There are few areas in auto detailing that are as misunderstood than that of machine buffers and polishers. Anyone who has researched polishers in the hopes of learning the trade has at one time sat there scratching their head trying to understand the differences between each machine and which one would be the best for the task at hand.
I can’t fault anyone for that given that there are so many different options available that get referred to, often incorrectly, by many different names.
My hope for this guide is to break this information down into easily digestible chunks so that you can make sense of it all and know exactly what tool you should start with for whatever job you’re wanting to tackle.
Table of Contents
- Why Machine Polishers Exist
- Buffers vs Polishers
- Basic Construction of an Automotive Paint Machine Polisher
- Types of Machine Polishers
- Rotary Buffer
- Orbital Polisher
- Types of Rotary Buffers
- Types of Orbital Polisher
- What is the Best Buffer for Beginners?
- What Backing Plate Should I use with my Dual Action Polisher?
- What Pads Should I Use with My Dual Action Polisher?
- What Polish Should I Use with My Dual Action Polisher?
Why Machine Polishers Exist
Traditionally people would work polishes into paint and apply waxes by hand. While this worked reasonably well with old single stage lacquer and urethane paints it’s is much more difficult on today’s very hard and very delicate multi part clear coat finishes.
Working a polish into a clear coat to remove scratches can work but it’s a lot of work. The larger the area you have to polish the more unrealistic working by hand becomes. Some clear coats are so hard that it’s neigh impossible to reach a fully defect free finish by hand.
The solution? Machine polishers. Not only are they more powerful than your hands they are much more efficient. They save us that which is most valuable. Time!
Buffers vs Polishers
In the most simplistic terms, buffing and polishing mean the same thing. It’s the act of working a product such as a polish into a surface to alter the appearance of the surface. If you look up the definition of buff it means to polish. That means buffers and polishers are one in the same as well. They are simply two different names for the same tool.
You’ll see me use both words when describing each machine simply because some people may be more familiar with one term over the other and I want everyone to find this information useful.
Basic Construction of an Automotive Paint Machine Polisher
There are four main parts to a modern polisher. There is the the motor, the spindle, the backing plate, and the pad.
- Variable speed motor that drives the spindle.
- Can be pneumatic (run on compressed air) or electric
- Rotating spindle attached to motor that holds the backing plate.
- Sometimes free spinning and sometimes fixed drive.
Polisher Backing Plate
- Rubber or plastic plate that attaches to spindle and holds the pad.
- Often flexible.
- Sometimes has hook and loop (velcro) on one side to hold polishing pads.
- Holds the polishing compound.
- Can be made of foam, microfiber, wool, or a combination of them all.
Types of Machine Polishers
There are two primary types of buffers and polishers: Rotary and Orbital. These terms mostly refer to how the pad rotates around the motor. With a rotary buffer the spindle and pad rotate together in one direction. It doesn’t vibrate, oscillate, or orbit. With an orbital polisher the spindle and pad move about different axis causing the pad to vibrate, oscillate, or orbit (much like the Earth around the Sun).
Beneath the Orbital type of polisher there are sub types of Fixed Orbital, Dual Action Random Orbital, and Dual Action Forced Rotation. The differences between these types is explained below.
- Most resemble an angle grinder because that is what they evolved from
- Some include a fixed or removable handle to one side or another
- Most USA made rotary buffers will have a 5/8″ diameter 11 threads per inch sized male arbor on the spindle that the backing plate screws onto
- Circular rotation with axis at the center of the spindle
- Rotates in single direction
- Directly driven by motor
- Variable Speed
- Outer diameter of pad spins faster than inside diameter
- Fast removal of moderate to heavy swirls, defects, and sanding marks
- Can be used for spreading wax but not a common practice
- Used with wool, microfiber, and foam pads though wool and foam are the most common
- Larger pads are more aggressive due to increase outer diameter speed
- Pad size doesn’t affect machine performance
- No color standard between pads and types
- Pad friction with paint generates heat
- Heat generated between pad and paint is great at pad edge
- Cutting performance is greater at edge of pad
- Burns, swirls, and holograms are easily created if too much pressure is applied or edge of pad stays in one place too long
- Faster material removal means its easier to waste clearcoat and paint
- Learning to use tool properly takes time
- Chance of damaging paint while learning is high
- Perfecting use of tool takes practice
- Similar appearance to dual action sanders
- Some have handles over the top, out the side, or are simply covered in a grippy rubber
- Most USA made DA style Orbital Polishers use a 5/16″ diameter 24 threads per inch female threaded hole that the backing plate screws into
- Pad and backing plate spin at different axis than the spindle
- Pad and backing plate rotation can be forced or free spinning (or both!)
- Variable speed
- Commonly used for light to moderate defect removal. Advances in pads and compounds have made heavy defect and sanding mark removal possible as well.
- Wax application and removal
- Most commonly used with foam and microfiber pads
- Bonnets can be placed over pads for removing polishes and wax
- Vibratory motion generates heat between pad and backing plate
- Larger pads reduce machine performance leading to less aggressiveness
- No color standard between pad brands and types
- Risk are greatly reduced over rotaries due to pad motion
- Pressure on a free spinning orbital slows pad down so risk from excess pressure and speed is greatly reduced
- Aggressive pads combined with aggressive compounds can leave behind micromaring but it’s very hard to do any real damage or to waste any clear coat
- Burning through paint is highly unlikely, especially on flat surfaces
- Learning to use the tool safely only takes a few minutes
- Chance of damaging paint while learning is low
- Perfecting use of the tool takes much less practice than a rotary
Types of Rotary Buffers
Not much has changed in rotary tools and technology. Almost all rotaries are derivative of angle grinders and look the part. The motor is in the body of the polisher at a right angle to the spindle. There are only a couple varieties that place the motor above the spindle
Regardless of appearance and age they all function the same. The motor turns the pad and backing plate in a perfect circle with the option of variable speeds.
The differences between brands are simply differences in tool weight, minimum and maximum speed, and ergonomics (location and shape of handle and grips).
Any differences in price merely reflect the tools power and reliability.
There are a couple companies that sell adapters to turn power drills and other tools into pseudo rotary buffers. These actually work quite well because of how simple the operation of a rotary is and they are equally as risky to use.
Examples of Rotary Polishers
Types of Orbital Polisher
As stated before, there are three main sub-types of orbital tools. There is the Fixed Orbital, Dual Action Random Orbital, and Dual Action Forced Rotation
Fixed Orbital Polishers
If you’ve ever walked down the automotive cleaning and detailing isle at any big box store you’ve probably seen these on the bottom shelf for $20 or so.
Commonly referred to as “Wax Spreaders,” these orbitals are recognizable by their top mounted motors. Most have almost a bell shape to them. They are sometimes labeled as “Random Orbital Polishers.” They are typically low amperage, low speed tools. The pad on them is large and oscillates around a fixed axis to mimic the motion of hand waxing rather than spinning like most other orbitals and all rotaries.
The pads on these tools aren’t usually removable and instead rely on bonnets that are placed over the pad.
While these tools work great for applying and removing waxes and sealants they aren’t great at compounding and polishing. Their low power, speed, and lack of rotation inhibit their ability to remove anything other than superficial defects. The vibration caused from the oscillating pad is also quite uncomfortable for long periods of use.
If you are trying to perfect the surface and appearance of your paint I suggest you move on to the dual action random orbital polishers.
Examples of Fixed Orbital Polishers:
Dual Action Random Orbital Polisher
Affectionately referred to as DA Polishers, DA Buffers, or Random Orbital Polishers these are the most common machine polishers for compounding and polishing clear coat paints. They are used by both novices, hobbiests, and professionals alike.
Related: Top 12 Best Dual Action Polishers
You can identify a dual action random orbital polisher by their resemblance to DA sanders. The spindle is typically mounted perpendicularly to the motor and is much larger due to the counterweight that is necessary to balance out the action of the polisher.
Why are they called Dual Action?
These polishers are called dual action because the pad spins on an axis that offset from the axis that the spindle spins at.
The pad is also free spinning. This means the pad only spins because of the whipping action of the backing plate. The motor does not drive the pad directly. You can actually stop the pad from spinning while the motor is still turning the spindle. This causes a looping pattern in the motion of the pad relative to the paint.
Safety of the Dual Action
The ability to slow or stop the pad by applying pressure to the tool is what makes these tools so safe. Too much pressure simply stops the pad instead of harming your paint.
To keep the tool spinning and working the polish effectively you are forced to apply just the right amount of pressure making it an easy tool for novices to learn on without dire consequences to any mistakes.
Ergonomics of Dual Action Polishers
Newer models of dual action polishers have been developed with reduced noise, vibration, and weight allowing for more work to be done before tiring you out. Much like the rotary polishers the DA polishers can have top or side mounted handles and grips.
Effectiveness of the Dual Action
Advances in pad and polish technology have made these tools incredibly effective. It’s now possible to buy pads and polishes that start out very aggressive to remove serious defect that then finish down to nearly perfect finishes.
Newer DA polishers have also been developed that have greater power and speed than the original DA Sander derivatives.
DA polishers also have the ability to use many different sizes of backing plates and pads to allow them to be used in tight spaces or over large panels. There are even compact dual action polishers that accept extra small pads for really tight detail work.
Examples of Dual Action Polishers
Long Throw Dual Action Random Orbital Polisher
These polishers are very similar to the traditional DA polishers such as the Porter Cable and Griots GG6. What sets them apart is the offset of the mount point for the backing plate and the center of the spindle is greater. A traditional DA has an offset of about 8mm. A long throw polisher can have up to 21mm of offset. This means the orbit of the pad and the whipping motion generated from it are much larger.
Effectiveness of Long Throw DA Polisher
The long throw provides two things, more distance covered by the pad and more power is delivered to the pad, which means you can accomplish higher levels of correction in less time.
Now you would think that this larger offset and more powerful whipping motion would make for a more unruly tool. Fortunately it does not. Most long throw polishers are actually engineered to run very smooth. The counterweight and motor design in them is much more refined than that of earlier DA tools such as the Porter Cable and GG6.
Short Throw vs Long Throw Dual Action Polisher
The two downsides to a long throw polisher are the size and price. Most long throw polishers are limited to 5″ pads and larger whereas smaller DAs like the PC and GG6 can run smaller backing plates and pads to get into really tight areas. Due to the engineering required to make the long throw smooth and reliable the cost is considerably more as well, running as much as three times as expensive as a Porter Cable or GG6.
Examples of Long Throw DA Polishers
Dual Action Forced Rotation Polisher
Similar in appearance and function to a Dual Action Random Orbital these polishers have a pad that spins on an offset axis from the spindle’s axis. The difference is that the pad on these tools does not spin on it’s own due to the orbiting motion of the spindle. Instead it’s directly driven using a gear set. This means the pad will not stop when pressure is applied.
Benefit of the Forced Rotation
Since the pad does not stop when pressure it applied it’s easier to polish out tight areas and curves that would normally stop a dual action random orbital polisher. This style rotation also allows the use of larger pads without affecting the performance of the machine. The ability to apply more pressure to the pad also allows for more aggressive cutting into the paint to remove defects faster.
Drawbacks of the Forced Rotation
Forced rotation polishers like the Flex can be more tiring to use due to the tendency of the polisher to walk or jump around on the paint while polishing. Since the polisher rotation is forced, when you hit uneven surfaces the polisher tries to “pull” itself around, for lack of a better way to explain it, rather than stopping like a typical DA polisher. Because of this you have to be more assertive in holding and driving the polisher.
Safety of the Forced Rotation
The pattern that the pad moves against the paint is more of a wobbly rotational pattern than a looping pattern or circular pattern.
It’s this pattern that makes the forced rotation safer to use. While the margin for error might not be quite as small as the dual action random orbital polishers it’s still a lot smaller than the rotary polishers.
Advances in dual action random and forced rotation polishers have lead to the development of some polishers that can actually switch between polishing modes giving you the best of both worlds.
Examples of Forced Rotation Orbital Polishers
What is the Best Buffer for Beginners?
My recommendation would be to start with a 6″ Dual Action Random Orbital Polisher. You get plenty of power and ability with almost zero risk to damaging your paint. The 6″ polishers will allow you to run multiple sizes of backing plates and pads to be as versatile as possible.
If budget is of concern the Harbor Freight Chicago Electric 6″ DA Polisher is serviceable.
If you can stretch your budget a little further I would get the Porter Cable 7424XP or Griots Garage G9 DA Polisher. The Griots Garage G9 costing the most but also being the smoothest and quietest operation of the three.
Why not the forced rotation or long throw polishers? Mainly price. They cost considerably more, up to three times more. That’s a lot to ask from someone who may only use the tool a couple times and decide this level of detailing isn’t for them. They also require a bit more skill than the standard DA polishers.
What Backing Plate Should I use with my Dual Action Polisher?
On one hand this is going to be preferential. On the other hand there are some benefits to certain size backing plates and pad with certain size pads.
First, you should typically use a backing plate that is slightly smaller than the pad you’re using to provide a buffer and ensure you never hit the paint with the backing plate. The backing plate should also be larger than the spindle housing so that the tool doesn’t overhang the pad, again risking hitting the paint with the tool.
On a standard Dual Action Random Orbital Polisher the smaller the pad you run the less chance there is of slowing the pad down when pressure is applied. You’ll cover slightly less area but have more control. I personally prefer to use a 5.25″ to 5.5″ pad on my Griots Garage G9 polisher which means I use a 5″ backing plate. The polisher is easier for me to work with using the smaller pads than it was with the 6.5″ pads.
What Pads Should I Use with My Dual Action Polisher?
That’s a whole other subject on its own. See my Ultimate Beginner’s Guide to Buffing Pads to learn more. If you’re short on time, and plan to use one of the 6″ DA buffers such as Porter Cable XP747 or Griots Garage G9 with a 5″ backing plate, then a set of Griot’s Garage Orange Correcting Pads, Black Polishing Pads, and Red Waxing Pads will work great.
What Polish Should I Use with My Dual Action Polisher?
This is another big subject of its own that I have written a guide on at Ultimate Beginner’s Guide to Compounds and Polishes. For now just trust that you can’t go wrong with Meguiars Ultimate Compound and Ultimate Polish. Even as an experienced auto detailer now I still prefer these two over the alternatives (yes even M105 and M205) in most situations. They’re affordable, readily available, cut and polish great, and have a nice long working time so you can really get down to business without worrying about dry time or dusting.