Rotary Technique

[alko]

So I sent Mike P a message in regards to this but haven't heard back from him yet, so I'll post it here...

I haven't seen any discussion on this, but I wanted to know if there was a specific reason why people use different "section passes" techniques with a DA versus a rotary. I know how to make a section pass with a DA (left to right, up and down). But how about a rotary? I've only seen people go left to right with a rotary. Is it not necessary that you follow the same technique with a DA? When I used my Flex PE14-2 I only used the same technique as I've seen others do with a rotary, and that is to go left to right. I've only seen one video where someone was following the DA section pass technique with a rotary. Is it just a matter of preference?

-Alex

 

[Kaleb G.]

I don't have a ton of experience with a rotary but it usually seems like more of a challenge to make the up and down passes. Left to right you can really make the machine do all of the work. Like I said though, I don't have as much experience with them as most people here do.

 

[alko]

hhmm...you know what...I didn't even think about it with the forced rotation.

 

[RoadRageDetail]

Checkerboard pattern is best practice with all machines to ensure uniform working time.

 

[statusdetailing]

I agree. I use the same checkerboard pattern on a rotary and DA.

 

[AutowerxDetailing]

IDK if this is correct technique but I just used a rotary for the first time tonight and found that slightly turning my wrist (on my trigger arm) to the left or right let me steer the machine forwards or backwards and left to right. It was much different from a DA where it just sort of jiggles wherever you want it to go. Once I got the hang of it I was able to do checkerboard section passes just like with my PCXP.

Although, I noticed my left to right movements on the rotary were slightly arced instead of straight across like when using a DA. It just felt more normal to let it curve a little bit instead of fighting to keep it going in perfectly straight lines.

 

[RoadRageDetail]

Although, I noticed my left to right movements on the rotary were slightly arced instead of straight across like when using a DA. It just felt more normal to let it curve a little bit instead of fighting to keep it going in perfectly straight lines.

You know you're comfortable with a rotary when you can lock the trigger and steer by one finger on the end of the handle by the cord.

The arced movement is caused by the forced rotation and its tendency to try and move in a circle. Won't cause you any problems unless it gets out of hand. My old mentor used to tell me "if your arms are tired, try using the buffer, instead of letting the buffer use you."

After a while it made sense

 

[alko]

Thanks for the responses guys...I appreciate it. I felt kinda dumb asking this question, but I realize there are no dumb questions.

 

[Mike PhillipsMike Phillips is verified member.]

So I sent Mike P a message in regards to this but haven't heard back from him yet,

-Alex

I was offline since last Wednesday for some vacation time. I returned to work yesterday and spend most of the day editing YouTube videos and creating threads for them, it's all very time consuming.

On YouTube: Episode 7 - What's in Autogeek's Garage?

On YouTube: Episode 8 - What's in Autogeek's Garage?

On YouTube: Episode 9 - What's in Autogeek's Garage?

On YouTube: Episode 10 - What's in Autogeek's Garage?

On YouTube: Episode 12 - What's in Autogeek's Garage?

I haven't seen any discussion on this, but I wanted to know if there was a specific reason why people use different "section passes" techniques with a DA versus a rotary.

I don't know that they do?

I buff out sections at a time when using a rotary buffer but because of the POWER of a rotary buffer tackle larger sections if the panel is large.

The reason to use overlapping passes in at least two different directions is for an acronym called, UMR, which stands for

Uniform Material Removal

And the reason you want uniform material removal is for,

• Uniform Defect Removal
• Uniform Appearance

I know how to make a section pass with a DA (left to right, up and down). But how about a rotary? I've only seen people go left to right with a rotary. Is it not necessary that you follow the same technique with a DA?

There's now "Laws" that state anyone has to move a buffer over the paint in a specific pattern but just going in one direction for ALL the passes can lead to carving ruts into the paint. On older single stage paints, especially metallics, this would show up as what are called,

Tiger Stripes

When I used my Flex PE14-2 I only used the same technique as I've seen others do with a rotary, and that is to go left to right. I've only seen one video where someone was following the DA section pass technique with a rotary. Is it just a matter of preference?

Yes.

But more important is to do something I call the Yoda Technique and that is to,

Let the panel be your guide


Here's what I wrote in this thread,

Alternating Horizontal/Vertical Section Passes?

Second, because some panels are not large and flat, especially on modern cars which are aerodynamic and for this reason very curved, then you use what I call the Yoda Technique, that is you,


"Let the panel be your guide"

(When you read the above sentence, use your best Yoda impersonation)


So of course, if you're working a long, thin panel then you might best work that panel by only going in one direction and doing your best to overlap your passes.

So sometimes because of the shape of the panel, for example a long thin panel, you can only go in two directions, that is side to side or front to back depending upon how you have to stand to buff the panel.

Therefore you have to let the panel be your guide.



Now follow me on this...

While you should finish your last passes on a panel using a predetermined direction, for the INITIAL cuts or "passes" you want to use some type of multi-directional series of passes to ensure uniform material removal. You can accomplish this going in just a singular direction but it requires more focus and experience.

 

[Mike PhillipsMike Phillips is verified member.]

Here's an example of buffing in only a side to side direction as I was buffing on the top of a rear bumper cover on a Scion... not I only move the rotary buffer back and forth but that's because the panel is thin...


Look for the portion where I'm doing surgical buffing, that is with a 3" foam buffing pad and an extension...

Lake Country Buffing Pads Commercial

[video=youtube_share;VRGul_R5lY0&hd=1"]Lake Country Buffing Pads..." target="_blank">Lake Country Buffing Pads...[/video]​

 

[bigez]

I guess with a rotary, you should move faster accross the paint and speed up your passes??

 

[alko]

I figured you were on vacation, and as I mentioned in the PM I meant to put that in this thread. Anyways, thanks for taking the time to respond. You put into words what I've been thinking about lately with the tiger stripes and UMR. Thanks again Mike!

 

[Mike PhillipsMike Phillips is verified member.]

I figured you were on vacation, and as I mentioned in the PM I meant to put that in this thread. Anyways, thanks for taking the time to respond. You put into words what I've been thinking about lately with the tiger stripes and UMR. Thanks again Mike!

Somewhere I have a picture of Tiger Stripes on a single stage metallic finish, have to search an old hard drive to find it.

Tiger Stripes are the result of carving off, or cutting off too much paint as to abrade the actual metallic flakes embodied in the paint resin and thus altering their appearance.

Usually you'll see a stripe, or length of paint on a panel that is lighter than a stripe or length of paint on both sides of it.


Theoretically, you can cut the paint the same way on a basecoat clearcoat finish but because you're working on a layer of clear paint you won't negatively affect the appearance of the basecoat under it but you're still negatively affecting the clear layer.


UMR is normally the goal for a uniform appearance and you dial in how many passes to make in one section during your Test Spot and then hopefully you can simply duplicate what you did in the test spot to the rest of the car and get the same results.

The goal is always the same, use the least aggressive product to get the job done and thus reach your goal while leaving the most amount of paint on the car to last over the service life of the car, especially if the car is parked outside a lot or all the time and exposed to extreme sun.

 

[richy]

I guess with a rotary, you should move faster accross the paint and speed up your passes??

No. If you're using M105 for example, it responds very well to very slow passes.

Alex, go in whatever direction you want. the panel will dictate what direction you go. You just hold it differently depending on how you want to steer it.

 

[alko]

Aye...Richy!!! Thanks for chiming in. Been watching your video in preparation for an upcoming detail possibly using M105/205. I will atleast practice on my scrap hood I picked up this past weekend.