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Machine Buffing

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#1 Autopia Expert

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Posted 26 March 2002 - 09:53 PM

by David W. Bynon
<font size="1">Copyright©, 1999-2002, Autopia -- All Rights Reserved</font>

Most professional detailers use buffing machines to polish and buff paint. The reason is time. To do the job properly by hand would be prohibitively expensive. It’s also true that some jobs will get better results with a buffing machine in the hands of a pro.

There are basically two kinds of buffing machines: buffers and orbital polishers. A professional painter’s buffer is nothing more than a body grinder with a polishing pad in place of the grinding disc. _These are high power, variable speed motors that give a professional painter a lot of flexibility. Buffers have a straight drive to the polishing head (i.e., the polishing pad connects directly to the shaft of the motor). Orbital polishers, on the other hand, have much less power, may or may not be variable speed, and have a special drive head that causes the polishing bonnet to run in a variable pattern.

I often get questions like “Who should use a buffer, and why?”, or “What’s better, a polisher or a buffer?”. This is not an easy question, because no matter what I say, there is an opposing and equally valid response.

Buffers are for pros or serious enthusiasts. The opportunity to ruin a paint job with a buffer is too high when a powerful, rotating machine is put in the hands of an unskilled person. Buffers spin at 1700 to 3600 RPM. One small slip and you’ll pop off a molding, burn a hole in your paint, or break off a windshield wiper. I’ve seen each of these mishaps, so I know it can happen. That said, the high-speed buffer is my tool of choice. I put myself in the category of a serious enthusiast, and I have had two minor mishaps in 20 years. For me, the result is worth the small risk.

A good polisher can also deliver great results on all but the worst paint finish. And, for this reason alone, I think most people should invest in a polisher, not a buffer. Polishing machines can be purchased for as little as $50 or as much as $300. The difference in capability is significant. At the low end are low power orbital polishers. These machines are designed for the average car owner who wants an easier way to polish and wax their car. Although they will make the job of polishing and waxing easier, they will not improve the resulting finish of your car. At the high end, you will find multi-purpose detailing machines that polish, buff and scrub carpet and upholstery.

<strong>Buffing & Polishing Pads</strong>
There are two basic pad types: cutting and polishing. A cutting pad is used with a polish or machine cleaning compound to remove oxidation and fine scratches. Cutting pads make quick work, but will leave noticeable swirl marks, especially on dark finishes. After buffing with a cutting pad, it is necessary to make a second pass with a polishing pad and glaze to remove swirl marks and improve luster.

Cutting pads, also called leveling pads, should be wool. There are a lot of synthetic “wool” pads on the market. Don’t touch them! Nothing beats lamb’s wool. Nothing is safer than lamb’s wool.

Polishing pads, often called finishing or waxing pads, are foam rubber. These are the only pads safe to use on a clearcoat finish. Do not use a cutting pad on a clearcoat finish. That said, some expert body shops will use a cutting pad on a clearcoat finish when blending a repair.

<strong>Compounds, Polishes and Glazes</strong>
First rule. Use the least abrasive polish necessary to get the job done. Rule two. No polish can do it all. You may need two, even three products to get the desired results.

Any polish you use with a buffer should state “for machine use” on the instructions. Meguiar’s is very good about this, and I highly recommend their products for machine application by enthusiasts. Many pros use 3M body shop products.

Rubbing compounds should never be used by machine. A rubbing compound is nothing more than sandpaper in a liquid form. If your paint needs compounding, do it by hand. Use a flat pad, such as a kitchen sponge to apply the compound, and buff with a quality 100% cotton terrycloth towel.

Next up from rubbing compounds are cleaners. Paint cleaners, like Meguiar’s Machine Cleaner #1 or Fine Cut Cleaner #2 are for cars with heavy or moderate oxidation. Meguiar’s #1 is about the most aggressive product I would ever consider using with a machine. Both of these products will quickly remove the top layer of dead paint, revealing paint that can be rejuvenated.

Polishes are the paint finish workhorse. Unlike rubbing compounds and cleaners, polish has very little cutting action. A good machine polish will remove small blemishes and restore gloss. A quality polish contains oils to lubricate and hydrate the paint finish. This is where you really get a high gloss finish.

<strong>Preventing Buffer Burns</strong>
Buffing or burning through your car’s paint is perhaps the greatest danger in using a buffer. This risk of paint damage can be largely diminished if you follow a few simple rules.

A paint burn is caused by heat build up on the buffing pad due to friction. Paint burning occurs on the edges of a body panel, not in the middle. I cannot recall seeing a buffer burn though paint in the middle of a hood, door or fender. It is the small surface areas of an edge that builds heat quickly, making a burn possible.

To prevent burns, you need to know how the buffer works. With limited exceptions, buffers rotate clockwise. When using a buffer, lift the left side of the buffer slightly (a half inch or so). Move the buffer in smooth left to right strokes. It is best to focus pad contact on the 12 o'clock to the 4 o'clock quadrant (i.e., the right edge as looking at the top of the buffer). In this way, the buffing pad will always rotate off the edge of a panel.

The reason for lifting the left side of the buffer is to prevent the trailing edge of the buffing pad from driving into a body panel edge. The trailing edge of the pad driving into a body edge creates so much friction it can rapidly burn through the finish. By rolling the right side of the pad off the body panel edge, and lifting the left side, you can significantly reduce the risk of burning.

To further reduce the risk of burning, buff up to edges and body ridges, not on them. When buffing raised peaks or body lines, keep the buffing pad as flat as possible, and slow the buffer speed. Keep the buffing machine moving at all times. If you allow the buffing pad to spin in one spot for more than a few seconds, you’re inviting a disaster. Other tricks include opening the door, trunk or hood slightly. This gives you an edge to roll off of when buffing. Always slow buffer speed when approaching an edge.

The operating speed of your buffer is very important. I highly recommend using slower speeds. Speeds between 1200 and 2000 RPM is sufficient on most modern finishes. The slower speeds can also be used on the older finishes to achieve good results. Just remember, slower speeds create less friction, thereby reducing the chance of burns.

<strong>Buffing Techniques</strong>
Safety first. Wear goggles or work glasses when buffing.

Just like polishing and waxing by hand, buff a section at a time. Always start with the least abrasive polish you can. Buff a section more than once if the results were not satisfactory. If you are not getting the result you desire, try a polish with a little more abrasive. Like I said, it is unlikely that a single polish will do it all. For example, the front of your car gets the most damage.

It may require a medium grit polish to bring the front areas up to par, while the remainder of the car buffs up fine with a mild ppolish. To properly buff, you will need your polish in a squeeze bottle. Squeeze a couple of lines of polish on the panel you want to polish. Don’t use too much, it will just fly off of the pad and go everywhere. Some people prefer to apply a single line of polish around the edge of the buffing pad. It really does not matter which way you go.

Start the buffing slow and use the pad to spread the polish evenly on the panel you’re buffing. Once the polish is distributed, you can begin to increase speed a bit. Work the polish in. Remember to keep the buffer moving.

As the polish begins to “buff out,” and the shine on the paint begins to come up, the polish has done its work. Don’t keep buffing the dry panel. It’s no longer productive. If you’re not happy with the results, add more polish and keep going. Remember to stay off the edges!

When working on top panels, like the hood, trunk or top, you can keep the buffer’s electrical cord from rubbing on your freshly polished paint by draping it over your shoulder.

Be sure to check your buffing pad periodically, as it will become caked with polish. Use a dull screwdriver to clean it. Lay the buffer down, or across the top of your leg, and turn the machine on. Gently press the screwdriver into the pad, starting at the outer edge, and run it in to the center. Do this three or four times until the pad is clean. Don’t use a sharp screwdriver, as it will ruin the pad. Foam pads must be cleaned with water, not a screwdriver.

Polishing with a buffer is messy. You can prevent the splatter mess on your car by using an old sheet. Simply cover the area of the car you’re not working on. Cover the things in your garage you don’t want messy, too. The polish will fling off about six feet or so.

When your finished polishing, your car will have a great shine. If you’re using a cutting pad, it will also be covered in wool fuzz. Simply wipe your car down with a damp terrycloth towel, and your car is ready to wax.

<strong>Waxing with a Buffer</strong>
Some people apply wax with a buffer, while others prefer hand application. I’m a fan of hand application. There does not seem to be any benefit to machine application that I can see, and I believe it uses far too much wax to justify the small time savings. However, a good terrycloth bonnet makes wax removal a cinch.
Apply your carnauba wax by hand with a foam applicator, allowing it to set as recommended by the manufacturer. Use the terry bonnet on your buffer, at low to medium speeds, to buff the wax to a brilliant finish.

<strong>Orbital Polisher Techniques</strong>
All of the tips and techniques mentioned above apply to orbital polishers, too. However, unlike a buffer, the orbital polisher cannot generate enough pad speed to “buff out” a panel like a high speed, direct drive buffer. This does not mean you cannot achieve great results. You can. The technique may be a bit different.

With an orbital polisher, it may be necessary to polish a panel with the machine and use a good terrycloth towel to provide the final buff out. Only the highest quality polishers will generate enough pad rotation (with random motion) to buff out the polish completely. The new Porter Cable Ultimate Detailing Machine is a good example of a random orbit polisher with enough power and speed to buff out polish.

<strong>Hand Polishing after Machine Buffing</strong>
Although a buffer will bring an incredible shine to your paint, nothing beats hand polishing. After buffing my cars by machine, I always follow up with a second pass by hand. I typically buff by machine using Meguiar’s Dual Action Cleaner Polish or Meguiar’s Fine-Cut Cleaner (#2), followed by a hand application of Meguiar’s Hand Polish or Meguiar’s Show Car Glaze (#7). An old cotton tee shirt is my favored hand polishing rag.

<font size="1">Many of the products mentioned in this article are available from <a target="_blank" href="http://properautocare.com">Classic Motoring Accessories</a> and are used at the buyer's own risk.  Autopia is not affiliated with and does not represent Classic Motoring Accessories or the manufacturers of the products mentioned.</font>

#2 ScrampaTeg03


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Posted 11 July 2002 - 11:05 PM

I am going to be buying a PC polisher within the next couple days and have a concern. I know there was only one post made out of the whole entire board but I am now paranoid about burning through the paint on my car. What I would like to know is what areas I should try to avoid with the PC (mirrors, curved edges like the trunk ridge or bumper ridge)? Your help would be greatly appreciated.:up


#3 dboat


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Posted 12 July 2002 - 04:03 AM

I had seen where some QD their car after they wash, then after the polish and then once more after the wax.. is there a real benefit to this method? I have tried it and the truck looks great.. but I would appreciate your thoughts on this though

#4 Black99miata


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Posted 12 July 2002 - 04:41 AM


There is little potential for burning through the paint with a PC. As David states in his write-up, the random orbital nature of the PC does not produce the speed or the consistent direction to cause much worry. I have used the PC on all areas of the car with good results. Relax. Enjoy. You will love it!


#5 afinerdetail


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Posted 14 July 2002 - 11:30 AM

Where can I get 'hands-on' training on how to use a rotary buffer. Where could I purchase a new or refurbished one?

#6 dboat


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Posted 14 July 2002 - 04:54 PM

You can get a new one from Lowes or CoastalTools.com.. dont know about refurb but look for a Porter Cable repair center in your area and they may have them. If you get Davids book, I highly recommend it, there are links to videos.. also, you can go to the Meguiars site and they have video there as well on how to use it..
Since you really cant mess it up too bad, the next step is to get one and use it.. thats what I did and I love it... but do get Davids book.. best bang for the buck I have got in a long time... next best thing is my Ford Lightning..

#7 laynlow


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Posted 14 July 2002 - 06:01 PM


Awesome article. I appreciate it very much. I am thinking of purchasing the DeWalt rotary that ShowroomL recommended, and your tips are invaluable. I only wish some of the rotary pros on this board were in Tulsa! I could use a teacher for a rotary! :xyxthumbs

#8 afinerdetail


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Posted 14 July 2002 - 07:16 PM

What brand name rotary polisher should I select? How much should I pay for one?

#9 JasonC8301


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Posted 14 July 2002 - 07:22 PM

www.autoint.com offers the PrepExcellence class which includes rotary usage and on-hand training. It is located in Cinci Ohio.

If you shopa round and search older threads, you can get a rotary for around $200 or so. The favored models are the DeWalt DW849 and Makita 9227C. Then add in pads and such, you'll get up to around $250 or so.

I have been had it, lol...

#10 RX-8


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Posted 08 August 2002 - 04:50 PM

Great article DavidB! :bow :bow :bow
-- Drive it like you stole it! --
2006 Mazda Miata (Galaxy Grey)
2004 Mazda RX-8 (Winning Blue)

#11 FinishingTouch


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Posted 18 April 2003 - 11:02 AM

I've been practicing power buffing on body panels that a local body shop threw out. So far, so good. My question is, what do you do when dealing with cars with pinstripes? Doesn't buffing remove this or do you just avoid them altogether? I've been using Schlegel foam pads. I like them very well. Then, on edges, do you recommend using low tack tape to cover the edges? I read that you should lift one side of the pad a little, but doesn't that cause swirl marks? I would think the tape would work ok, just would take a little more prep time.

#12 Autopia Expert

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Posted 19 April 2003 - 05:22 AM

If you're using a fine foam pad and a finishing polish, you can go over the pinstripe lightly. If you're compounding, then take the time to mask off the pinstripes. If the pinstrips are hand painted, don't use a machine on them at all.


#13 indy


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Posted 12 June 2003 - 01:19 PM

Hello all,

I'm new to the forum, but have always loved keeping stuff shiny (cars, trucks, boats, bikes...). I've always polished by hand until reading more here about the truely awesome results achievable with a powered polisher. I went out on my lunch hour a picked up a Porter Cable Model 7336SP combination sander/polisher. It is a random orbit polisher with variable speeds from 2600-6000 opm. Any thoughts or tips on the use of this unit other than what David has already meantioned above?

Thanks for your input.

#14 Black99miata


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Posted 12 June 2003 - 02:19 PM

Hi Indy.... and welcome to the forum. The polisher is the tool of choice for most on this forum. Very difficult to screw up and gets all but the worst finishes looking like new (or better). If you use the search feature of the forum, or get one of David's excellent writings on the subject, you will find more information than you would ever have time to read about techniques and tips for using the PC. Try these places out!

Good luck,


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