# How many passes is too many?



## JunglistJed (Oct 26, 2012)

Hey guys,

I have began work on my 2007 BMW 3 series which has some pretty beat up paintwork. I Started on the boot lid and have done 3 separate passes with a heavy cut compound and orange pad. Each pass would consist of 6x horizontal and 6x vertical passes. The paint has come up lovely apart of some scratches that still persist, they aren't rough to feel and pass the fingernail test but i really don't want to overdo it. I am using menzernas heavy cut compound which has always worked wonders for me so wondering if it just needs some more passes? im using it on an orange pad with a DAS 6 PRO.

Cheers guys!


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## andy__d (Jun 27, 2018)

When the shiny metal shows ,, thats too many passes 

seriously though,
Do you own a Paint Thickness gauge , did you take a set of readings Over the boot lid with it Before you started, and have you taken another set of reading since polishing it ?
if you havent and didnt,, your question is "how long is a piece of string".

has the boot lid been resprayed? has it been polished before ? if so how much clear was removed , is it a single stage paint ? 

without those answers ,, your guessing - stop when the shiny metal appears


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## Andy from Sandy (May 6, 2011)

To answer your question you need to think about what sort of correction are you looking for?

If 100% then the number of passes will be when there is no more defects. To obviously continue after that is just taking more clear coat than is necessary.

As above is there enough clear coat to meet your expectations?


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## chongo (Jun 7, 2014)

JunglistJed said:


> Hey guys,
> 
> I have began work on my 2007 BMW 3 series which has some pretty beat up paintwork. I Started on the boot lid and have done 3 separate passes with a heavy cut compound and orange pad. Each pass would consist of 6x horizontal and 6x vertical passes. The paint has come up lovely apart of some scratches that still persist, they aren't rough to feel and pass the fingernail test but i really don't want to overdo it. I am using menzernas heavy cut compound which has always worked wonders for me so wondering if it just needs some more passes? im using it on an orange pad with a DAS 6 PRO.
> 
> Cheers guys!


I assume you are using FG400:thumb: this compound is a DAT compound, it breaks down as you work through the cutting cycle :buffer: Doing any correction work on paint that you don't know the history of is running the risk of removing to much clear coat, so this is why you should use a PTG just to guide you.

Now if you have removed the defects and are left with the more deep scratches then I would not carry on and move to the next section.

Correction work is to remove defects but also to conserve the clear coat, as you never know, at some stage in the future you may have to correct that same area. If you happy then move on:thumb: but it's not about how many passes but how the compound starts to break down. To many passes can actually cause minor defects in the paint, so maybe shorten your passes a bit and watch your compound as it becomes transparent this is a good indication it's reached its compounding cycle :thumb:


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## Ultra (Feb 25, 2006)

A 100% correction is not always possible or worth chasing, as already mentioned, should you have a minor scratch in that same area in the future you'll not enough clear coat left to play with.


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## [email protected] (Apr 2, 2007)

I take it you're using a DA? Your best bet is to properly prime the pad first, put some polish on the scratches and polish these areas first till you are happy, only polish the scratches. Then when you have removed as much as you can polish the rest of the panel.

Doing this is better than polishing the same large area 3 or 4 times. 

Remember you can only properly check your results if you wipe down with a panel wipe.


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## stangalang (Nov 27, 2009)

They are sets, not passes. A pass is one completed "pass" over your work area, a "set" is the completion of a number of passes. And the amount of each will be dictated by the finish you are trying to achieve and the amount the paint will handle. Neither of which this forum can help you with as only you know whats required, how much paint you have removed and how much is remaining 

Remember, machine polishing is an art, not a science. There are so many minuscule nuances when machining that make an enormous difference to results, no matter how many manufacturers put colours on things and try to standardise it


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## WristyManchego (Sep 9, 2018)

stangalang said:


> They are sets, not passes. A pass is one completed "pass" over your work area, a "set" is the completion of a number of passes. And the amount of each will be dictated by the finish you are trying to achieve and the amount the paint will handle. Neither of which this forum can help you with as only you know whats required, how much paint you have removed and how much is remaining
> 
> Remember, machine polishing is an art, not a science. There are so many minuscule nuances when machining that make an enormous difference to results, no matter how many manufacturers put colours on things and try to standardise it


Jesus, any higher and your brows will be on the top of your head.


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## stangalang (Nov 27, 2009)

WristyManchego said:


> Jesus, any higher and your brows will be on the top of your head.


:lol: or I'm right, and we cant help people without actually being factual.


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## WristyManchego (Sep 9, 2018)

stangalang said:


> :lol: or I'm right, and we cant help people without actually being factual.


Your approach though mate; you've described a tennis match then said no one can help him, and finished with schooling him on the "art" of polishing.

None of that is helpful.


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## stangalang (Nov 27, 2009)

WristyManchego said:


> Your approach though mate; you've described a tennis match then said no one can help him, and finished with schooling him on the "art" of polishing.
> 
> None of that is helpful.


Its ALL helpful to someone who actually wants to improve. A pass is not a set, now he knows that he can both ask more accurate questions getting better answers, and help other users more concisely. Thats a win win
Asking people who aren't working on a car with you how much you can push your luck is dangerous, giving him a number is not helpful, explaining that my number, your number, his number, are all different, means he hopefully wont rely too heavily on arbitrary information and make mistakes he perhaps could otherwise have avoided. 
All usable, helpful information from someone who wants people to avoid needless mistakes. 
Or we can just call things high brow and stuff


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## JunglistJed (Oct 26, 2012)

andy__d said:


> When the shiny metal shows ,, thats too many passes
> 
> seriously though,
> Do you own a Paint Thickness gauge , did you take a set of readings Over the boot lid with it Before you started, and have you taken another set of reading since polishing it ?
> ...


Unfortunately not mate which is why i don't want to overdo things! The car has never been resprayed and has never been polished. Proceed with caution seems like the best bet!



Andy from Sandy said:


> To answer your question you need to think about what sort of correction are you looking for?
> 
> If 100% then the number of passes will be when there is no more defects. To obviously continue after that is just taking more clear coat than is necessary.
> 
> As above is there enough clear coat to meet your expectations?


Unfortunately i don't have a paint depth gauge so id only be estimating, think i should go with the notion rather safe then sorry!



chongo said:


> I assume you are using FG400:thumb: this compound is a DAT compound, it breaks down as you work through the cutting cycle :buffer: Doing any correction work on paint that you don't know the history of is running the risk of removing to much clear coat, so this is why you should use a PTG just to guide you.
> 
> Now if you have removed the defects and are left with the more deep scratches then I would not carry on and move to the next section.
> 
> Correction work is to remove defects but also to conserve the clear coat, as you never know, at some stage in the future you may have to correct that same area. If you happy then move on:thumb: but it's not about how many passes but how the compound starts to break down. To many passes can actually cause minor defects in the paint, so maybe shorten your passes a bit and watch your compound as it becomes transparent this is a good indication it's reached its compounding cycle :thumb:


You would be right mate! haha, you are very right about the reture defect remark actually, never thought of that! only spot im tempted to work harder on is the passenger side where the car has been parked and scraped by another unfortunately.


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## JunglistJed (Oct 26, 2012)

Ultra said:


> A 100% correction is not always possible or worth chasing, as already mentioned, should you have a minor scratch in that same area in the future you'll not enough clear coat left to play with.


Ill certainly listen to this remark mate, im certainly not going to be scratch free for the foreseeable future even as much as id like to be!



[email protected] said:


> I take it you're using a DA? Your best bet is to properly prime the pad first, put some polish on the scratches and polish these areas first till you are happy, only polish the scratches. Then when you have removed as much as you can polish the rest of the panel.
> 
> Doing this is better than polishing the same large area 3 or 4 times.
> 
> Remember you can only properly check your results if you wipe down with a panel wipe.


Correct mate yes, ill actually try this so thankyou! next thought to do it, but there is a spot on the side especially where theres some very concentrated scratching so this should hopefully work a treat  thanks mate



stangalang said:


> They are sets, not passes. A pass is one completed "pass" over your work area, a "set" is the completion of a number of passes. And the amount of each will be dictated by the finish you are trying to achieve and the amount the paint will handle. Neither of which this forum can help you with as only you know whats required, how much paint you have removed and how much is remaining
> 
> Remember, machine polishing is an art, not a science. There are so many minuscule nuances when machining that make an enormous difference to results, no matter how many manufacturers put colours on things and try to standardise it


Ooh i see! I wasn't sure on the terminology at all if im being honest haha, suprised 'passes' is even one! will keep in mind for future questions


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## andy__d (Jun 27, 2018)

Thats how i "deal with" it, err on the side of caution by a lot, 
not having a Paint thickness gauge isnt a issue for me as i also dont have a DA or rotary 
my car is 14 years old, and has 14years worth of swirly paint so hand polishing = stuff that on an estate !
(it also had 14years worth of not looked after insides But im slowly sorting that as good as it can get, things like "recolour the leather" are a step too far same as buy a PTG and DA + bits)


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