How many times can you use M105 before wearing through the clear?

[imported_Flash Gordon]

If you`re old enough to remember the old Tootsie Roll Pop commercials with the kid asking everyone "how many licks does it take to get the center of a Tootsie Roll Pop?" you know that nobody could answer him. Except for the owl, who took three licks and bit into the candy, revealing the tootsie roll center. His answer? Three. A narrator`s voice then repeats the question and provides his own answer: "How many licks does it take to get to the center of a Tootsie Roll Pop? The world may never know."

http://www.youtube.com/watch?v=2IA5Cv_5-g8

What a great analogy

[Legacy99]

IME I usually remove .1 mill and never more then .2 when doing an extreme correction. .2 mill removal is pretty rare. Once you get your car corrected, you should not have to do a heavy correction for 12-18 months if you are using proper washing techniques.

On a newer C6 vette I can tell you that the clear is approx 3.5 mills thick. But I can not tell you how thick the clear is on any metal based panel.

Exactly, after correction you shouldn`t need more than SIP or Wolfgang 3.0 TSR. I`m going on 4 years with the same car that is a daily driver with no garage and never used more than 85rd and Ultrafina. At this rate I could polish for 20 yrs. with no clear coat problem.

[Leadfootluke]

Beautiful post Todd.

It is my understanding that our 5 year old vehicle has never had a paint correction. I intend on doing a full correction to the best of my abilities, and then protect it. From that point forward, periodically use M205 and/or a finer polish to keep the paint looking good. I don`t fear overusing M105, but I think once it has accomplished its job, M205 can be used to maintain the finish and avoid letting the paint get too swirled.

[imported_Bunky]

I realize there is no exact formula but despite my searches of some forums I could not find any real answer. There are all sorts of cute responses but I was looking for some pragmatic idea.

Mike Phillips did say on another forum that he knew very few people who have buffed through their clearcoat using a DA. Then, Mike posted an experiment he did with various steps (wetsanding, buffing, etc) and it showed that a DA will not remove much. Of course you have to watch for corners, etc.

[imported_Luster]

If you`re really observant and have good eyes, you can usually see if the clear is getting thin.

It will have a "frosty" appearance. Not typical hazing that some compounds leave, but more of a very subtle crackly appearance. (obviously hard to describe).

I was polishing a `64 Corvette (re-painted in the late `90`s with base-clear), and I noticed that the area at the top of the doors wouldn`t shine like the rest of the car.

Close observation showed that the clear was nearly worn through.

I stopped immediately... VERY lightly polished with M205 and a black pad... (NO PRESSURE! Just a few passes with the weight of the machine). This put a little shine back on the paint surface. Then coated with 2 layers of BFWD and left it alone.

In the picture below, it`s nearly impossible to see unless you`re inches away. I could also feel a slightly rougher texture to the paint in the affected area.

It`s directly above the window on the top of the door. (As I said, easier to "feel" than to see.)

[Michael Stoops]

Luster`s post brings up a very important aspect of this that is rarely addressed; whether you`re rotary polishing, wet sanding or doing anything else, it isn`t a matter of "I didn`t go through the clear", it`s a matter of "how much clear did you remove?" Look at the service manuals from virtually any auto manufacturer and it will say something along the lines of "removing more than 0.5mil of clear will require a refinishing of the vehicle".

Consider that the average factory clear coat is approximately 2.0mils thick - that`s 2/1000 of an inch. Not much. Consider further that the clear coat provides the UV protection that keeps the color coat below from fading and/or other damage that can lead to problems such as delamination of the clear. Problem is, as the clear coat dries the UV protective components tend to migrate toward the surface. So removing half of the clear removes more than half of the UV protection. And what of that almost universal admonition to not remove more than 0.5mil? Yeah, that`s only 1/4 of the total clear coat. It`s 5/10,000 of an inch.

People tend to think they`re perfectly fine if they "don`t go through the clear", but you don`t need to go all the way through to run into problems. True, going through the clear poses a problem right now, but thinning it down to almost nothing poses problems down the road. Chief among those is premature clear coat failure.

And we all know how easy that is to stop once it gets started. :cursing: