DA vs. Rotary

danponjican

danponjican

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Can someone give me a breif synopsis on the pros and cons, advantages and disadvantages of a rotary (Makita 9227CY Polisher) vs. a dual action (i.e. PC 7424). As far as I can tell, everyone is saying that there is a danger in a orbital polisher in that it can heat up quicker and cause damage to the finish. Is this because they are higher speeds and/or the single action rotation vs. the dual action orbits? What are the advantages of a rotary over a DA? It sure seems like the pros use rotary units like the Makita. Is it mainly in the experience in what pressure to use and what motion/speed to move it along the surface?

Thanks!
 
the roatary in experienced hands is better in every way...but experience is a BIG factor....the DA polishers are much safer on paint but take much longer to get the same results...i personally use a DA most of the time as I am just more comfortable using it...my rotary pretty much sits on the shelf and only comes out when i meet a heavily oxidized car and i just use it in the bad spots and then switch to my DA. The danger in rotary polishers is that sitting in just one spot it build up heat really quickly and the foam pad you are using quickly goes from polishing to sanding in about 2-4 seconds depending on the pad/speed...

the one thing i will say is that on flat panels of the car the roatary is very easy to use...just when you start turning coners and doing very wavy fenders and edges i get a little leary that i might be hurting something...so hoods and trunks i find easy and safe that i am keeping the roatary moving...everywhere else...not so much....
 
Dual Action --- a very safe machine that transfer very little heat from pad to surface. Because it rotates off axis it is less likely to burn paint. Can be used for minor to medium corrections with great results from novice to professional. Speed is your friend here !

Rotary --- this machine transfers ALOT of heat and speed directly to the surface. Needed for major repairs, and can be used for all updates to paint. Best used via professional as spinning in circle and can literally burn thru light paint/cleared areas rather quickly. Speed is NOT your friend here.
 
How much time does using a rotary cut of a normal d/a detail, I've been thinking of learning to use the rotary, but not really if its worth it, but after taking 4 to 8 hrs with a d/a, depending on size and paint condition, a rotary sounds nice. Also, I've always wondered why pads for a rotary are so big, is it possible to use 6" d/a pads, or is it better to stick with the larger ones.
 
As mentioned, the rotary creates a lot of heat, which allows it to cut paint so much faster than a DA, as well as ruin it if not used properly. It spins on a single axis which makes the pad move very fast and creates heat which is what will burn the paint. The DA polisher just moves around the axis simulating the motion of your hand when polishing by hand. It also spins like a rotary, but it is a free spin, so enough pressure will stop it from spinning. These two actions keep it from generating the kind of heat a rotary does.
 
many people say they can polish a car via rotary in an hour or so instead of the full day it takes with a PC. say you spend 5 minutes working a panel with a PC, its about 30seconds to a minute with a rotary.
 
Depending how things go for my business in the first couple months, I'm going to order a Metabo. I'll use practice with it for months before I switch to it full time.

Even then, I'll only use a rotary for diffucult cars, hard CC, and large vehicles.
 
Kelso said:
many people say they can polish a car via rotary in an hour or so instead of the full day it takes with a PC. say you spend 5 minutes working a panel with a PC, its about 30seconds to a minute with a rotary.
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30seconds :eek: okay so would a person be able to physically see the polish break down? I mean how do you know when to stop? With the PC you can simply time it 5 to 6 min...but with a rotary how do you know?

As you can tell I'm not a rotary experienced person....:D
 
I think if you are trying to cut time the Rotary is the clear winner. I was able to get great results with just a DA Porter Cable but it did take a long time.
 
danponjican said:
I am a total beginner but I think I am going to buy a rotary and experiment. I have an extra fender (take off from my mustang that has a small dent on it) that I can use to test the rotary.

Harbor Freight has a rotary for $30 that would make a nice tool to learn with:

Harbor Freight Tools - Quality Tools at the Lowest Prices
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Not a bad machine...one of my very first........
if you use the edge 2k wave pads?? a lot of the heat will disapate, but you still have to be careful............;)
 
if you are going to go rotary...just buy the best...the makita/dewalt/hitachi are all great models...dont bother putting money into a "pratice" rotary...just put the 30 dollars towards the one you are going to want anyway...you can practice with a top end rotary...
 
Grimm said:
As mentioned, the rotary creates a lot of heat, which allows it to cut paint so much faster than a DA, as well as ruin it if not used properly. It spins on a single axis which makes the pad move very fast and creates heat which is what will burn the paint. The DA polisher just moves around the axis simulating the motion of your hand when polishing by hand. It also spins like a rotary, but it is a free spin, so enough pressure will stop it from spinning. These two actions keep it from generating the kind of heat a rotary does.
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The heat from a rotary can be diminished with the EDGE 2K WAVE PADS

The Edge 2000 Wave 8 inch Foam Pads
.
 
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Dieseldan said:
how is the quality of that rotary?
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VERY GOOD........ I USE IT AS BACK UP AND HAVE IT NOW OVER A YEAR.NO PROBLEMS
 
I keep thinking I'd like to get a rotary once I've fully mastered the PC, but I just don't know if I can bring myself to do it. The rotary is so appealing because it cuts down the time so much. but at the same time, it's so easy to burn through paint. I'm not really worried too much about burning through paint, but I keep my cars several years and I'm just afraid that if I'm polishing them with a rotary I'll be going through the clear in no time.
 
Grimm said:
I keep thinking I'd like to get a rotary once I've fully mastered the PC, but I just don't know if I can bring myself to do it. The rotary is so appealing because it cuts down the time so much. but at the same time, it's so easy to burn through paint. I'm not really worried too much about burning through paint, but I keep my cars several years and I'm just afraid that if I'm polishing them with a rotary I'll be going through the clear in no time.
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I know what your saying......i agree.....but if your careful and use light polishes , sealer's or/and wax's with the least aggressive pads you'll be fine.....

also start off with a not so expensive rotary, unless your in the business and have to use the rotary everyday....then a expensive one is inperative...

you can always still use the P.C. as a change
 
For those who have learned the rotary, how long did it take you to confident with it, also, does anyone know any links to rotary how to videos?
 
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