Approx what % of clear removed w/medium polish?

dnadrifter

New member
Hi All,



So let me state of couple things up front before I get to the heart of my question. Thanks to everyone who ends up reading what will probably be a rather long post.



I am new to this and am trying to learn and get any idea from all you experts who have learned this through a lot of years of experience. I have never used a PC or any machine before and am deciding if I should purchase one. I have tried to read quite a bit already , but obviously haven't read everything. I understand that the answer to this question will depend on the polish, the pad, how much pressure, rotary or DA, depth of the clear, softness or hardness of the clear, etc. So I am not looking for an answer of "a medium polish will remove 13%" of the clear coat.



Basically, I am looking for will a medium polish remove 2, 5, 10, 20, 50% etc., as I really don't have a good idea. Another way of putting it, how many times can one realistically safely polish a car to get out medium scratches and swirls. (I don't even know if I know what a medium scratch is, relative to a deep or shallow one)



The reason I ask is the following: I recently got a new to me car (its a 2004 BMW in case folks can provide specific advice depending on how hard BMWs clear is). It is a silver gray metallic and has a few fairly obvious (when you look), what I would consider shallow scratches looked to be caused by someone trying to remove dirt or something with a dirty towel, cloth etc. Although, I have some 1Z Paint Polish that I used by hand with a foam applicator, and it didn't do much to the scratches....so maybe they are deeper than I thought. I would like to get the car looking as good as I can for a semi-daily driver (doesn't need to be perfect), but I really don't want to mess it up.



So hypothetically, lets say I would use Manzerna SIP and an orange pad. (from what I have read, this to me, would seem like medium or light/medium cutting) On AVERAGE....What percent of the clear would be taken off...or how many times could this be done to car without destroying the clear. If folks feel more comfortable giving a range, that is fine to. The reason I chose the above, is because I think that is the most aggressive I might get, even if it didn't get anything else out. I don't see myself using a wool pad or wet sanding.



My guess to the above question (based on what I have read and the thread in the newbie section that uses a paint gauge during different polishing passes) is that probably somewhere in the neighborhood of 1-5% of the clear is removed. Is that even close? It seemed in the test I read, that most of the clear was taken off with the wetsanding and use of a wool pad.



Any opinions and thoughts are most welcome. And thanks for the long read....I just wanted to make sure you understand where I was coming from.
 
every car will have slightly different readings regarding the clear coat thickness as no two vehicles are the same.



How many times this type of procedure can be done will depend on many things:



Polish Choice

Pad Choice

Machine Choice

How much pressure

How many passes for ea. product and pad combo



you should be able to polish your car a decent amount. I wouldn't recommend hitting the car with say Meguiars #105 every month or anything like that . . . . . but if your maintain your vehicle and take your time washing it, you may not need to polish heavy at all and will be able to do it less frequently.
 
As you said, there's soooooo many variables it's impossible to really say anything concrete.



However, you are right that wetsanding and wool pads will remove the most clear usually.



Myself, I'm relatively comfortable polishign my vehicles once a year with 106 and a white pad ......... with good washing technique you should only have to do a light polish once a year imho.



Btw, some polishes out there are just nasty. One of them that comes to mind is Menzerna Power Gloss (gloss, not finish) - that beast just destroys clearcoat.
 
however you can use some stuff frequently for light marring such as Menzerna 106 on maybe a white pad or even a black pad for the occasional marring and light swirls.
 
dnadrifer- For practical purposes the PC is just a "fast hand that doesn't get tired". You might find that even the 1Z PP (fairly mild, as medium polishes go) works better via PC than by hand.



No matter what you use or how you use it, polishing to remove marring means polishing off paint. Heh heh, that gets back to the idea of not marring it in the first place and learning to live with imperfection on a day-to-day basis.



But generally, as long as you don't overdo it you should be able to polish the car enough to keep it looking decent for a long, long time. I've had original paint cars that were polished countless times with no problems.



So if I had to *GUESS* I'd say that sure, Menzena SIP/orange, followed by something milder (to bring up the gloss) should be perfectly safe. I use more aggressive measures than that with zero problems. But of coures, YMMV and you just never know until you do it.



Just don't go crazy trying to get out anything really deep. But don't worry about going over an area a few times making such flaws a lot better.



You can usually do a few mighty serious corrections without getting into the danger zone, and you're not coming across as planning to get all *that* aggressive.



Oh, and Welcome to Autopia!
 
efnfast said:
Myself, I'm relatively comfortable polishign my vehicles once a year with 106 and a white pad ......... with good washing technique you should only have to do a light polish once a year imho.



vtec92civic said:
however you can use some stuff frequently for light marring such as Menzerna 106 on maybe a white pad or even a black pad for the occasional marring and light swirls.



Thanks guys. This helps give me idea of what I can do....even though no is giving me is going out on a limb and giving percentages. :D I appreciate it.



Accumulator said:
Just don't go crazy trying to get out anything really deep. But don't worry about going over an area a few times making such flaws a lot better.



You can usually do a few mighty serious corrections without getting into the danger zone, and you're not coming across as planning to get all *that* aggressive.



Oh, and Welcome to Autopia!



Thanks for the info and your thoughts. Yeah , I am definitely not planning on getting all that aggressive. I like your title practical perfectionist. I guess I realize that I can try to make the car look perfect, but if I use it and want to have a life outside of detailing it....I can settle for really nice, with a few "imperfections".



With that said, I have a 7 yr old black SUV that is in pretty good shape overall, but has never seen a polish....and I am here thinking, wow, I could probably make that thing look pretty good given everything I have learned here already.
 
dnadrifter said:
Yeah , I am definitely not planning on getting all that aggressive.... I guess I realize that I can try to make the car look perfect, but if I use it and want to have a life outside of detailing it....I can settle for really nice, with a few "imperfections".



Go ahead and shoot for perfection, but realize that you'll probably fall short (consider your experiences with the 1Z PP). Get it "very nice" and then just concentrate on keeping it that way (i.e., work on wash technique).



With that said, I have a 7 yr old black SUV that is in pretty good shape overall, but has never seen a polish....and I am here thinking, wow, I could probably make that thing look pretty good given everything I have learned here already.



Yeah, give it a go and see how it turns out. Even using a PC (or a more aggressive, yet still newbie-friendly machine like a Flex 3401 or at least the Griot's 6" polisher) with something pretty aggressive, I bet you'll say "good enough!" looong before you take off an appreciable amount of clear.



Heh heh, before too long you'll be asking how to get more aggressive, just wait and see ;)
 
Accumulator said:
Just don't go crazy trying to get out anything really deep. But don't worry about going over an area a few times making such flaws a lot better.



Definite bump to this - I'll usually go over an area once, and that's it until next time.



Yes, deep RIDs suck, but I'd rather have a few and have dozens of applications before I hit the point of repaint, versus none and only being able to polish ahandful of times.
 
SuperBee364 said:
That's the money maker, right there.



I agree. After reading so much here and other places I can't believe how I have been washing my cars before....just doing all kinds of damage. 7 years worth of washing my black SUV. Ya think it has a couple of swirls and scratches.:cry:



I need to read up more, but I already have my grit guard and special drying towels.
 
RaskyR1 said:
Joe posted this a while ago over on MOL and it should give you a decent idea of what is being removed.



How much paint are you removing. - Car Care Forums: Meguiar's Online



This is actually one of the threads I was referring to in my original post and it was very helpful. It told me a lot about how much wet sanding and aggressive polishing takes off but not as much about medium and light polishing. If I read the post right, the meter didn't change at all for the medium polishing which basically means not a lot was taken off..... But, we know that something was taken off. It is too bad the instrument didn't go out to more decimal places so we get better idea of what was going on. Still very informative though. Thanks!
 
There's also a thread that DaveG did comparing amounts of clear removed, too. At the time, it really raised a few eyebrows, cause the PC ended up removing more clear in some of the tests than the rotary did.
 
I believe it was Todd Helme who did the wetsanding vs PC amount of clear being removed. This was removing deeper defects.



With a PC, orange pad and SIP, you will remove very little clear. In the past I have removed extreme defects with various compounding steps via a rotary/wool and only removed .1 mill of clear. Figure your average clear is in the 2.5-3.5 mill range. Of course this # can vary.
 
gmblack3a said:
I believe it was Todd Helme who did the wetsanding vs PC amount of clear being removed. This was removing deeper defects.



With a PC, orange pad and SIP, you will remove very little clear. In the past I have removed extreme defects with various compounding steps via a rotary/wool and only removed .1 mill of clear. Figure your average clear is in the 2.5-3.5 mill range. Of course this # can vary.



Yup, you're right, Bryan, that was Todd's work.
 
I think the net of it is that you'll be removing very little clear, and probably more the first time than ever again once you've done the first big correction. The Porter Cable is a terrific tool and very safe.



Also, it sounds like you have the perfect practice platform - the 7 year SUV. :)
 
gmblack3a said:
I believe it was Todd Helme who did the wetsanding vs PC amount of clear being removed. This was removing deeper defects.



With a PC, orange pad and SIP, you will remove very little clear. In the past I have removed extreme defects with various compounding steps via a rotary/wool and only removed .1 mill of clear. Figure your average clear is in the 2.5-3.5 mill range. Of course this # can vary.



Atlantic Euro said:
I think the net of it is that you'll be removing very little clear, and probably more the first time than ever again once you've done the first big correction. The Porter Cable is a terrific tool and very safe.



Also, it sounds like you have the perfect practice platform - the 7 year SUV. :)



Thanks for all input guys. This really helps me feel a little better about doing medium polishing. And yeah, the 7 yr SUV will be a good test vehicle. We have an older one, but the 7yr old one is black, and I figure I will really be able to see what I am and am not doing.
 
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