Scientific Study quantifies automatic car wash swirls

[Mary S]

I have been talking to some people who belong to an organization called "Professional Carwashing and Detailing."

It is interesting that even with the name Detailing in their title, I don't think the word detailing to them means the same as it does to people here. I think it is mostly add-on services to an automatic wash.

In any case, someone directed me to this write-up of a study done comparing hand washing to automatic car washing. They compared the damage that was done by 4 people who were told to hand wash their car but no method was given as to how. And a 5th car went to an automatic wash. So the results to the paint were compared after 25 washes over the course of a year.

I warn you that this article is very biased against hand-washing.

http://www.autobell.com/comparison.htm

This is the paragraph I find interesting:

By comparison, the surfaces of the test vehicle washed with automatic carwashing equipment appeared different. Compared with the hand washed surfaces, it was remarkably smooth, with many very fine markings virtually parallel and uniform - less than .0003mm - the result of evenly moving and rotating cloth pads and curtains. The machine-washed surfaces were in very good condition after 25 washes.

These fine parallel and uniform markings are what we see as swirls.

And in this trial, the people who didn't know what they were doing when handwashing their cars, their scratches were not as uniform and some were deeper, as you would expect.

But what is interesting is that somebody studied exactly what 25 automatic washes over the course of a year would do to a car's finish. This part of the study would be interesting to see.

It is also kind of interesting that the members of this organization sincerely did not know what swirls were.

[Zuke]

Re: Scientific Study quantifies automatic car wash swirls

Hmm... is the University of Texas at Arlington assuming we are hand washing with dawm soap and SOS pads? I don't see how the can claim a hand wash is bad for your paint.......

[Mary S]

Re: Scientific Study quantifies automatic car wash swirls

Hmm... is the University of Texas at Arlington assuming we are hand washing with dawm soap and SOS pads? I don't see how the can claim a hand wash is bad for your paint.......

LOL That possibility sure wasn't ruled out!

Plus the half a bucket of water and a dirty shop rag, see how many times you can drop it on the garage floor method.

That's just it, they were just told to wash thoroughly, not told how to do it.

They did mention, though, that the brushes with the flow-through water were not good.

[J. A. Michaels]

Re: Scientific Study quantifies automatic car wash swirls

As you stated. Very biased toward the Automatic car wash.

It would be interesting to have them conduct the same study, with 5 of us washing a car. How could they skew the results then? lol

Thanks for the article.

[RaskyR1]

Re: Scientific Study quantifies automatic car wash swirls

Having managed a full service car wash back in the day I can assure you that study is a joke! On top of our full service tunnel wash we offered detailing and we also had the "auto swirl"...I mean "auto buff" machines for applying paint sealants. It basically involved a person applying the sealant to the painted surfaces with a spray gun and then letting one those god awful machines slap the paint with those soft *stiff* cloth mops! Sure it made the paint feel smooth, but the fine scratching could clearly be seen. Needless to say I quit working there not long after taking the job.


What's really funny is that one of my friends literally just emailed me a link to a local car wash today that had that study listed in their FAQ section. He was asking whether it was true or not because his wife wants to have her car washed there on a regular basis.....this is after having me detail it last fall.

[Mike Pennington]

Re: Scientific Study quantifies automatic car wash swirls

While it is ok to keep this thread alive, keep in mind, we do not need to bash or offend any organization or people affiliated with an organization....

Thanks for understanding!

[Mary S]

Re: Scientific Study quantifies automatic car wash swirls

While it is ok to keep this thread alive, keep in mind, we do not need to bash or offend any organization or people affiliated with an organization....

Thanks for understanding!

Mike, if you are referring to PCDA, if I sounded like I was bashing their members, that certainly wasn't my intention. It just appeared to me that this organization was mostly automated car wash owners and operators, some of whom also offer what they call "detail" services, including one near me. They will vacuum, wash your interior windows, apply Rain-X, wipe down the dash, console, steering column, door jambs, apply tire shine, all as additional services to their basic service, and they refer to it as express detailing. They also offer both a spray wax and a hand wax.

The thread I had posted was about the touchless automated wash, and I guess I can only speak for the people responding to that thread. I had to spend at least 3 or 4 posts explaining to them what swirls were and showing them pictures.

In the process, there were people claiming that the 2 bucket handwashing technique was inferior to the automatic wash, and they made some good points, that their method is constantly flooding the fibers with a diluted wash solution during the friction part, and the pass with the mitt isn't and could drag particles across the car's paint. So I spent quite a few posts also defending the hand wash technique.

So I apologize for generalizing about their members. I literally found it "interesting" that an organization for car washing and detailing had predominantly car wash owner members compared to detailers. But all it would take is for the detailers to join.

I find it "interesting" too that the car care forums like this one tend to warn people not to use automated car washes and that apparently, from what I could see from the site, the predominant position is that automated car washes are better than hand washing.

But my own intention has been to see if it is possible to moderate our position on automatic washes in some cases.

So again, I apologize if I sounded like I was bashing.

[Mary S]

Re: Scientific Study quantifies automatic car wash swirls

It would be interesting to have them conduct the same study, with 5 of us washing a car. How could they skew the results then? lol

There is no reason that test couldn't be added. They don't need to repeat the test of that particular car wash plus 4 random do-it-yourself washers.

Plus, considering the fact they apparently only tested one automated wash, which I gather was a fabric friction wash, they could also add a test for what a closed foam technique wash does.

I like to quantify things exactly. I don't like to just say "hand washing is good, automatic washing is bad." I was a software tester for most of my career, I don't know if that is why, but I want to be able to see specific results of a test. For instance, if you correctly use a boar's hair brush, will it scratch the paint.

The fact someone actually did a study on automated washes at all, that is a good thing. I am going to try to track that report down.

[TOGWT]

Re: Scientific Study quantifies automatic car wash swirls

http://www.mbfanatics.org/forum/index.php?showtopic=353

[Michael Stoops]

Re: Scientific Study quantifies automatic car wash swirls

We know of some very high quality automatic car washes, and some really bad ones. We've seen people wash their cars repeatedly at home in such a way as to inflict almost no marring at all, even over time. We've also seen people washing at home with dish detergent and an old towel that they drop on the ground a few times during the wash.

Bottom line: there is a right way and a wrong way to perform any process.

[Mary S]

Re: Scientific Study quantifies automatic car wash swirls

We know of some very high quality automatic car washes, and some really bad ones. We've seen people wash their cars repeatedly at home in such a way as to inflict almost no marring at all, even over time. We've also seen people washing at home with dish detergent and an old towel that they drop on the ground a few times during the wash.

Bottom line: there is a right way and a wrong way to perform any process.

Very well said!

[Mary S]

Re: Scientific Study quantifies automatic car wash swirls

http://www.mbfanatics.org/forum/index.php?showtopic=353

It is interesting how similar these 2 studies are.

This looks rather significant:

"Before each washing, the test vehicles were coated with a mix of street dirt, under-fender accumulation, oily water and thawing-salt residue. The grit particles in the mixture were heavy enough to damage the toughest painted surface."

This looks like the condition of a car that hasn't been washed all winter. Okay, if that is an exaggeration, at least one can say that there aren't too many climates (I can't think of any) that will do this to a car on a biweekly basis over the period of a whole year.

As a person hand washing a car by whatever method I deemed appropriate, I think my hand washing technique would be to take the car through my local touchless wash then bring it home and wash and wax it in the usual way, considering if it was covered with thawing salt residue, it is time for a wax anyway. Or at least use Meguiar's Wash and Wax.

[CharlieATL]

Re: Scientific Study quantifies automatic car wash swirls

Does anyone have access to the original study that was conducted by the University of Texas? This thing appears to be widely quoted by the automated car wash industry, and I'd certainly like to see original data. Thanks.

[Karlsbad]

Re: Scientific Study quantifies automatic car wash swirls

I am an industrial engineer in a FDA regulated environment and I know a thing or two about conducting "scientific" studies to ASTM standards.

In my younger days I built surfboards professionally for 26+ years and worked in a vintage car restoration shop too. So I also know a thing or two about car care and polishing polyester, lacquer and 2 stage clear coats.

I looked at the testing criteria and read the conclusion of that "study" and it only proves that if a person doesn't understand how to do a process they will generate unexpected results...that's all, nothing more.

(you might want to note the automatic car wash was run by trained persons on how to correctly run the process...why not match apples for apples... I would bet my money on a trained professional doing 25 correct two bucket washes over ANY automated car wash on the planet)

It is obvious that study was setup to produce results congruent with the entity that funded it. Anytime an entity funds a "study" with financial gain riding on the outcome... the results must be taken with a grain of salt. I don’t care if it in my industry Biotech / Pharmaceutical or the automatic car wash assoc of America.

Now if an independent organization funded such a study to ASTM standards and ran it scientifically with different variations... people trained in correct two bucket vs. people doing "whatever"...different types of automated car washes, control groups etc...Then I might be interested.

There was absolutely nothing "scientific" about the study. It should be viewed as a paid advertisement nothing more nothing less.

The simple fact The international Car Wash Assoc. decided it was necessary to "prove" a point (and try to scare people from washing a car at home)...should be a tip off all by itself.

[jfelbab]

Re: Scientific Study quantifies automatic car wash swirls

Here is the link to the Texas study: http://villagecarwash.net/pdf/TexasCarWashStudy.pdf

The study is correct in it's assumptions. The average Joe doesn't wash his car well at all. As an example, my neighbor to the west drives a black BMW. He washes his car with a small, grungy two gallon plastic bucket that I've seen him use in the garden, with some dish wash soap and an old wash cloth. The same wash cloth is used every couple weeks and is not laundered between washings. He claims it gets clean in the soapy water. He dries his car with an old bath towel that only gets laundered when it gets stiff. His black BMW is grey in the afternoon sun due to all the swirls. This is your typical home car wash folks. Look around at your friends and neighbors and I'd bet you need not look far to find similar home car washing techniques displayed. For these types, the automatic carwash would be less damaging.

If the study were to compare our washing techniques, I'm also equally sure that ours would win the test. We all, at least I hope we all, wash our cars using the two bucket method with quality car wash, properly measured, and use clean plush wash mitts, or some equally high quality method. I also hope we all dry our cars using the sheeting method and then blow off, or blot off, the remaining water with a clean waffle-weave micro-fiber towel or two. We are not the target audience for this study nor for the automated carwash industry.

That said, I live in the snow belt where I drive in snow/salt/sand, in below freezing temps, often below zero, for around three months out of every year. I use an automatic wash in the winter. I use a touch-less wash to get the salt, sand, and winter crud off the car and the underbody flush also is a plus. I do take the car home immediately after and give it a wipe-down with M135 (UWD) and then D156 (UQW) after these washes and I've noticed no additional swirling. I'm reminded that this season is fast approaching as it was 35