as a comparison.
Sorry I cant be more helpful.
Gordon.


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## 123quackers (Jan 29, 2009)

Dave Fk100p use seem to use on the wheels often, as I have seen many people do on this forum.. Some like it on the car too..

Colli 476s seems from what most people on here deem to be one of the most durable waxes out there yet it's not used much on wheels.. have you done any tests with say FK1000p on one and Colli476s or 915 845 etc on durabillty?

The 3M orange pad is this an old pad or new one as I have the green yellow blue.. Not seen orange..

Thanks

Great finish on the M3 as always :thumb:


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## M.J (Mar 17, 2010)

caledonia said:


> Mike
> In the example I have given I mentioned after the initial set, as you have rightfully pointed out the initial set would have a higher than normal removal rate. Due to the upper most layer being damage by weather conditions, UV damage and the like. This upper layer is essentially a dead layer of paint and very brittle by nature. So the first set will remove this completely and expose a new virgin layer of either paint or clear.
> 
> Unfortunately you cannot gauge how hard the paint or guess the removal rates, as you do not know how the car has lived its life. Was it protected fully. Was it topped up with a good quality LSP and the like.
> ...


no thats fine , it shows the importance of regulary checking what you have removed between sets plus the benifit of a good lsp has to paint condition 
in the long term

thanks
mike


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## SubtleAggressiv (Jul 17, 2010)

What a write up, brilliant transformation of the BM!


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## RandomlySet (Jul 10, 2007)

yet another cracking job Dave and Gordon :thumb:


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## SSB Ad (Jul 25, 2010)

great write up love em always learn something from the detailing king,


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## wes (Jan 20, 2008)

Beautiful work as always! Quick question though, how many man hours?


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## Dave KG (Feb 23, 2006)

wes said:


> Beautiful work as always! Quick question though, how many man hours?


The car arrived around 7, 730am and was picked up at about 9pm - two of us working on it solidly that time with the exception of our lunch hour


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