How do you know when to stop buffing?

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How do you know when to stop buffing?


One of our forum members, Mitchell aka Buggy Bath asked a question today that I thought was a really good question that others might also want to know the answer.

He posted his question to page 5 of this thread,

The Definitive How-To Article for Removing Swirls, Scratches and Water Spots Using a Porter Cable 7424XP, G110v2 or Griot's Garage Polisher

Below is his question and my answers...


Okay. I also have a question about knowing when I am actually done buffing something. Should it be completely smooth with no imperfections? Or do I use a filler or something to hide them?

Thanks



You know that's actually a really good question and the answer depends upon what your goal is?


100 percent Perfection
If you're aiming for 100% perfection or very close to it, then you need to thoroughly inspect each section you buff after the first correction step and make sure all the defects you want to remove and feel comfortable removing have been removed.

If there are still defects in that section then you need to re-buff that section till you're satisfied with the condition of the paint at this time.

It's okay if there's still haze from the buffing process, but ANY "below surface defects" that you don't want to see after you make your final wipe still remain then you need to continue buffing till they are fully removed during this first correction step.

If you don't remove them during the first correction step then they will still be there after the final wipe.

The way to inspect is like you see me doing here in this article, this is how I normally inspect after wetsanding paint and then after the first compounding step. The sanding marks must be removed after the compounding step because the polishing step are only going to restore gloss and clarity. Polishing will remove some of any defects left after compounding of course, but the major portion of any below surface defects must be removed after what I call "The Major Correction Step" in my first how-to book.


Damp-Sanding Tools, Tips and Techniques by Mike Phillips


Checking my work each step of the way by wiping with Mineral Spirits and using the Brinkmann Swirl Finder Light to insure no sanding marks were missed and no swirls were left behind.

redelcamino_033.jpg



For really low panels, if you hold the light down low and at just the right angle it will shine just right to show the "surface" condition of the paint, this is the area you want to be looking at when inspecting. The part of the light I'm using in these shots is the small lit up area that's is the reflection of the bulb in the paint, not the large blown out area lit up by the light.

redelcamino_034.jpg



redelcamino_035.jpg


Note: You never chemically strip fresh paint using products like IPA or MS. The paint on this El Camino was a custom paint job but when I sanded and buffed it, it was already a few years old, i.e. no longer "fresh" paint as in 30 days or less old.




90% Defect Removal
If you're aiming to remove the majority of the shallow swirls, scratches and other below surface defects but not the deeper RIDS or random, isolated deeper scratches, then you should be accomplishing this using the system you dial-in during the correction step of your Test Spot. After doing the correction and/or the correction and polishing step of your Test Spot, inspect thoroughly that section of paint.

If you're happy with the results from your Test Spot, then theoretically, if you repeat or duplicate the process you didn in your test spot to the rest of the car then you should produce the same results.

For this type of buffing I normally don't inspect each panel after I buff it it I assume and trust in my skills to be doing good work.


Great question, I think I'll turn this question and the answers into an article so this information isn't buried on 5 of this thread where fewer people will find it.


Thank you for asking...


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I usually stop buffing when I see primer appear. Seriously though, great post and informative Mike!
 
My wife loves things that shine too but she likes to wear hers on her hands. I prefer driving my shiny things.

I could buy lots of driveable shiney things for what the wife has on her hand :laughing:
 
very nice article mike, very informative for others. and ive always wondered how people are going to correct the chrome paint some will run into, im guessing they use normal clear coat over it so should not be too big of a deal unless its a tri coat and its tinted clear or something, i haven't read into the process of chrome painting yet.
 
Thanks Mike, I just noticed this. Thanks to this site I am learning a LOT about detailing and especially buffing. I recently purchased a Flex DA polisher from AG and really really like it.

I have a question to add. Lets say I finished my buffing cycle (is this proper terminology?) and there are still some imperfections in the paint. Do I immediately start buffing until satisfaction is reached or do I allow the paint to cool a bit? Also, how warm (temp of paint) is too warm when buffing?

Thanks very much Mike!
 
Thanks Mike, I just noticed this. Thanks to this site I am learning a LOT about detailing and especially buffing. I recently purchased a Flex DA polisher from AG and really really like it.

Very well made machine, an excellent choice.



I have a question to add. Lets say I finished my buffing cycle (is this proper terminology?) and there are still some imperfections in the paint.

Do I immediately start buffing until satisfaction is reached or do I allow the paint to cool a bit? Also, how warm (temp of paint) is too warm when buffing?

Thanks very much Mike!

Gosh, great questions.

I would tend to continue buffing as long as it's a section, (16" to 20" squarish or so), and not an isolated defects. The reason why is because when working an entire section, by the time you stopped buffing, wipe off the residue and inspect the paint any heat being held by the paint and the underlying panel will have dissipated to the paint were it's safe to continue buffing again.

For an isolated defect, especially when using a rotary buffer, you really need to watch the surface temperature. I think I've been told in a perfect world you shouldn't heat clear coat paints over 140 degrees when machine buffing. Now paint can reach that temperature just sitting in the sun but I think the harm comes from the paint being pushed against with some type of pad and abrasive at that temperature, not just sitting un-touched in the sun.

Panel temperature is mostly a concern when using a rotary buffer and any type of foam or fiber cutting pad. DA Polishers like the Porter Cable and the Flex create far less heat to the panel when machine buffing.

I have an article that helps a person to understand how hot is too hot without having to own a temperature gun here,


Fight or Flight Method for Gaging Surface Temperature


HandOnFire03.jpg



Good question!

:xyxthumbs:
 
Mike, yeah I was always so nervous about 'burning through' before that I never got deep enough to get the best results. By doing some reading and watching videos I feel a lot more confident now AND am realizing just how much there is to know about paint correction.

I think the right perspective and a fair amount of experience is what is going to be the best educator for beginning buffers.

Thanks for all your help!

Mitchell
 
By doing some reading and watching videos I feel a lot more confident now AND am realizing just how much there is to know about paint correction.

I think the right perspective and a fair amount of experience is what is going to be the best educator for beginning buffers.

Thanks for all your help!

Mitchell


Head knowledge is good, (reading and watching videos), then taking what you learn out into the garage and practicing build experience and confidence.

A win/win combination.


:xyxthumbs:
 
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