# Upgrading DA



## Bod42 (Jun 4, 2009)

At present I have the DAS-6 Pro which is a very good machine but I'm looking to take the next step up with regarding to a DA polisher.

A lot has been mentioned this year about the FLEX XC 3401 and the Rupes Random Orbital Polisher.

What are the Pro's and Con's of each?


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## Steampunk (Aug 11, 2011)

Here are some good links to check out (Sorry they're on Autopia .):

http://www.autopia.org/forum/machine-polishing-sanding/142973-rupes-lhr-21es-random-orbital-polisher-features-benefits.html

A good analysis of the Rupes by Kevin Brown

http://www.autopiaforums.com/forums/paint-correction-gloss-enhancement/37144-surbuf-mf-pads-flex-3401-a-3.html

Read post #40 by Todd Helme; it's very good at explaining machine action.

Based upon my experience with using Kevin Brown's techniques, and reading A LOT about DA correction theory, I would lean towards the Rupes. My only concern is that its massive stroke (Even on the 15mm machine.) can be something of a double-edged sword, making it a very efficient correction tool, but also making it more difficult to handle in tight spots (Or oddly curved panels.). On modern cars it really shouldn't be an issue, as these situations have been largely eliminated by current styling logic, and mass-production.

Ultimately, the decision is yours, and you can interpret the information as you will. Both are very good correction machines, and despite the Flex's fixed orbital pattern, it is still a well engineered tool that shouldn't disappoint. Both will make quicker work of defects than your DAS-6.

Hopefully this helps...

Steampunk


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## Bod42 (Jun 4, 2009)

Thanks Steampunk I will check them out. I have read up on Kevin Browns Method but never found a summary of exactly what he does compared with the zenith technique that is outlined clearly. What does he do differently in laymans terms


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## Steampunk (Aug 11, 2011)

Bod42 said:


> Thanks Steampunk I will check them out. I have read up on Kevin Browns Method but never found a summary of exactly what he does compared with the zenith technique that is outlined clearly. What does he do differently in laymans terms


That's a very good question, so I'll see what I can do. The KBM was devised to get the best out of 'SMAT' type abrasives, which are used by Meguiar's and Optimum. Here is how it differs from the Zenith-Point-Method...

ZPM is a very good technique for getting the best out of diminishing abrasives, which have a time based cut level, and this is a time based technique. The speed is quickly increased, and gradually decreased to extend the work time of the product as far as possible. The skill is mostly in judging the timing. Most of the work is happening within the polish film, and the pad is simply varying the friction level imposed on it.

Non-diminishing abrasives (SMAT SMACKS of marketing, and does not explain what they do .) remain at a consistent size, and the depth of the cut is entirely dependent upon the pressure and pad used to apply them. Time and speed are rendered almost irrelevant (With the Kevin Brown method, you can actually achieve better results with much lower speeds than you otherwise would. As an example, I do most of my compounding these days on speed 3! You'll understand as you read on...). Thus, a different technique is required to get the best out of them. The Kevin Brown Method is based on 4-5 main principals:

1 - Pad Priming 
2 - Cleanliness 
3 - Using pressure to adjust the depth of the cut
4 - Using the pad to adjust the cutting range of the product
5 - (Applicable only to DA's) Changing the speed of the machine changes its orbital pattern in relation to the friction level.

Okay, let's start with pad priming. With SMAT abrasives, you apply polish to the ENTIRE surface of the pad, working it into the material with your fingers until you have created an abrasive 'disc'. Any product added after that point is for lubrication, or 'cleaning' purposes (We'll talk more about this in a minute.). The work is happening _in_ the pad, rather than _between_ the pad and the paint. Using a normal diminishing-abrasive priming technique with 2-4 dots of product results in greatly reduced cutting efficiency, and poor finishing results as the product tends to 'clump' in the areas where you applied the product. Some product will get picked up by the rest of the pad as you work, but in a very uneven fashion, and not enough to saturate the surface. Using an example of MF cutting pads, you are trying to coat every single strand of textile with abrasive particles, so that every strand becomes like a tiny piece of sandpaper. The same thing happens with foam, except the abrasive powder is being attached to the urethane cells, instead of micro-scale threads.

Now on to cleanliness.The lubricants (Mineral oil is most common, though some use water-based polymers, or solvent-based silicones to aid in lubrication.) in the polish are what help to 'buffer' the abrasive from the paint, so they do not cut too deeply, and what also carry away the paint shavings so they too do not act as an abrasive, or clog the pad. These polishing oils are like the oils in your car: they help to prevent excess wear, and isolate particles that could damage your engine. Like engine oil, polishing oils become 'spent', and need to be changed regularly to keep the process working smoothly. The old oils have to be removed (Through brushing, or compressed air.), and new oils put into their place by adding a couple dots of fresh product. Periodically the pad itself has to be changed out, and the priming process repeated, as after awhile the pad will begin to load with spent material beyond what 'new oil' will fix. These old pads are set aside, and washed-out at the end of the detail. Keeping with the automotive analogy, think of this as a 'rebuild'.

Onto pressure. Abrasive 'aggression' is really all about how far that particle is digging into the paint. The farther it digs, the more material it removes, and the more noticeable the scratch is to the naked eye. With diminishing abrasives, they can cut deeply by starting off fairly large in scale, and finish by gradually breaking down until the scratch they leave is too shallow to see. The cut-depth of non-diminishing abrasives is dependent on pressure. If you apply [for example] 7-kgs. of downward pressure over the polishing pad, the abrasives will push through the 'buffer' provided by the lubricants and the pad, and dig deeply into the paint to cut very aggressively. If you reduce pressure on the machine (When 'Jeweling' with non-diminishing, you actually are lifting up on the machine.), the cut once again becomes much shallower. This allows for a huge amount of flexibility, as YOU are in control of how long, how much, and where you want to cut. Let's say you have a RID in the middle of a panel, and some light swirling around it. You could make one pass over the entire panel at moderate pressure to remove the swirl, then focus on the RID in the middle using several high pressure passes, and finish off the lot with a zero-pressure pass to refine.

Let's talk about pads. After my pressure explanation, you're probably wondering why you can't use one pad to compound and finish. Well, it has to do with how the abrasives and lubricant 'sit' on the pad. Basic foam pads are made in two different structures: open, and closed cell. To avoid getting into too big of a discussion, closed-cell works better with non-diminishing abrasives, as their structure prevents over-absorption and waste. What varies the aggression of the pad is how big those 'cells' are; finishing pads use lots of tiny cells, and heavy cutting pads use fewer big cells. The finer cells of finishing pads allow the abrasives to orient themselves in a very fine, very consistent, very tightly spaced layer. This limits the depth at which the abrasives can be pushed into the paint, and helps to maintain a very shallow, very uniform scratch pattern for final finishing. The coarser cells of cutting pads allow more abrasives to be packed into the pad, and more space for the lubricant to go when you apply pressure, which allows the maximum amount of abrasives to be brought into contact with the paint. Thus, the pad adjusts the 'spectrum' of the cut, and it is your job to choose which 'cutting spectrum' matches the range of the defects you are trying to remove. Microfiber pads are kind of unique, because their textile structure allows them to be both 'dense' and 'open' at the same time. They are still a compromise, and in some situations you will not be able to finish down in 1-step (Nor do they have the ultimate gloss of a foam finishing pad.), but they are a much better compromise in many cases than foam. Their larger surface area allows more abrasives to be packed onto a pad, and the free-floating fibers allow those abrasives to be constantly rotated to keep them cutting cleanly. This all translates into more cut, better finishing potential, and less heat than an equivalent foam cutting pad. These pads can also use very stiff foam interface layers, which allows for much better leveling ability than you can get from foam.

Finally, let's talk about speed changing the orbital pattern. Place a mark on one side of your backing plate with a permanent marker, chuck a soft pad into place, and turn the machine on at speed one. You will notice that the pad rotates quite quickly as it orbits. Increase the speed of the machine, and the dot will become a blur as the RPM's increase. Because the stroke length of the machine is fixed, the increase in RPM is increasing the frequency of the orbits, making them tighter. Anyone who owned a 'Spirograph' as a child will understand what this looks like. Reduce the speed to 1 again, and press the pad against your hand. The rotation of the dot you made on the backing plate will immediately slow, as the 'OPM's' (Orbits Per Minute) remain the same. This means that each orbit is getting longer, and smoother, like changing from a small cog on a spirograph to a big one. At this point you may be asking yourself what this is getting at, and how this practically applies to correction. It applies because when you are polishing, the action I have just described is the action the abrasives are following. High-Frequency orbits (Small spirograph cog.) tends to dislodge the abrasives, and cause them to tumble, and even 'grind' against the paint as the pad changes direction. This can be good when you want to cut very aggressively. When you want to achieve a good finish, you want those abrasives moving very smoothly, without any sharp motions (Big spirograph cog). If you reduced pressure at full cutting speed to finish down, the pad would accelerate, and the abrasives will go mad (Even if they are now cutting less deeply.). To reduce cut depth AND achieve a smooth cutting action at the same time, you have to simultaneously reduce speed as you reduce pressure.

I know that this is probably not as simple as you wanted it to be, but to understand the Kevin Brown Method (And how to get the best out of both non-diminishing polishes, and DA polishers.), there is a lot of fairly complex theory you have to get your head around. I hope that I have broken it down so that it is easy to associate, and understand. There are of course finer points which I have glossed over, but this should get you started. Once you start using the KBM with non-diminishing abrasives, and microfiber pads, you may very well think twice about getting a different machine. At the very least, it may change the way you make your choice.

This is the technique I used in my wetsanding thread (http://www.detailingworld.co.uk/forum/showthread.php?t=285957) to remove P2000-3000 defects, and what has turned something many saw as a toy, into a real professional tool. If anyone asks themselves why so many pros are using DA's for compounding, and benching their rotaries, this is why. The difference truly is amazing. We all have Kevin Brown to thank for that. :buffer:

Hopefully this helps...

Steampunk


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## jcentella (Apr 3, 2009)

Wow, that's a really in-depth explanation :thumb:


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## Dift (May 22, 2011)

Brilliant description!


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## Bod42 (Jun 4, 2009)

WOW :doublesho thanks for taking the time to reply with such detail. It is massively appreciated.


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## Steampunk (Aug 11, 2011)

Bod42 said:


> WOW :doublesho thanks for taking the time to reply with such detail. It is massively appreciated.


No problem, mate. If you need anything more, just give me a PM. I think this technique will help you to get more out of your current DA setup...

Steampunk


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## mohebmhanna (Jul 19, 2011)

Excellent information Steampunk, it helped me for a great extend.


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## organisys (Jan 3, 2012)

Thanks!


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## Bod42 (Jun 4, 2009)

Steampunk said:


> No problem, mate. If you need anything more, just give me a PM. I think this technique will help you to get more out of your current DA setup...
> 
> Steampunk


Been reading more on Kevin Brown's technique and its good to read how he does things as this is pretty much what I do. I started polishing my car with the blue plastic version of the cyclone (cant remember the name) and it has no speed control so I soon learnt the best way to manipulate the amount of cut was using pressure. I have always managed to get decent cut from quite a fine/medium polish and pad combo and I think this is all down to the pressure.

I can get great cut with a DA, especially with the new Microfibre pads but just wondered if it was worth stepping up as like the sound of the forced rotations on the Flec.

Steampunk, have you tried the Megs microfibre cutting discs. I only ask as I see that you use the optimum ones and wondered what your thoughts were.


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## Steampunk (Aug 11, 2011)

Bod42 said:


> Been reading more on Kevin Brown's technique and its good to read how he does things as this is pretty much what I do. I started polishing my car with the blue plastic version of the cyclone (cant remember the name) and it has no speed control so I soon learnt the best way to manipulate the amount of cut was using pressure. I have always managed to get decent cut from quite a fine/medium polish and pad combo and I think this is all down to the pressure.
> 
> I can get great cut with a DA, especially with the new Microfibre pads but just wondered if it was worth stepping up as like the sound of the forced rotations on the Flec.
> 
> Steampunk, have you tried the Megs microfibre cutting discs. I only ask as I see that you use the optimum ones and wondered what your thoughts were.


Howdy,

It's interesting how much you can learn doing things the hard way (Either working by hand, or with less than ideal equipment.).

I'll answer your question about MF pads first, and handle the machine question last.

Yes, you are correct in your observation that I only use OPT MF pads (Both cutting and polishing variety.). I have not yet had the opportunity to try the Megs variants, but I have some tests coming up soon between several different MF pads, and should be able to comment more. I have read from reputable sources that the OPT pads finish better than the Megs pads, though I will have to do more testing to determine if they also can cut better. I can certainly 1-step with the OPT MF Polishing pad, whereas I have yet to see someone do that using the Megs system. However, for ultimate leveling and correction power, I am not sure either company has the edge. Other brands offer some promising features that neither Megs or OPT have, and only intensive testing will tell who is on top. There are a lot of features (Textile type, density, length, interface thickness, density, and damping rate, etc.) that come into play, and at this stage I'm just trying to prove some theories before I start spouting off about what works/what doesn't.

The Flex looks a very nice machine (I cannot argue about its quality.), however (And as I believe I said earlier, or at least in another post.), its forced rotation is both a boon and a curse. Its RPM's are quite high (Thus making the orbit tight, as I explained in my post on the KBM.), and the pattern non adjustable. This means you could theoretically achieve some extreme cutting rates, as the RPM's will stay the same, even under very high pressure. However, as you cannot smooth out the orbital pattern, it wouldn't be able to finish down as well as a free-rotating DA. There are two questions that are begged from this discussion, and ones which I have asked myself multiple times:

1. How much cutting potential could I possibly need? 
2. How much finishing potential could I possibly live without?

From my perspective, I can remove so much material, in so little time with my G110V2 and an aggressive combo like M105+MF Pad, that it warrants extreme caution. If I needed more material removal (Or similar, in some cases.), I would also want the _leveling_ potential that wetsanding or [possibly] textile leveling pads could give me. Orange peel really is a drag, and if I'm removing 7-10 microns of material to correct DEEP defects in a panel (Which you can do with alarming ease using an aggressive MF setup and a 'normal' DA polisher.), I don't want to take it with me if I can help it. Rigid MF pads can offer better leveling abilities than foam, but they still won't level as efficiently as sandpaper. Case in point (And I know this isn't going to help your itch to wetsand your car .):


IMGP6943 by Mole Hill Motors, on Flickr


IMGP6670 by Mole Hill Motors, on Flickr

Both achieved the same amount of correction, but on the latter I used aggressive compounding, rather than wetsanding to achieve those results. Both did the job, but the difference is obvious. If I dealt with rock-hard finishes on a regular basis, or had to work faster, my opinion might change, but in the rare circumstances I do I find what I discussed above still applies. If I needed more correction potential/speed, I would look at alternate correction technologies/combinations, rather than alternate tools. The latter allows me to achieve the results I otherwise would with a less powerful machine, but faster. The former takes me into a whole new world of detailing altogether...

I typically deal with softer paint finishes, so finishing down well is always a concern, and it is something that is very difficult to do perfectly. In the end I spend much more time finishing than I do correcting, especially since I discovered MF pads. Technologies that will help me to achieve a perfect finish with greater ease will as such be much more useful to the way in which I work. Your situation may very well be different, so ultimately only you can answer that question with any degree of accuracy.These are simply my findings.

I love to write, and myself am vacillating between upgrading my machine or not, so I guess it depends what you want me to talk you into ? If you have the dosh to try a new machine, and you'll regret not going out on a limb to do so, then do it. I'm this close [holds fingers millimeters apart] from doing it myself. Of the current options the Rupes LHR15 ES is the way I would lean, but the Flex may be what is best for you; I guess only experience will tell. However, if you don't want to make the investment, then your DAS-6 Pro is more than capable of filling the needs of 90%+ of the enthusiasts (In many cases even pros!) out there. The Rupes system is just starting to make waves in the US with the 'big boys', but at this point most of them have shelved their rotaries for Megs and Griot's (Rebranded Kestral) DA's, kitted out with microfiber pads. I think it was Todd Helme who said that "The free-rotation DA is the simplest tool for a beginner to learn, but also the hardest tool to truly master." (Most likely paraphrasing, but you get the gist.), and I wholeheartedly agree with this sentiment. I try to practice with my DA a little bit every day to hone my skills, and have delved deep into the theory behind the technology, but I'm still FAR from discovering the limits of my Meg's potential. My only complaint is the quality; if I could have the same machine made by Metabo it would be perfect, but this is mostly just me being picky. If you're just starting to get to grips with the the teachings of Kevin Brown, there is a lot more performance to be seen from your machine.

Hopefully this helps. I'm sorry if this post got a bit long, but I'm trying to clear out some writer's block, and going a bit overboard on this helped me to get my 'mojo' back. Thank you for asking the questions. 

Steampunk


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## Bod42 (Jun 4, 2009)

Thanks once again for your indepth reply Steampunk, I appreciate you taking the time to answer my questions.


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## Steampunk (Aug 11, 2011)

Bod42 said:


> Thanks once again for your indepth reply Steampunk, I appreciate you taking the time to answer my questions.


No problem, glad to help. :thumb:

Steampunk


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