• If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Announcement

Collapse
No announcement yet.

Paint Removal by Polishing - An Example (Rotary)

Collapse
X
Collapse
 
  • Page of 1
  • Filter
  • Time
  • Show
Clear All
new posts
Previous template Next
  • #1

    Paint Removal by Polishing - An Example (Rotary)

    One of the most important factors of polishing, be that by hand or by mahcine, is the amount of paint that you are removing from the car with any given polishing method. In this thread, I am going to outline an example of a car which is being polished and the amount of paint removed by each set of polishes - there's more here than simply how much paint removed and what results it gives, there's also something well worth noting which we will get to at the end

    The car used in this example: A white (faded) Vauxhall Vectra SRi V6:



    The paint was well faded...







    The full detail on this car will be the subject of a writeup in a few days time - I have a visitor from Romania, Alex, who is learning the ropes of detailing with me and this is one of his projects But for now, this car will be sued as an experiment base for this example

    First of all, we measure the paint thickness on a selected spot on the car, round a stone chip that wont polish out we took 10 or so readings of the paint thickness over the same spot and calculated the average thickness before starting to polish.

    The starting thickness: Start Thickness = 119.0um

    First of all, the car was polished using Menzerna PO85RD Final Finish on a Meguiars Finishing pad - very light combination, not expected to achieve much correction or remove much paint. The results of polishing with this combo, by rotary, using the Zenith Point Technique:





    Under the Sun Gun, the colour and some of the gloss restored but still a lot of scratches there...





    Using the strip light we can see the deeper RDS better, and also we see a pitting in the paintwork - this is a road rash, lots of little stone chips which are very deep into the paintwork. We will look at removing these and the thicknesses removed required to do so...



    The thickness after one hit of 85RD: After 85RD = 117.3um
    A removal of: Paint removed = 1.7um

    Now, stepping up to Menzerna PO106FA Final Finish, applied using a meguiars W8006 polishing pad using the Zenith Point Technique and we get the following results under the Sun Gun:





    and under the strip light, where we still see deeper scratches and the pitting...



    The paint thickness after 85RD and 106FA: After 106FA = 116.6um
    A removal of: 106FA Removal = 1.1um

    Stepping up again, to Menzerna PO85RD3.02 Intensive Polish on a polishing pad, applied using the Zenith Point Technique and we get the following results...





    Under the strip light we see the deeper RDS are now largely removed, but the pitting remains strongly...



    Definitely making a difference to the finish though!



    The paint thickness after 85RD, 106FA and 85RD3.02: After 106FA = 116.2um
    A removal of: 85RD3.02 Removal = 0.4um

    With less than 3um of paint removed this far, it was decided it was safe to step up to more aggressive compounding to see if the pitting could be minimised further. So, up to 3M Fast Cut Plus, Meguiars W7006 cutting pad, applied by spreading at 600rpm and working at 2000rpm until residue goes clear and machine starts to drag slightly. Results after one hit of FC+:





    Under the strip light, still see the pitting but its getting better...



    The paint thickness after 85RD, 106FA, 85RD3.02 and FC+: After FC+ (1st) = 114.4um
    A removal of: FC+ Removal = 1.8um

    A second hit of FC+ gives:







    The paint thickness after 85RD, 106FA, 85RD3.02 and 2xFC+: After FC+ (2nd) = 115um
    A removal of: FC+ Removal = -0.6um (paint added - this is measurement error)

    A third hit of FC+:







    The paint thickness after 85RD, 106FA, 85RD3.02 and 3xFC+: After FC+ (3rd) = 113.2um
    A removal of: FC+ Removal = 1.8um

    As the pitting is minimising but still there, we keep going with FC+ - we could get more aggressive with #105 or wool here, but the FC+ on foam allowed for a flexible and controlled removal rate.

    So - after 4th hit of FC+:









    Pitting definitely improving here. Paint readings:

    The paint thickness after 85RD, 106FA, 85RD3.02 and 4xFC+: After FC+ (4th) = 108.4um
    A removal of: FC+ Removal = 4.8um

    Bigger paint removal here.

    5th and final hit of FC+ gives:







    Under the strip light we can see the pitting well and truly deadened if not fully removed (remember, these are pin pricks from stones and grit, so they are deep!):





    What of the paint thicknesses?:

    The paint thickness after 85RD, 106FA, 85RD3.02 and 5xFC+: After FC+ (5th) = 107.1um
    A removal of: FC+ Removal = 1.3um

    The finish was then refined using 106FA on a polishing pad, and this gives the following final finish results - still slight evidence of the pitting, but with notable paint removal now, it is best to leave these marks to allow for future correction on the car at a later date, as this pitting will return with more miles (currently 100k on this car just now).









    The paint thickness after 85RD, 106FA, 85RD3.02 and 5xFC+, 106FA: After 106FA refine = 107.1um
    A removal of: FC+ Removal = 0.0um

    Overall, we have removed a total thickness here:

    Total Paint Removed = 11.9um

    which has been enough to go from this:



    to this...



    So, what has all this told us?

    First of all - you think Vauxhall paint is soft?! Well, 5 hits of FC+ and we are only just over 10um of paint removed, so soft is certainly not something we can level at this finish - its always best never to assume the paint hardness as some cars are just different for a variety of reasons.

    Next, look at the initial removal from 85RD - its more than for IP, and similar to FC+! Now this could be put down to gauge error, but this is a consistent finding I am seeing. It would appear the top layer of the paint is consistently softer (especially on older cars) which is possibly down to UV degredation, softening the upper layers of the paint. In any case, expect initial removal rates to be higher than following removal rates as this example shows.

    On the subject of gauge error, you can see that there is notable gauge error here so you should only use the numbers as a guide, an estimate. Take more readings per average and you will help to reduce the "noise" in your data

    I hope this proves interesting food for thought on paint removal rates when polishing, just as an example on a real car
    "A thing of beauty is a joy for ever: Its loveliness increases; it will never pass into nothingness; .... "
    Tags: None
  • #2
    Re: Paint Removal by Poishing - An Example (Rotary)

    Originally posted by Kickin Griffin View Post
    Using the strip light we can see the deeper RDS better, and also we see a pitting in the paintwork - this is a road rash, lots of little stone chips which are very deep into the paintwork.

    [/img]http://i669.photobucket.com/albums/vv56/DavidMcLean/PaintRemoval/Dsc_0201.jpg[/img]
    Dave, it is very hard for me to distinguish from these pictures and my eyes are aging but from distance this does not look like a road rash to me, but a solvent pop.

    Comment

    • #3
      Re: Paint Removal by Poishing - An Example (Rotary)

      Originally posted by ZoranC View Post
      Dave, it is very hard for me to distinguish from these pictures and my eyes are aging but from distance this does not look like a road rash to me, but a solvent pop.
      I would say that it is road rash on this car, if you look closely (granted easier in the flesh) you can see deeper ones of the same style which are effects of bigger stones as well, and the marks follow a trend of being worse only at the front and leading edges reducing in severity backwards... it could be a solvent effect, but all the evidence points to road rash in this example.
      "A thing of beauty is a joy for ever: Its loveliness increases; it will never pass into nothingness; .... "

      Comment

      • #4
        Re: Paint Removal by Polishing - An Example (Rotary)

        Very interesting readings. I was thinking road rash also.
        quality creates its own demand

        Comment

        • #5
          Re: Paint Removal by Polishing - An Example (Rotary)

          I've read that most paint mfg's recommend you go no more than 8 microns for the life of the paint, so I'd say you were pretty agressive.

          Comment

          • #6
            Re: Paint Removal by Polishing - An Example (Rotary)

            Originally posted by yakky View Post
            I've read that most paint mfg's recommend you go no more than 8 microns for the life of the paint, so I'd say you were pretty agressive.
            It will vary dramatically from paint type to paint type... clearcoats for example are a layer which are designed to erode as they protect underlying colour coat (and give the shine also), while a single-stage like this will require the erosion of the paint if it fades over time. UV protection offered by a clear will vary directly with paint thickness, and the thinner you make it the less protection if offered to the interface layer, and if too thin this can lead to clearcoat peeling over a long period of time. But again, so many variables excist such that putting exact numbers on the process is impossible. Bear in mind also, many show cars are block flatted to remove OP, at the cost of about 20 - 30um, compared to that, this is relatively mild.
            "A thing of beauty is a joy for ever: Its loveliness increases; it will never pass into nothingness; .... "

            Comment

            • #7
              Re: Paint Removal by Poishing - An Example (Rotary)

              Originally posted by Kickin Griffin View Post
              I would say that it is road rash on this car, if you look closely (granted easier in the flesh) you can see deeper ones of the same style which are effects of bigger stones as well, and the marks follow a trend of being worse only at the front and leading edges reducing in severity backwards... it could be a solvent effect, but all the evidence points to road rash in this example.
              Might be, it is just that I am not used to see road rash having smooth edges, especially not around points of impact that exceed certain size. I am used to seeing that when solvent evaporated but did not pop and paint caved in / went inward.

              None the less, I am far from a body shop expert so if one is reading this thread it would be interesting to know what trained eye of a professional sees it as and what are the ways to clearly distinguish the two.

              Comment

              • #8
                Re: Paint Removal by Polishing - An Example (Rotary)

                Thanks for taking the time to write up all this data.Any info here is good.

                All of the compounds you used are unavailable to me,here.But I understood every part okay.

                TOP

                Comment

                • #9
                  Re: Paint Removal by Polishing - An Example (Rotary)

                  Originally posted by Kickin Griffin View Post
                  ...Bear in mind also, many show cars are block flatted to remove OP, at the cost of about 20 - 30um, compared to that, this is relatively mild.
                  Can somoene please enlighten me on this? Never heard this term before...is this the same as wetsanding?

                  I really enjoy reading these write-ups. This is the type of information that can only come with years of hands-on experience. Thanks again for taking the time to document your work and share with MOL.
                  NOTE: Post count does not reflect actual detailing knowledge.

                  Comment

                  • #10
                    Re: Paint Removal by Polishing - An Example (Rotary)

                    Originally posted by ColonelCash View Post
                    Can somoene please enlighten me on this? Never heard this term before...is this the same as wetsanding?

                    I really enjoy reading these write-ups. This is the type of information that can only come with years of hands-on experience. Thanks again for taking the time to document your work and share with MOL.
                    Yes, wet sanding but using papers and a sanding block rather than a machine (such as the G220) and foam sanding disks... the papers allow for better removal of orange peel as they do not flex into and out of the peel on the paintwork and thus allow for a better "flatting".
                    "A thing of beauty is a joy for ever: Its loveliness increases; it will never pass into nothingness; .... "

                    Comment

                    • #11
                      Re: Paint Removal by Polishing - An Example (Rotary)

                      Dave,

                      Another excellent write up. I enjoy the detailed explanations and information you provide with your steps and pictures. It makes for an interesting read.

                      I read on here how the pros like to work on single stage paint now and then. Here is another good example of why. You probably would never be able to pull off this kind of a correction on b/c c/c.

                      Mike
                      Why do we drive on a Parkway, and park on a Driveway

                      George Carlin

                      Comment

                      • #12
                        Re: Paint Removal by Polishing - An Example (Rotary)

                        Nice Write Ups. You are on a how to frenzy lately haha
                        Matt

                        Comment

                        • #13
                          Re: Paint Removal by Polishing - An Example (Rotary)

                          Originally posted by Megafast13 View Post
                          Nice Write Ups. You are on a how to frenzy lately haha
                          I'm experimenting again Its the Physicist in me
                          "A thing of beauty is a joy for ever: Its loveliness increases; it will never pass into nothingness; .... "

                          Comment

                          • #14
                            Re: Paint Removal by Polishing - An Example (Rotary)

                            again thank you...


                            Comment

                            Previous template Next
                            Working...
                            X
                            gtag('config', 'UA-161993-8');