How many microns do you remove?

I just got my DFT Combo. When I use my orange pad + SIP, I removed about 3-4 microns (This is for an 2007 Audi A3). Which seems way too high. I've tried using different speeds/pressure/passes, but I noticed if I dont use the method that takes out 3-4 microns, quite a few swirls still remain.

How many microns do you guys remove in a typical detail job? I know it varies between manufactures, just an estimate would be nice.

Thanks

 

Paint Removed by Polishing

Using a moderate to light polish; and utilizing a rotary polisher will remove approximately 0.23 Mil (6µ Microns) from the paint surface (they are many variables such as polish/compound and speed / pressure used that may affect the paint removed) There comes a point when you must judge wither removing a scratch will compromise the clear coat and if so you’ll have to ‘live’ with the imperfection. If you have reservations about the amount of paint surface removed or the amount of paint coating remaining the use of a paint thickness gauge (PTG) is arbitrary
The following are the maximum allowable clear coat reductions the major USA car manufacturers will allow: Chrysler – 0.5 mils; Ford – 0.3 mils; GM – 0.5 mils.

 

I'm surprised the others on here don't say how much paint they remove on a detail. A lot take paint readings before ... but what about after? I would think the after results would be just as important as the initial readings to see how much paint you are actually removing. It would also inform others how much paint a polish and pad combo removes on a given paint surface...

 

ya know ive never thought about that. id really like to see that.

so how many microns is a normal cc?

 

Im anxiously awaiting some results here....great thread idea

 

I may work on setting up a database where people can enter the year, make, model and color, microns and location to set up an official central location for PTG readings if people are interested.

 

Thanks people for the help. I would defn like to know what micron levels for each year, make, model and color. Its going to be hard to get a list going though.. haha

Im working on a 2007 Audi A3. most areas its around the 110 mark. Some highs up to 130-140 and some lows down to 80-90s. This is a car that has never been polished. Only done some car washes by dealer during service and never (yes, never) been waxed.... Could mother nature eat away quite some of the CC?

I wont argue that we should try remove as less microns as possible, but I really doubt that taking 0.635 microns will clear up much swirls on most cars... unless that car is really well maintained.

 

ive always wondered what the before and after readings were as well

 

These numbers are offered as a guide only, as there are too many variables to provide any more than an approximation

Removing more that 0.5 Mil (12.5µ Microns) of clear coat will cause premature paint film failure as a point of reference a sheet of copy paper is 3.5Mil (88.9µ Microns) removing more that 0.3 Mil (7. 5µ Microns) of clear coat will cause premature paint film failure a surface scratch that will `catch' your fingernail is approximately 0.04 Mil (1.01 µ Microns) deep will usually require wet sanding and refinishing.
The rate of environmental exposure that negatively effects (clear coat) paint varies widely, but experience shows that 0.005 Mils (127.0 µ Microns) per annum is about average; protective coatings polymer sealants, wax, etc), being renewable are meant to be sacrificial (it is subjected to oxidation, thereby by saving the clear coat)


An extract from “Polishing (Paint Surface Correction) ” one of a series of in-depth © detailing articles by TOGWT ™

 

Great idea!

 

Hmmm, That is a very good question budman3. Now I'm wondering the same thing...:thumb:

 

Well here is the thing about taking reading.

Now I can only speak for my self as this is what I do. I take paint readings with my paint gauges and I document the readings via internal memory within my paint gauges, with the help of software I'm able to down load the readings and store/print them from my computer. Now from time to time I use a method that I saw the UK detailers use. What one of the UK detailer did/does is he uses a red light attached on to a tripod, continuously pointing to the exact same location you'll take paint gauge reading before and after you have polished.

The problem is that when you take paint gauge reading and you don't document exactly where you have taken the before reading and the chances of you taking the after readings at the exact same point as the before is hard to do. So because of this I don't take readings after. Like I said from time to time I do the red light dot test to see how much a polishing combo will remove, specially when I'm dealing with soft clear coat from Honda.

For the most part when you do wet sanding, follow up with a compound then a polish and finish off with a finishing combo you remove between 10 to 15microns. That depends on how much you choose to wet sand, I personally only use 2,000, 3,000 and 4,000 grit. I try to use 3,000 and 4,000 the most but from time to time I'll use 2,000. The reason I choose to use these grits is because I'd rather take my time wet sanding rather then just go extremely aggressive to remove the scratch, I'd rather remove as little as clear coat as possible rather then wasting clear coat and removing too much. That's how you can get in to trouble, some times scratches don't look so deep but the further you chase the less clear coat your leaving behind. Again this is just my opinion.

I hope this helps.

 

Great thoughts Nica.

 

I agree with Nica. Without the laser pointer/ tripod trick the guys at OFFYOURMARKS use, its almost impossible to tell exactly how much clear was removed as clear thickness varies so much. Readings a few inches apart could be different. I routinely remov 1-2 microns during a two stage/ three stage polish that doesn't have a lot of deep RDS. That is with orange/green pads and SIP or Power finish/106FF or 85RD. No compounds are used. If you have to sand to remove a scratch it really doesn't matter what grit you use. You can start with 1500 ,2000 and polish to do it quickly or as Nica said, 2000, 3000, 4000 but the bottom line is you will be removing the same amount ( a lot ) of clear to get a scratch out. I prefer to hit them once with 2000 now and then leave it. Happiness is never having to say you're sorry.

 

noob question: After you fully detail a car (polish, sealant, wax) and have managed to remove 3-5 microns of the CC. after you drive the car a few more times what if there are other swirls and scratches that appear? what can be done now to correct the problem since the CC is already thin?

 

I'm going to assume that your car was in decent condition and you used Menz SIP or equivalent to do your polishing. Even if you followed up with a finishing polish, you may have removed a whopping 1 or 2 microns, maybe. You still have lots of CC to play with. If you don't have a PTG of your own, maybe someone near you does and will measure for you before you polish. What kind of car do you have? Maybe we can help with PTG readings we have found on similar cars.

 

I have a Brilliant Black Pearl (paint color name) 2009 Dodge Charger made from Chrysler as its an LX platform. I have not done any detail work on it yet. I am still a noob and am looking to purchase a PC to start off with sometime this summer. However it'll be a couple months before I touch my charger.

Regardless, the charger is my daily driver and it does have quite a few minor scratches and very few swirls. I do want to get it completely taken care of ie: polshing using SIP followed by some 106FF, and then a sealant and then a nice wax. I know that even after I do all of this my car WILL get minor scratches etc... within a the year. So i was wondering if I do this process lets say 2-3x a year then won't I eventually be getting rid of my CC and damaging my paint within its first couple years?

EDIT: I forgot to mention, I don't have a PTG nor do I know anybody in my area who does...Do body shops usually have them?

LMK,

Thanks!

 

I like the idea of the laser light to ensure the exact place PTG reading. (KISS) all I ever did was to measure 6-inches from a horizontal and vertical panel seam / opening (i.e. 6-inches from the hood seam and one reading 6-inches from the fender seam)

 

Hey sorry to bring back a really old thread, but my question seems to fit in here.

I paid 911fanatic a visit not too long ago and had him measure my CC at random spots around the car, if my memory serves me correctly none of the spots he measured were under 110, some were high around 140-150

My car is only 2 years old, and every year I give it a good claybar+ cut polish + sealant
I use an orange pad with my PC plus Menz power finish.

I dont use too much pressure, generally I let the weight of the PC apply the pressure (if that makes sense)

Roughly how many microns would I be removing? (based on the info given)

EDIT: Forgot to mention, car is a 2008 nissan sentra SER

 

This may be worth posting again-

Using a medium abrasive polish and a rotary polisher will remove approximately 0. 1 Mil (3µ ) Range 0.8 – 1.1 Mil (20 – 28 µ) from the paint surface (typically 4 passes at 1500-1800 RPM) but there are many variables such as the abrasive grade of the polish or compound and speed and pressure used that may affect the paint removed) These numbers should be checked with a paint thickness gauge (PTG) There comes a point when you must judge wither removing a scratch will compromise the clear coat and if so you’ll have to ‘live’ with the imperfection.

A paint thickness reading of 4 Mil < ( 100 µ (Microns) is reasonably safe for polishing. 3 – 3.5 Mil ( 80-90 µ) I wouldn't use anything stronger than > 2000 grit polish, 2.75 – 3.0 Mil (70-80 µ) > 2500 grit polish and under 2.75 Mil (70 µ) use a glaze.

If you have reservations about the amount of paint surface removed or the amount of paint coating remaining the use of a paint thickness gauge (PTG) is arbitrary

Note: 1 µ (micron) is 1/1000th of a millimetre or 0.0393700787 Mil or 0.001 of an inch

• 200µ + can be expected on older cars that have been hand painted or a re-painted vehicle
• 100 – 200µ 4 – 8 mil - normal paint thickness
• 80 – 100 µ - 3 – 4 mils, thin paint
• 80 µ < - less than 3 mil, very thin paint

These numbers are offered as a guide only, as there are too many variables to provide any more than an approximation.