Run out of Clear Coat

G

gandblah

New member
Folks
I've been spending a lot of time on this forum just reading up and learning. Had a question - hope it's not a silly one.

I've heard of people using cutting pads to take care of scratches and swirls. I understand that the pad and polish combo gently abrades the finish till it's brought down to the depth of the original scratch hence eliminating the scratch/swirl.

Question is - how many of these polishing sessions can you do on a cars surface before you abrade the clear coat down to the base coat? I would assume that at some poit in time you would run out of clear coat to work with right?
 
I've never heard of anyone running out generally, but I've seen burnt through spots. I would guess you could polish seasonally for 10 years on most paints, and if you don't make a mistake, it should be okay.
 
They also make gauges to tell you how thick the paint is. I lot of high end detailers use these on expensive cars as to not burn through the paint. I think you should be fine. I would not want to polish and more than you have to. I think once or twice a year would be all I would want to polish. If you wash properly and seal your paint, you should not have to polish more than that.
 
gandblah said:
I understand that the pad and polish combo gently abrades the finish till it's brought down to the depth of the original scratch hence eliminating the scratch/swirl.
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Incorrect. When you use the combo that you speak of the scratch (the dip in the clear coat at microscopic level) is not eliminated rather it becomes invisible to the naked eye. The scratch is visible due to light diffraction. What the combo does is round the edge of the scratch so light is no longer diffracted and the scratch becomes invisible in other words eliminates the scratch.

Also like others have stated don't worry about running out of clear coat it won't happen. But this also doesn't mean to be careless and polish like you are polishing metal.
 
You people claiming that you can't run out of clear coat better re-think your approach. You can and will go through the clear with enough polishing. You are removing clear and leveling the paint when you correct defects. The clear is non renewable. When it's gone it's gone and you need a repaint. You will know when you burn through but you don't have to burn through to remove too much. Remove enough clear coat and you end up with clear coat failure down the road. As for the paint gauges they are good if you know what you are starting with. Unless you know for sure the history off the car you can't really know how much clear you can safely remove. Those gauges tell you how much material is between it and the metal. How much of that is primer, base coat, or clear coat it can't say. Best advise is to use the least aggressive product/pad combo to do the job and be totally anal in your wash and dry technique to preserve the finish and minimize the need to use an abrasive.
 
Anthony has brought up some very good points.

The only way to tell how much finish is on your car will be with a gauge, but that gauge will not tell you how much of that finish is clearcoat.
Someone had a list of what many car companies used for base and clear thinkness, if anyone has a link or knowledge of thicknesses it would help. If I rember it's only about 10 mils for paint & clear combined

So it is possible to go through the clear, that is why it is important to use the least agressive combo first.

I doubt that regular polishing (2-3 times a year) will be wearing out your clear, but that will depend on how agressive people have been in the past and how agressive people are with it now.
I have read threads where people with brand new cars are asking about starting with SSR2.5... Can't see why they would be using that on new paint.

People should use the right product to accomplish the job.
I can kill a fly as quick with a swatter than as with a wrecking ball :wink:

"J"
 
I use a body shop paint depth tool which digitally and acurately measures both clear coat thickness and single stagepaint thinkness.
 
DKKNE said:
I use a body shop paint depth tool which digitally and acurately measures both clear coat thickness and single stagepaint thinkness.
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You have a link to this gauge? You sure it can distinguish how much base coat and how much clear coat there is? I have never heard of such a gauge.
 
DKKNE said:
really? Body shops use it all the time. There are several that work well:

http://www.measureitall.com/ultrasonic/pt100/

http://www.promotorcarproducts.com/etga.htm

http://www.paintmeter.com/eng/index_cbm.html

http://www.paintthicknessgauges.com/

There is also the magnetic one that is acutrate too: http://www.promotorcarproducts.com/progauge2.htm
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Thanks for the links especially the video. That guy was amusing.

I don't think I made myself clear with my comment about the gauges. I know that there are gauges that will measure "paint thickness". The problem with this, as the video of the guy demonstrating the use of one of the gauges shows, is that you get a number. That number is total material on the metal. How much of that is clear coat? How much is base coat? You get a reading of 4.9 mil like the guy in the video how much is clear coat? Is it 2 mil or 1? Unless you know that you don't know how much clear you have to work with. In the video he got a reading of 14 mil on the fender of the one car. Obviously a repaint. That could be 13 mil of primer and base coat and only 1 mil of clear coat.

The first link you provided seems to have a gauge that is able to measure different/multiple layers. That one is interesting and is the first time I have seen it's type. The others are your typical single layer gauges.
 
Anthony A said:
Thanks for the links especially the video. That guy was amusing.

I don't think I made myself clear with my comment about the gauges. I know that there are gauges that will measure "paint thickness". The problem with this, as the video of the guy demonstrating the use of one of the gauges shows, is that you get a number. That number is total material on the metal. How much of that is clear coat? How much is base coat? You get a reading of 4.9 mil like the guy in the video how much is clear coat? Is it 2 mil or 1? Unless you know that you don't know how much clear you have to work with. In the video he got a reading of 14 mil on the fender of the one car. Obviously a repaint. That could be 13 mil of primer and base coat and only 1 mil of clear coat.

The first link you provided seems to have a gauge that is able to measure different/multiple layers. That one is interesting and is the first time I have seen it's type. The others are your typical single layer gauges.
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well I guess you woudl have to get a little more technical and brush up on the paint process. The measurement + your knowledge of what type of paint was used will give you a good idea of how much you can take off.
 
DKKNE said:
well I guess you would have to get a little more technical and brush up on the paint process. The measurement + your knowledge of what type of paint was used will give you a good idea of how much you can take off.
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How would that help? I bring you a car and ask you to detail it. How can you possibly know how much clear is on there? It may have been polished 30 times previously or never. It may be repainted or not. Not all repaints are thick like the one in the video.

Unless that gauge can separately measure clear and base coat you don't know where you are starting from.
 
Anthony A said:
How would that help? I bring you a car and ask you to detail it. How can you possibly know how much clear is on there? It may have been polished 30 times previously or never. It may be repainted or not. Not all repaints are thick like the one in the video.

Unless that gauge can separately measure clear and base coat you don't know where you are starting from.
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Some of the ultrasonic gauges can tell you each layer. I personally use my eye and experience and have never been surpised yet. Not every car needs to be buffed with a wool or course foam pad either. :howdy
 
DKKNE said:
Some of the ultrasonic gauges can tell you each layer. I personally use my eye and experience and have never been surpised yet. Not every car needs to be buffed with a wool or course foam pad either. :howdy
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You can tell the paint thickness with your eyes? OK.
 
I used SSR2.5 and the Edge green pad on my 5 year old Silver Jeep today... and I thought that was a lot. Hope I didnt take too much clear off.
 
DKKNE said:
my eyes and skill yes. I am not afriad to buff anything , and I have never ruined paint ... ever.
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Care to explain to me how your eyes can determine how much clear coat is on the car? You claim to be able to do something that is beyond belief. We're talking mils of material here. Beyond paper thin.
 
I said Eyes and skill. When the clear coat becomes dangerously thin, the color underneath it ( aside from white and cream colored cars, in which case your screwed LOL ) has a slightly differnt color shift to it. Also you can usually tell if there is sun damage underneath the clear, also indictive of a thin clear coat.

There are a myrid of other signs too, so basiclaly when you are ready to attack a nasty scratch or woll pad a car, just take a few minutes to walk around the car, look at each body panel and when thinking of how a body shop can "blend" panels, watch for differnt finish patterns, orange peel differences , or any signs of previous repair. What I have foudn is 60% of the time, that refinished panel has been wet sanded and buffed hard to remove imperfections therefore leaving very little clrearcoat left.

Also when you take the above mentioned paint depth tool, and come across a low readin, you know the clear coat is thin. It really common sense if you think about it, hence my fashionation as to how you couldn;t come to that deduction without simple reasoning instead of attacking me and my knowledge Anthony
 
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