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View Full Version : Amount of Microns in a Mil?



Dave Medvic
01-04-2013, 09:14 AM
Saw someone post on our threads recently that we usually remove about 2 microns when we compound a vehicle. Mike has instructed us that there are about 2 mils of Clearcoat on the average car. If this holds true, then we should be able to go lightly compound to remove swirls at least a few times over the life of a vehicle.
I'm hoping Mr. Megane or our other Chemist types can give some input as this topic of Clearcoat removal seems frequent on the forum.
Feed back please

Mike Phillips
01-04-2013, 09:20 AM
This question came up during the live feed of the 1965 Mustang Fastback GT Wetsanding project...


Page 6 (http://www.autogeekonline.net/forum/pictures-autogeek-s-car-week/58597-1965-mustang-gt-fastback-wetsanding-live-broadcast-6.html)


11 mils is 279.4 microns

I used this site,

Mils to Microns Conversion Calculator (http://www.unitconversion.org/length/mils-to-microns-conversion.html)






1 micron = .00024"




:xyxthumbs:

ken tuep
01-04-2013, 09:21 AM
Google states 25.4 microns in a mil.

Sent from my SAMSUNG-SGH-I777 using AG Online

RMM
01-04-2013, 09:32 AM
Google states 25.4 microns in a mil.

Sent from my SAMSUNG-SGH-I777 using AG Online

:whs:

A mil is a thousandth of an inch.

y8s
01-04-2013, 09:40 AM
This question came up during the live feed of the 1965 Mustang Fastback GT Wetsanding project...


Page 6 (http://www.autogeekonline.net/forum/pictures-autogeek-s-car-week/58597-1965-mustang-gt-fastback-wetsanding-live-broadcast-6.html)






:xyxthumbs:

Mike, I forget what page of your book it's on, but there was some talk of paint thicknesses and mils and / or microns. Do you know the section and have anything to confess?

Matt

FUNX650
01-04-2013, 09:49 AM
Saw someone post on our threads recently that we usually remove about 2 microns when we compound a vehicle. Mike has instructed us that there are about 2 mils of Clearcoat on the average car. If this holds true, then we should be able to go lightly compound to remove swirls at least a few times over the life of a vehicle.
I'm hoping Mr. Megane or our other Chemist types can give some input as this topic of Clearcoat removal seems frequent on the forum.
Feed back please

IMHO...
-First and foremost is:
How much factory-applied CC is actually available, from vehicle to vehicle, for polishing; and:
-Secondly:
How much CC can be removed by it being: "Touched"<<<(M.P.)...
Without compromising its UV protection, its long-term life expectancy, and its warranty.


According to OEM's:
Even if the CC is, say, 2 mils (50.8 microns) "thick" (Good Luck on having that much!!)...
No more than 25&#37; of the CC should ever be removed to avoid any compromising---as mentioned above.

"Saw someone post on our threads recently that we usually remove about 2 microns when we compound a vehicle".
-This comes to mind; and, simply:

'Different strokes for different folks'...

:)

Bob

Dave Medvic
01-04-2013, 11:03 AM
Good stuff guys, with the 25&#37; factor that FUNX725 gave us, That leaves approx. 37 microns to work with (barring the Ceramiclear wildcard that Mercedes throws us).
Overall, we should feel confident enough to make several passes. I "Ultimate Compounded" my 2004 Black Tahoe last year and it turned out great. Recently a carwash scraped their pressure washer against my paint. It took M105 and Polish to mostly correct it, but it made me wary of working a customers car should the same occur to them.

FUNX650
01-04-2013, 12:09 PM
I "Ultimate Compounded" my 2004 Black Tahoe last year and it turned out great. <<< :props:

I very seldom go more "aggressive" in compounding/polishing an entire vehicle's CC paint-film.


Recently a carwash scraped their pressure washer against my paint. It took M105 and Polish to mostly correct it,

I, too, sometimes use "a more aggressive method" than Meg's UC...
But that's usually reserved for 'spot-buffing', as you so referrenced.




but it made me wary of working a customers car should the same occur to them.

IMO...It's best to always explain to; and/or, have a brochure for the Customers:

RE: "The CC-Story"
...The Truth---The Whole Truth...


In regards to:


That leaves approx. 37 microns to work with (barring the Ceramiclear wildcard that Mercedes throws us).

-Assuming starting with 50 microns of CC; and, then:

-Assuming that 13 microns of CC have been removed (over a time period) by various means, including:
Compounding, polishing, washing/drying sessions, environmental/man-made fallout, etc.; Thusly:

-To Me...does not equate to having 37 microns "left to work with"...

-Rather, (again: To me)...It means/represents that there are only 37 microns left!!...


-37 microns left, and to last...

(while protecting the BC/substrates, and providing the gloss/shine we've come to expect from CC-paint)...

For the duration/remainder of the vehicle's life-cycle...
As it surely will encounter: More, and more touching, along the way!!



:)

Bob

RMM
01-06-2013, 02:31 PM
Modern CC paints have (from the metal up) a thickness that ranges usually from 80 (thin – usually Japanese) to 130 microns (most will be around 100-130): of that total figure, the CC will only measure 40-50 microns, at most (for thin paint, it won't be that high).

When you are polishing/compunding and removing CC, you will be removing UV protection, among other things (for Ceramiclear, you will also be removing the hardest layer). So, even if you are conservative, you will be shortening the life of your paint system through a combination of factors and, I suspect, in a more than linear way. That is why when I read that people compund/polish agressively once or twice a year my alarms ring loud and clear – factory CC is a precious and very finite resource...

y8s
01-07-2013, 08:40 AM
Mike, I forget what page of your book it's on, but there was some talk of paint thicknesses and mils and / or microns. Do you know the section and have anything to confess?

Matt

I take it back. I just rechecked the section and I had misread. I thought you said 2.01 mils was one ten thousandth of a mm instead of ".01 mils" was. Maybe the proximity of the solitary "1" to the margin made me miss it.

Sorry Mike!

Matt