For nearly 12 years the Porter Cable 7424 was the only decent dual-action car polisher available. In fact, it was the first true pro-consumer car polisher available. That all changed in 2006 when Meguiar’s introduced their G110 polisher.
Today, there are several excellent options for car enthusiasts, including the new Porter Cable 7424XP and the Griot’s Garage 6″ Random Orbit Polisher. Additionally, there is a new class of dual-action car polisher that uses a forced drive system, including the Flex XC 3401 VRG. These professional grade machines will be covered in another guide.
The purpose of this buyer’s guide is to help you choose the best electric car polisher for your needs. This article focuses on the three models listed above because they work and they are safe.
As a seller and user of these products for many years, I have experience testing dozens of polishers and hundreds of polisher, polishing pad and car polish variations. I know what works and what does not. These car buffers work and they are very safe.
You might find it interesting to know that the Porter Cable 7424 (and now the XP model, as well) is not really a car polisher. It’s a 6″ orbital sander!
Somewhere along the line furniture makers started using the sander to put the final finish on tables and other fine furniture. One thing led to another and people started using it on cars.
Why did the Porter Cable 7424 car polisher become so popular within the car enthusiast hobby? Let’s explore the inner workings of a dual-action car polisher and find out.
Please note that all of the car polishers discussed in this guide (Porter Cable, Meguiar’s and Griot’s Garage) work the same way. In fact, they are so compatible that all of the polishing and tool accessories are interchangeable. Any mention of speed settings applies to all three machines, as well.
A dual-action car polisher (often called “random orbit” or “orbital”) is a machine that operates by orbiting the polishing pad around a center spindle while the pad freely spins on its own axis. A counterweight on the opposite side of the center spindle dampens vibration for smooth operation.
The tool head action, often called orbital, prevents the creation of holograms (symmetrical buffing marks), paint burns and other forms of paint damage often associated with high-speed buffing machines. When used with proper care, the dual-action polisher design virtually eliminates the possibility of paint damage.
The polishing action of a dual-action polisher closely mimics that of circular hand polishing. Imagine being able to make 2,500 to 6,000 tight hand circles in a single minute and you’ll have a pretty good idea of how these dual-action polishers do their job. They work just like your hand, only at super-human speed!
Some people have defined a dual-action polisher’s tool action as “jiggling”, but this is not the case. The head freely rotates on a bearing and orbits around the center-line drive shaft. Rotation is a free-wheeling action of the backing plate spindle caused by the orbiting head. This “dual-action” is where the Porter Cable 7424 gets its “DA” nickname.
If you have previously owned a random-orbit car polisher that made a lot of racket, but did little else for your car’s finish, you will appreciate the 7424 as a professional grade machine. Most consumer car polishers don’t have enough power, have a very small orbit (often less than 1/4 inch), and have limited accessories. The Porter Cable 7424 was the first machine to shatter these limitations.
What do I mean by “consumer car polisher?” If you have visited an auto parts store in recent years, I’m sure you’re probably seen the kind of car polisher I’m talking about. They are two handed machines with the motor situated over the pad. Typically the pad is quite large (8″ to 10″), and they carry names like “Wax Master”.
These machines are really electric car waxing machines, not polisher. In my experience, they have more buzz than bite. When it comes to doing any serious work, like removing swirl marks and scratches, they just can’t get the job done.
Even with the able competitors, the Porter Cable 7424XP is still the most popular polisher available. The reason is quality and selection. You’ll find dozens of different prepackaged kits and bundles.
Dual Action Car Polisher Features
The original Porter Cable 7424 was fitted with a pretty powerful motor for its size (3.7 amps). However, as both professionals and consumers started demanding more paint correction capabilities from their dual-action polishers, the motor sizes have increased.
Meguiar’s was the first to introduce a more powerful product with their original G110 polisher. Now all three manufacturers offer machines with 4+ AMP motors. More power is not always better, as it also introduces more noise and more vibration.
These machines function at 2,500 to 6,000 operations per minutes (OPM), controllable by a thumb wheel on the rear end of the machine. The OPM measurement is used instead of revolutions per minute (RPM) to distinguish the difference between orbits and center shaft revolutions.
At 6,000 OPM, these car polishers are doing a lot of work!
Industry Standard Car Polisher Attachments
One of the features that made the Porter Cable 7424 a defacto industry was it’s use of a 5/16-24 spindle for attachments. As a result, a lot of different attachments fit the Porter Cable, making it more versatile. For example, Velcro backing plates in many different sizes, and brushes (for scrubbing carpet), are available with a 5/16-24 fitment.
Car Polisher Ergonomics
All three brands have made significant improvements in ergonomic design, but the Porter Cable 7424XP is the only unit that I feel is vastly improved. All three units are now more slim and trim, but only Porter Cable figured out that the speed dial need to be on the top side of the unit, not the end. The ability to see the speed dial is a very convenient feature.
Also, Porter Cable invented and patented the original oscillating head mechanism with a replaceable counterbalance weight. All others are adaptations of the Porter Cable design that do not approach its strength or versatility.
Car Polisher Size & Weight
In pictures, the Porter Cable 7424 and other dual-action car polishers look larger than they actually are. The machines from Meguiar’s Griot’s Garage and Porter Cable all measure about 10 inches in length and weigh in at about 6 pounds with a backing plate and pad attached.
Unlike a professional rotary polisher, which can weigh in at almost twice the weight, the pro-consumer dual-action polishers are not difficult to handle.
Car Polisher Handle Variations
One of the big differences between the three machines is their handle. Both Meguiar’s and Griot’s Garage have chosen a “D” style handle that puts your hand over the top of the machine head. Porter Cable uses a reversible side handle. Most people I know opt to use no handle at all, as these machines work very well when you grip the top of the machine directly.
Hook & Loop Backing Plates & Foam Polishing Pads
The original Porter Cable 7424 car polisher came equipped with a single white foam polishing pad that is permanently fixed to a 5” baking plate (Porter Cable calls them back-up pads). The standard foam pad was fine for light duty polishing and waxing, but not much else. As a result, a new industry was born.
Today, you can easily find Velco backing plates ranging in size from 3″ to 6″ that will fit all of these dual action car polishers. However, a word of caution. All of these machines are sensitive to backing plate weight. When you deviate outside of the manufacturer’s weight parameters, you may experience higher than normal vibration.
The ideal Velcro backing plate size for all of these machines — for primary use — is 4.25″ to 5.25″. The size backing plate you use is predicated by the polishing pad size. In all cases, you should use a backing plate with a diameter .5″ smaller than the polishing pad. This offers sufficient protection to avoid damaging trim, mirrors and paintwork when polishing in tight areas.
In addition to multiple Velcro backing plate options, you have a virtual cornucopia of foam polishing pads from which to choose. In fact, it can be quite overwhelming and confusing.
If you are just getting started, I highly recommend following the advise of the your chosen polish maker. The reason is that the polish and polishing pad work together to get the job done. When you try to mix and match without experience, you may not experience the results you are expecting.
One of the biggest mistakes I see people make is choosing a foam polish pad by its color. There are no color standards for foam pads, so don’t make this mistake. In fact, many foams with different colors are identical. Other foams that look the same and feel the same may have completely different polishing characteristics.
Car Polisher Features Side-By-Side
Porter Cable 7424XP
Direct Drive Eccentric “Dual-Action” w/ Counterbalance
4.5 AMP, 110 VOLT
4.5 AMP, 110 or 220V
7 AMP, 110V
Velcro Backing Plate
YES (5.25″, flexible)
YES (5.25″, flexible)
Foam Polishing Pad
YES (fixed backing plate)
Power Cord Length
YES (canvas bag)
5 Yr, Parts/Service
Manufacturers Suggested List Price
If you look at the numbers, the Griot’s Garage polisher should blow the others away, but numbers are deceiving. First, I find no evidence that the Griot’s Garage polisher has a 7 AMP (850 watt) motor). I’m not sure how they measured it, but my meter rated it at 4.9 AMPs (full load), and I attribute some of the current draw to be soaked up by the cord and the speed control. In actual use, all three units are very similar in the amount of power they provide.
Price is also an illusion. The Griot’s Garage price is never publicly discounted, whereas the Porter Cable and Meguiar’s units are never sold at their MSRP. The Meguiar’s G110v2, for example, is frequently discounted to $149.95, and the Porter Cable even lower. The other areas that make up the price differences include the backing plate (the Meguiar’s W68DA backing plate is the best in the business and retails for $35), carrying case, and warranty.
The Porter Cable 7424XP is now backed by the best warranty in the business: 5 full years. The reliability of Porter Cable tools is, without question, the very best. Meguiar’s had reliability issues with their first generation G110, but seem to have them solved with the new G110v2 polisher.
They have a no hassle replacement warranty, and their customer service staff are very knowledgeable and helpful. There have also been some reliability related issues with the new Griot’s Garage polisher, although nothing serious.
The new Meguiar’s G110v2 has one feature that sets it apart from the crowd. Internally Meguiar’s calls it “cruise control,” which seem very confusing. It’s an internal feedback circuit that measures speed loss due to increased load from down force placed on the machine. Almost instantaneously, the machine responds with more torque. The result is the best random action polishing of the crowd.
Getting the Best Car Polisher Price
In almost all cases, you will find your best prices online. I have occasionally seen the Porter Cable 7424XP on sale at Home Depot and Lowe’s in the $120 range, but then you still need to shop for a backing plate and pads elsewhere. The Griot’s Garage unit is rarely ever on sale and Meguiar’s seems to be constantly out of stock.
In general, pre-packaged kits and bundles offer the best overall deal. The best kits include polisher, foam pads, and polishes. Some offer additional bonuses, including towels, detail sprays, etc.
In How-To Use a Dual-Action Car Polisher you will find everything you need to know to use a dual action polisher with shining success.