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Swirl marks


get12

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In that case what did they put the grease on with? Sandpaper?

 

Jokers.

brillo pad it seems!

 

Are you serious they said that? I have not heard anything so stupid in my life!

Well apart from "im pregnant"

 

Yep- the person who I spoke to even put me on hold to confirm the 'grease' excuse with a colleague as she had heard about this last week on another call!

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In that case what did they put the grease on with? Sandpaper?

 

Jokers.

brillo pad it seems!

 

Are you serious they said that? I have not heard anything so stupid in my life!

Well apart from "im pregnant"

 

Yep- the person who I spoke to even put me on hold to confirm the 'grease' excuse with a colleague as she had heard about this last week on another call!

 

This is priceless. I'd call Nissan GB for a quote on the grease story.

 

What I cant believe is that some one has actually admitted fault on this.

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In that case what did they put the grease on with? Sandpaper?

 

Jokers.

brillo pad it seems!

 

Are you serious they said that? I have not heard anything so stupid in my life!

Well apart from "im pregnant"

 

Yep- the person who I spoke to even put me on hold to confirm the 'grease' excuse with a colleague as she had heard about this last week on another call!

 

This is priceless. I'd call Nissan GB for a quote on the grease story.

 

What I cant believe is that some one has actually admitted fault on this.

 

Obviously I dont believe it and I think Nissan use this excuse just to get the car back into a dealer so it can be rectified i.e. they dont want to admit liability that their cars are shipped new to customers with swirl marks on them. All the dealer will do is at the very least use a wax filler on the paint then buff up - so masking rather than rectifying the fault - mind - if the dealer was to do that I d rather they did it that way than try and polish the swirls out - 350z paintwork is notoriously thin - 80 microns and less - that does not give an untrainrd Detailer a lot to work with!!!

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80 microns or less? There's not one piece on my Kuro that was that low. Average readings were around the 100 microns. Still pretty thin though, granted.

 

A give filling sealant will make it look nice but will gradually wear away with washes and everyday use. Paint correction is really the only way to go to truly get rid of those damn ( :angry: ) swirls

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80 microns or less? There's not one piece on my Kuro that was that low. Average readings were around the 100 microns. Still pretty thin though, granted.

 

A give filling sealant will make it look nice but will gradually wear away with washes and everyday use. Paint correction is really the only way to go to truly get rid of those damn ( :angry: ) swirls

 

...I sh*t you not pal...a guy who I have lined up to correct my car was recommended by a friend and is a member of the DetailingWorld forum http://www.detailingworld.co.uk/. He mentioned that he had done work on a Z roadster with paint as thin as 80 microns. Lets put this into perspective shall we peeps - you would expect to see thin paint on a quality sports car - for example the newer Ferrari models with carbon fibre body panels you can actually see the weave of the carbon fibre the paint is that thin! Check the link to the Web site above, on the home page you can see a picture diary of detailing work being carried out on a Veyron - they tested the paint at a reading of 180 microns! I am sure that Nissan are not saving on paint to squeeze an extra couple of mph out of them, I think it is just poor quality paint work and cutting corners. :thumbdown:

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As far as I know the paint standards of Nissan are comparable to other makers , namely Toyota, and other models...

I know this does not resolve the above issue, but i have measured paint thickness and i know these machines are extremely sensitive and can give miss-readings and go out of calibrations very easily...

 

I will accept that potentially you could get close to 100microns, if the worst case thickness occurred for ED coat surfacer base coat (colour) and clear coat, but the potential of getting 4 different process at bottom end of tolerance in one single car I find statistically very difficult to accept

 

but definetely I doubt very much the 80 microns figure...

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As far as I know the paint standards of Nissan are comparable to other makers , namely Toyota, and other models...

I know this does not resolve the above issue, but i have measured paint thickness and i know these machines are extremely sensitive and can give miss-readings and go out of calibrations very easily...

 

I will accept that potentially you could get close to 100microns, if the worst case thickness occurred for ED coat surfacer base coat (colour) and clear coat, but the potential of getting 4 different process at bottom end of tolerance in one single car I find statistically very difficult to accept

 

but definetely I doubt very much the 80 microns figure...

 

Hi there,

 

You know about statistical process control - so do I! I will try and keep this simple for you. You need a 'yard stick' by which you measure everything else, you dont just take a measurement from one sample from a production line, you take a number of samples and run SPC. So, there could very well be 4 measure points on a single car showing 80 microns, but where i think you were trying to go with the argument, but not quite getting there is that you need a number of samples to generate a mean (or yard stick) in which to measure all cars by. So, if we extrapolate from what we have just said - if you took 5 cars, measured four points on all of them, and if four came back with a mean reading of say 140 microns, and the last (mine) came back with a mean reading of 80 microns, then yes my friend, your argument would be valid. :)

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I am not talking about SPC ...

 

As I said I am pretty sure the Z will not have 80 microns paint thickness on the main surfaces,

 

Every dimension on a car has a +/- tolerance from nominal. If you picked the minimum thickness specified by Nissan for all the paint coats applied it will all add to more that 100microns...

 

Now if you want to argue that Nissan build to the lower control limit I will probably agree with you, but if you tell me that Nissan are building cars outside of tolerance, by such a large amount I will continue to be dubious about this fact.

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I am not talking about SPC ...

 

As I said I am pretty sure the Z will not have 80 microns paint thickness on the main surfaces,

 

Every dimension on a car has a +/- tolerance from nominal. If you picked the minimum thickness specified by Nissan for all the paint coats applied it will all add to more that 100microns...

 

Now if you want to argue that Nissan build to the lower control limit I will probably agree with you, but if you tell me that Nissan are building cars outside of tolerance, by such a large amount I will continue to be dubious about this fact.

 

 

...well, at least you have agreed that you need more than one car to decide whether a process is within control limits but yeah I agree with you that not all cars are 80 micron standard.

 

Not wanting to cause an argument here but if we are not talking about SPC what are we talking about?!

 

G

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SPC is to understand where the manufactruing process is in relation to the nominal condition.

 

With SPC you have an upper control limit and a lower control limit ...

 

If the process is below the lower control limit ( for paint thickness in this case) the parts are not to design intent. The part etc... is defective, and as such it would be reworked at the end of the line or the the vehicle scrapped and start again.

 

As far as I know the lower control limit for Nissan would be the sum of the nominal thickness - tolerance ... and this I am pretty sure will be 100microns or greater...I am not exactly sure of the dimensions.

 

So my point is Nissan will not manufacture anything that goes below the lower control limit , and definetely not 20% less than LCL.

 

I am not even considering the fact of measuring "x" amount of cars and finding, finding a mean and deciding if on average the cars are "in process"

 

Will Nissan try to manufacture close to the Lower control limit(but still above on average)? yes, because that will save paint etc... will they manufacture an 80 micron paint system... I don't think so.

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In that case what did they put the grease on with? Sandpaper?

 

Jokers.

brillo pad it seems!

 

Are you serious they said that? I have not heard anything so stupid in my life!

Well apart from "im pregnant"

Its not as daft as it sounds. Cars are coated with cosmoline pre transport to protect paint and metal surfaces. It is meant to be removed by cosmoline remover, but of course if they are'nt carefull then swirl marks would be the result I suppose.

 

http://en.wikipedia.org/wiki/Cosmoline

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SPC is to understand where the manufactruing process is in relation to the nominal condition.

 

With SPC you have an upper control limit and a lower control limit ...

 

If the process is below the lower control limit ( for paint thickness in this case) the parts are not to design intent. The part etc... is defective, and as such it would be reworked at the end of the line or the the vehicle scrapped and start again.

 

As far as I know the lower control limit for Nissan would be the sum of the nominal thickness - tolerance ... and this I am pretty sure will be 100microns or greater...I am not exactly sure of the dimensions.

 

So my point is Nissan will not manufacture anything that goes below the lower control limit , and definetely not 20% less than LCL.

 

I am not even considering the fact of measuring "x" amount of cars and finding, finding a mean and deciding if on average the cars are "in process"

 

Will Nissan try to manufacture close to the Lower control limit(but still above on average)? yes, because that will save paint etc... will they manufacture an 80 micron paint system... I don't think so.

 

 

I see - I bow to your better knowledge on the subject - cheers :thumbs:

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Guest prescience
SPC is to understand where the manufactruing process is in relation to the nominal condition.

 

With SPC you have an upper control limit and a lower control limit ...

 

If the process is below the lower control limit ( for paint thickness in this case) the parts are not to design intent. The part etc... is defective, and as such it would be reworked at the end of the line or the the vehicle scrapped and start again.

 

As far as I know the lower control limit for Nissan would be the sum of the nominal thickness - tolerance ... and this I am pretty sure will be 100microns or greater...I am not exactly sure of the dimensions.

 

So my point is Nissan will not manufacture anything that goes below the lower control limit , and definetely not 20% less than LCL.

 

I am not even considering the fact of measuring "x" amount of cars and finding, finding a mean and deciding if on average the cars are "in process"

 

Will Nissan try to manufacture close to the Lower control limit(but still above on average)? yes, because that will save paint etc... will they manufacture an 80 micron paint system... I don't think so.

 

I'd quite like to understand exactly what you are saying here ..

 

Are you saying

a) there is a proposed process to paint to 100 microns. A car or several cars (samples) is (are) painted and the end result is tested. If it passes, the process is deemed valid and may be applied to paint cars on the production line

or

B) every car is tested after it has been painted to test whether its paint thickness is within tolerance

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There will be a design standard which the factory have to adhere to.

They will then design a process which can achieve the required standards.

The process will be trialled during the development of the vehicle.

The capability assesed and the go ahead given when the processed is tuned to the required spec.

Also not every single one but there will be regular checks, to ensure the process 'within the limits'

I am not sure of the exact paint process in Tochigi Factory but I am pretty sure it will be extremely capable (Japan customers are well known to have much less tolerance for paint defects on cars than Europeans), and they manufacture other high end models in the same factory.

It will be highly robotised, so the consistency from one car to the next will be very good.

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Guest prescience

Thanks :thumbs:

 

The consistency between cars is the key - as you will know this kind of process will give results which follow a normal distribution with say a mean of 100 microns (the average over all cars). The consistency is then the standard deviation with for example, 95% of cars falling within 2 sds.

 

So if the sd was 10 microns, 2.5% of cars would have a thickness of 80 microns or less.

 

[numbers are illustrative, but there will always be a small (but finite) percentage of cars below a given thickness]

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95% is not good enough... they should be operating a minimum 3 sigma process capability (99.73%) ;) , the plant here can achieve it... i don't see why they cannot achieve this in Japan... B)

 

and I am not saying the 100microns is the average...but more the lower limit of production, I do not have factual information but it is "well" informed guess

 

Anyway... as I said, it is my opinion, I would be very dissapointed with Nissan. And just to prove this I will measure my car... I'll let you know honestly...

If it is 80 microns I will sell the car and get myself a Beemer. :p

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Guest prescience

I think you'll be safe on your test ;)

 

My point is that with any normal distribution, 95% fall with 2 sigma and 99.73% within 3 sigma - that's a function of the maths of the ND :)

 

You, I think, are saying that the process will be tested against a laid-down mean and sigma and the test results (for tested vehicles) need to be within 3 sigma of the mean to be satisfactory in terms of Quality Control - that sounds pretty standard to me :)

 

[As you note, the required performance won't be stated in terms of sigma, just as a mean standard and a tolerance either side within which more than 99.73% of cars need to fall when tested (which equates to the same thing)] :thumbs:

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Here's the Paint Thickness that Craig Mudd (muddydetail.co.uk) carried out on my GT4 before his awesome Detail...

 

350PaintThickness.jpg

 

You may not see the numbers clearly but the highest is 184 (presumably a resprayed door) and the lowest 79 on the edge of the bonnet.

 

Averages:

Bonnet - 96.5

Driver's Front Wing - 104

Driver's Door - 163

Driver's Rear Wing - 119

Pass Front Wing - 151.4

Pass Door - 119

Pass Rear Wing - 112.5

Boot - 136.4

 

Not sure what this means but to me it means a proper Paint Correction Detail cannot be carried out too often if it removes 3-5 microns each time.

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[following this item up...]

 

I will be buying a beemer.... :rant:

 

It is possible to get 80microns. My assumptions were very incorrect...

So I retract any defense I made of Nissan and paint manufacturing process...

 

:thumbdown:

 

:thumbs:

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  • 3 weeks later...
...car is going to the dealers' this Saturday for an inspection by the manager - i'll let you know what happens!

 

...went ot dealers - they did not admit liability naturally - got a £50 off next service as a show of good faith - did not expect anything else really, so got on to a pro detailer and here it is! Note the 63 micron reading!

 

http://www.detailingworld.co.uk/forum/showthread.php?t=34557

 

enjoy!

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Nice job :thumbs: did the dealer pay for the detailing ??

 

...yeah right :dry:

 

....they gave me £50 off next service - that did not even cover petrol money getting up to the dealer! :)

 

To be honest I thought I knew the answer before I asked the question... Bloody dealers :blush:

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