Pitting in clear coat?

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DetailFreak22

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I noticed this sort of "pitting" in the clearcoat after polishing. I have a 2009 BMW M3 with the factory carbon fiber roof. I'm using a RUPES bigfoot with a chemical guys blue foam pad, and their V36 polish. The "pitting" cannot be felt with my fingers. It can't be removed with a 50/50 mix of alcohol/water either. I asked Chemical Guys and they said it was clear coat failure after I sent photos.

I'm not a professional detailer by any means. But I don't see how the clear coat could have failed with a DA and a medium-light polishing compound. I didn't do too many passes. I didn't even spend that much time on the roof. I did 2'x2' areas, spread with setting 1 and then worked up to setting 6. I also noticed this same "pitting" on the gloss black window trim, and on the trunk of the car (not carbon fiber, just factory space gray paint). It's not as bad as on the roof. I haven't noticed this on any other panels on the car. I know it's from polishing because it only showed up on one half of the roof (I didn't polish the other half after seeing the results).

It sort of has this cloudy look. In most conditions it looks perfectly fine. But under direct light from the sun or from overhead lighting you can see it. Have you seen anything like this before?

Photos attached. Look where the light source is in each photo to see the "pitting".

The third photo shows much less pitting than the others. This is the front of the roof, closest to the hood of the car. This is where I started. The pitting gets worse the closer you get to the back of the car. Maybe the polish was breaking down? I noticed the polish started to spread dust. They claim the V36 polish compound is not supposed to spread residue. The first few panels I did with the pad there was no dust residue.

I'd like to know what caused this to happen and how I can prevent it in the future. Was it my technique? Was it the product breaking down? Was it the pad getting old?
 
hard to tell with those pics. it almost looks like crows feet failure but i wouldn't describe that as pitting.

if it's pitting, i have experienced this sort of thing before with even factory finishes...sort of like tiny pinholes. apparently, it can be slight solvent pop that occurred when the layers underneath the clear tried to outgas or even the lowest portion of the clear tried to outgas when the topmost surface of the clear started to cure too fast.

by polishing, you remove the clear that barely filled the top of the pinholes/pores and expose the paths where the solvent "outgassed" during curing.

EDIT: i noticed you said it's a 2009. is it possible that car was corrected heavily prior to you owning it? i am curious how thin the clear is on those carbon roofs in the first place.

i wish i could see higher quality images of the areas in question. the image hosting limits for this forum SUCK.
 
While you can say that there's pitting in the clear coat due to possible gassing, in fact, Mike has some postings from cars with a base/clear coat system. However, since you have Carbon Fiber, it's a different animal.

Just to give you a back round, I have a dragster that I race in Comp Eliminator on the West Coast. In order to keep weight down, many components on the car are made of Carbon Fiber, including, parts of the Body, Wing, Scoop, Cowl, Seat, Nose, Brakes, Helmet and Floor Boards. Depending on who does the Carbon Work, there are different methods of using Carbon during the molding process. Some people go with a pre-pegged Carbon, which has Resin build into the carbon. This helps with production because it speeds up the production process because the producer doesn't need to lay down resin to carbon prior to placing the carbon in mold prior to the autoclave process. Moreover, some would tell you that the pre-pegged method of Carbon produces stronger end product because the resin is more evenly distributed over the substrate of the carbon, resulting in a lighter product.

While, this a good method, some will prefer to go with different resins, depending on the application needs, and will not go to the pre-pegged method. This when the resin is applied similarly to Fiberglass. Because of this, you have more flexibility of different resins.

From there, the Carbon is placed in a Auto Clave where the Carbon is heated and placed under Vacuum to get the Carbon to mold with the mold for the end product and heat up the resin to about 130 degrees to activate the resin. Between the vacuum and heat applied to it, the resin takes the shape of the mold and the substrate of the Carbon Fiber.

Because of the weaving of the Carbon, a cris cross pattern, the Carbon shows little pin holes in the Carbon after the end product has been taken out of the mold. If you ever care to look, you can buy a piece of Carbon Fiber, or, Kevlar and hold it up to a light to see that there are small holes when the light protrudes thru the substrate of the fabric.

I have seen this end result from more than one producer of the Carbon Fiber products. When I asked my painter about it, the only thing that he told me is that he lays down a building coat of clear, repeats the process more like a show car effect. He even went further to say that he may have to spot touch each hole in order to fill the holes with clear and then sand, level, and buff to have a uniform end product.

On the cowl area of my car, there was a lot of block sanding that went on along with using a heaving filling epoxy primer to help with this issue.

Reading thru your post, you'd mentioned that there's dull finish on the Carbon Fiber, and this is from the type of resin that is used. Sometimes, the Carbon has a milky like appearance. It has to do with the amount of heat used in the AutoClave and the Resin used for it. From my understanding, it helps with the overall strength of the end product.

I know that Mike will refer you to the respective paint and/or car maker for this issue; however, I would direct you to:

https://www.facebook.com/sdenterprises432

These guys paint a lot of Carbon Fiber Bodies, as you will see from their Facebook Page. As a result, they would be able to help you.

In addition, you can contact Aerodine Composites:

Aerodine Composites Group

Once you are able to talk to these people, you will have a better idea on which direction you may want to get with it. Lastly, you will want to be aware of yellowing from UV rays that happens to resin overtime similar to what you see in Plastic Headlight lenses. In fact, it has been an issue with Porsche on many of their Carbon Fiber parts on their respective cars.

That being said, you may find that you that you've opened a pandor's box and may decide to have someone re-shoot clear on it, or, live with it. Some people may even consider going with a Vinyl Wrap and/or 3M Clear Bra on top of the Carbon to protect it since it would be very expensive to have it replaced and/or bodywork done to it.

I hope this helps you.
 
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Hard to tell, but they just look like DA pigtails to me... in which case it was caused by using a dirty / old pad and can be removed with a finer polish (and clean pad).
 
It would be helpful if you could take a close up picture. Aim more directly at the problem area, all of the background in the photos posted is out of focus and therefore useless.

Just try and fill the entire frame up with part of the overhead light in the reflection. Get as close as you can while maintaining lens focus.
 
Thanks for the replies. It's very difficult to get a clear pic. It only shows up under certain lighting. I'll try to get a better picture. I suspect it's due to the pad being dirty because the same thing happened to my trunk a little after polishing. I started at the front of the car. I'll tru again with a brand new pad and a finer polish
 
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