Destructive Polishing - Don't get clearcoats hot! by Mike Phillips

[Mike Phillips]

Destructive Polishing - Don't get clearcoats hot! by Mike Phillips



There are a number of reasons why I write an article, sometimes it's to share a tool. Sometimes it's to share a technique. Sometimes it's because a topic continues to pop-up so instead of typing out an answer (over and over again), I'll simply write an article for the topic and then when the topic comes up, instead of typing out an answer I'll share the link to the article. This is one of those instances.


Also because I predict with the introduction of the Cordless FLEX rotary polisher and the RUPES rotary polisher, (plus the FLEX PE14 a few years ago) there is going to be more interest in buffing using rotary polishers. So because the topic of using rotary polishers has come up and with it low rpm abilities I'm writing this article because it's tied to these to things.


Back when I wrote The Complete Guide to a Show Car Shine, this was an updated version of The Art of Detailing and in this second edition I included a dedicated chapter on the tool the rotary buffer. Now days we're calling it a rotary polisher but same thing, a gear-driven tool that spins a pad in a single direction. Polisher/Buffer, Tomato/Tomato. (hopefully you can figure out the tomato/tomato pronunciation so what I typed just make sense. If you don't know what I'm talking about ask someone.


So here's the deal, when I wrote the chapter on the rotary buffer, like all the chapters and information, I wanted to be sure it is accurate. So when it came to the topic of temperature ranges for how hot is acceptable to get a modern clearcoat paint finish, I checked with people that I respected and are also very smart.


From page 124, middle column.

Temperature to avoid

I asked to respected chemists, both good friends of mine, as well as two experts on paint technology and buffing procedures , for their opinions on what are the upper temperature levels to avoid while machine buffing. Their answers were all in a range from 160 degrees Fahrenheit to 180 degrees Fahrenheit.

There's more info on temperature and rotary buffers in that chapter plus the entire books is cram packed with tons of info so if you want to know more - get the book.


Here's some pictures of the book and that section....










Assuming, and I hate assuming but I do trust both of the chemists and the two industry experts, assuming you're not supposed to get the paint hotter than 180 degrees when using a rotary buffer, it's important to monitor surface temp when buffing. This isn't hard to do just feel the paint and go by what I share in this article,



Fight or Flight Method for Gaging Surface Temperature



This is REALLY IMPORTANT if you're buffing a small section of paint because you can heat the paint and the underlying panel up very quickly. When buffing a 2' x 2' area it's not as much of a problem because while you're buffing one side of this large section the paint you just buffed is cooling down. Not so when doing spot repair - so feel the paint and be careful.


This is also why it's "nice" not mandatory but nice to have a rotary polisher that offers low rpms for buffing. The FLEX PE14 and the cordless version dial down to 400 RPM when using the trigger only and in locked position dial down to 600 RPM. The RUPES Rotary Polisher with it's progressive trigger theoretically can as low as 1 RPM but in reality, my guess is the lowest RPM that you can maintain with your finger on the trigger is around 100 RPM - if you want to try to hold the trigger in a way that the electricity is "just" beginning to flow to the motor. This is not really realistic and you don't want to buff at 1 RPM or even 100 RPM. I typed this because the online detailing world is filled with a handful of anal retentive people that love to argue of minutia.




Here's my review for the corded FLEX PE14

Review: FLEX PE14 Rotary Polisher by Mike Phillips



Here's my review for the cordless FLEX PE14

Battery Time - FLEX Cordless Polishers - Real World Detail by Mike Phillips at Autogeek



Here's my review for the RUPES LHR 19E Rotary Polisher

Review: RUPES BigFoot LHR 19E Rotary Polisher by Mike Phillips at Autogeek



ALL of the above reviews contain a TON of information and pictures to help you decide which rotary polisher is best for you.


Jus be careful and don't get the paint too hot.

[PaulMys]

This is not only a great article(s), but the reason you are the best source of info in this field period, Mike.

Newbies (As I was at one time), really get a sense of what the do's and do not's are. Buying your books helped even more.

Anyone new to AGO should read Mike's articles until they are blue in the face. Then read them again. Then buy the books.

I still read mine just about cover to cover every spring even though I still "think" I have it down by now. Lol

Thanks, Mike.

[WRAPT C5Z06]

I always thought you want to keep the paint within 20-30 degrees of the paints temp right before polishing. Let's say it measures 80 F pre-polishing and you hit 130 F buffing that section, that's a huge increase.........but still in the safe range(160-180 F) as stated above?

[JKDesign]

Destructive Polishing - Don't get clearcoats hot! by Mike Phillips

Polisher/Buffer, Tomato/Tomato. (hopefully you can figure out the tomato/tomato pronunciation so what I typed just make sense.

If you don't know what I'm talking about ask someone.

To quote George and Ira Gershwin:

"Potato, potato; tomato, tomato; let's just call the whole thing off"


- Actor Christopher Walken did a hilarious spoof of this Broadway classic as part of the opening sequence for an episode of Saturday Night Live back in the early 2000's.

[Mike Phillips]

To quote George and Ira Gershwin:

"Potato, potato; tomato, tomato; let's just call the whole thing off"

- Actor Christopher Walken did a hilarious spoof of this Broadway classic as part of the opening sequence for an episode of Saturday Night Live back in the early 2000's.

I remember the Christopher Walken spoof - funny stuff and he's a master of his craft.

Thanks for adding the above.

[Mike Phillips]

I always thought you want to keep the paint within 20-30 degrees of the paints temp right before polishing.

Let's say it measures 80 F pre-polishing and you hit 130 F buffing that section, that's a huge increase.........but still in the safe range(160-180 F) as stated above?

Never heard of this or read an article or watched a video explaining the idea?


I'm a big fan of keeping things simple, not turing something that should be simple into rocket science. When buffing out a car, most people don't have much control of the ambient temperature. Some do, but most don't. So when standing in front of a car no matter where you and the car are at - you're either going to buff it out or your not. So if using a rotary buffer just be careful not to get the paint too hot. This is mostly important when buffing small footprint areas for the reasons I outlined above.


And most of us have both of our hands.... if so, click the link below, look at the pictures, read the info I share and you can avoid any mistakes.


Fight or Flight Method for Gaging Surface Temperature

[Paul A.]

I learned this lesson the hard way when first venturing into rotary world! I burned through once and "wrinkled" once...both on my own car.

I now have an infrared laser thermometer standing by when using my rotary. I haven't had any screw ups since and am super mindful of surface temps.

I think this is the biggest fear for those afraid of rotary polishers but using it properly and with Mike's information I find it the best tool for heavy cutting and faster correction.

I also use mainly wool pads when doing major rotary cutting and find them easier to dissipate heat however still maintain safe movement and speeds.

Spot correcting is mainly done with smaller, foam pads but again, keep it moving and monitor temps.

[LSNAutoDetailing]

Great article Mike! This is another reason I advise people not to "chase scratches." and stick with 6-8 section passes in a 2'x2' area. Once one gets fixated on getting that 2" or 3" scratch out there is no movement of the pad over a larger section, thus heat build up, thus clearcoat burn. Probably switching to an applicator and working it a little bit by hand would be more advantageous.

I also have a laser temp gauge and use it quite often. Here in AZ your panel (even in the garage) can already be at 100 before you start polishing. I got mine from HF and it works great... It's not fancy and it didn't cost a lot, but it's fairly accurate and does the job. And I got it for just such reason.

[Mike Phillips]

I and "wrinkled" once...

Another term for a defect caused by a rotary buffer is,

Twist

If you keep a pad in one place for too long and heat up the clearcoat you can twist the paint. You don't "burn" through it, but you do physically twist it into a circular appearance.


Don't ask me how I know....

[Paul A.]

Yup, that's exactly what I did, Mike...i twisted the paint. I was using a 3" pad on a plastic painted bumper.