Rotary VS Dual Action for Compounding

[WillSports3]

The new blackfire aio can remove heavy sanding marks so I'm just saying, the technology is there to save time and get good results.
I think it comes down to paint preservation. Leave as much paint on the surface as possible.

[jslym777]

You need to remove the same amount of clear coat to make a defect disappear no matter if you use a rotary, forced DA, long throw DA or normal DA.

Exactly my point. So if it is needing heavy compounding and a 2 step process. A rotary first followed by a DA is the most efficient.

[WillSports3]

You need to remove the same amount of clear coat to make a defect disappear no matter if you use a rotary, forced DA, long throw DA or normal DA.

Yes, you are correct. But what I'm saying is because of the speed of a rotary, you will likely level the surfaces to beyond what was needed to correct it.

[Mike Phillips]

Achieving results in less time - Assuming you know how to use both machines professionally and assuming you can use any pad/compound option, it seems as though using a rotary for compounding is still the most efficient way to go. (I am talking about compounding, not finishing.)

For full finish correction then, using a rotary, followed up with a DA for finishing - you yield best results using the least amount of time.

- Please chime in on your thoughts

There's a million ways to skin a cat....

(Sorry PETA - just a cliché)


When I say there's a million ways to skin a cat, what you use depends on what you want to accomplish plus how much time you want to invest.

A few weeks ago I cut a car using a rotary and finished out with an orbital. My PRIMARY goal was to TEST out two new tools so I could write reviews. My secondary goal was to do my best work possible as that's how I roll in the Autogeek Shire as well as wanting to show the owner my appreciation for him trusting me with his old 2-door passenger car.


Here's those write-ups with pictures that never disappear


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

Review: RUPES BIGFOOT MILLE LK 900E by Mike Phillips



Here's another cat I skinned using the FLEX PE14 Rotary Polisher first followed by my buddy Frank using an orbital. The pertinent portion is in post #2 of this thread,

How to wash Ferrari Wheels and Tires


I never was able to get to a "dedicated" write-up for the process used for the paint but I did share the process in post #2


See the text in red



Ferrari finished!

And here's the wheels and tires as well as the completed detail job to this Ferrari.

The paint was machine decontaminated using Nanoskin Autoscrub Pads on Porter Cable 7424XP DA Polishers.

The paint was then machine cut using the Flex PE14 with a wool pad and Uber Compound.

Next the paint was machine polished with the FLEX 3401 with a 5" Hybrid Black Finishing Pad and Wolfgang Finishing Glaze.

After compounding and polishing the paint was machine waxed using Wolfgang Fuzion.












Here's the skinny....


I tried to cut the paint or "correct" the paint using only the orbital but it wasn't working fast enough or effective enough, meaning I was spending too much time and too much energy trying to remove the deepest swirls and scratches with the FLEX 3401. So instead of continuing down that road I simply switched over to a wool pad on a rotary and made fast work of leveling the paint.

Then Frank followed me with the FLEX 3401 and removed the hologram scratches left by the fibers of the wool pad.

Fast - Efficient - Show Car Quality

[jslym777]

Yes, you are correct. But what I'm saying is because of the speed of a rotary, you will likely level the surfaces to beyond what was needed to correct it.

You are assuming that someone is making a mistake with a rotary but not with a DA. Let's take mistake out of the equation by saying the operator is proficient.

[WillSports3]

I am assuming the operator is proficient. I'm just not assuming the operator is perfect. I'm not saying the rotary is not a necessary tool but the rotary really shouldn't be the first thing a detailer goes to, especially on a factory paint job that someone from the dealership has already buzzcut with a rotary.

[dlc95]

A modded 21, 5" plate, xtra cut megs mf pad, m100... Yeah, give me the wool / rotary. I don't want to see bare metal.

[Paul A.]

There are times when I do a few test spots and determine my rotary and wool is needed. For example, I might do 2 test spots with my Flex 3401 and increase the aggression with the second test. If the second test is an improvement but not yet enough it's rotary and wool time. The last time in recent memory was a black Cad Escallade swirled to high heaven. The paint was very hard. I also do not remove any more paint than is necessary to level defects. By my 3rd test spot I have a pretty good idea how deep I need to go...safely.

Yup, I could continue with my Flex and work my butt off and get similar results but time IS a factor and there are those times that a rotary and wool are needed. When I do that I have instantly gone to a 2 step job to correct.

I can't remember the last time I needed more than 2 steps to cut and polish. The equipment and abrasives are that good now. They are so good that I am doing a lot of 1 steppers. Most of my work is done with my Flex 3401...whether 1 step or 2. BUT, when faced with hard paint and needing to cut down faster I always reach for my rotary.

And yes, I know how to use both. It's just that the Flex does almost as good as my rotary especially with today's products. "Almost as good" means I need to go rotary to save time ON SOME JOBS.

Having said all that, I agree that on certain jobs I cut with my rotary and refine with my 3401.

Good discussion btw. I enjoy other's perspectives.

[Joel1979]

Imo Rupes and microfiber/wool beats rotary in terms of cutting power unless you use those 10 inch knitted woolpads. I hardly ever compound with rotary but i sometimes like to finish with it just for fun and change.

[jslym777]

Imo Rupes and microfiber/wool beats rotary in terms of cutting power unless you use those 10 inch knitted woolpads. I hardly ever compound with rotary but i sometimes like to finish with it just for fun and change.

If this is your claim, then is it correct to say that the Rupes possesses the same or more risk factor as that of a rotary since it has better cutting power?