Failing Clearcoat?

I

imported_Indy YZF

New member
Does anyone know, or personally experienced, what a clear coat, that hasnt actually failed yet, ie, it hasnt peeled off anywhere, but might be on the verge of failing looks like upon close inspection under the lights?



Theres an area on the leading 24" of my hood all across, where I used to use a hood bra and developed some surface marring, that Ive done quite a bit of polishing to smooth out the scratching...Ive done a pretty good job in the most of the scratching is gone..



The area is smooth as silk, and very shiny....But, under close inspection with lights, you can see loads of tiny pinholes pretty closely spaced, in the surface. You cannot feel them at all. And unless its under indoor lights, it looks incredibly shiny and deep. So, whats causing this?



I know were' not supposed to trust those Marr-Hyde magnetic paint gauges, but it detects no difference in the depth of the finish there or elsewhere where I have not done any deep polishing.



So, does anybody have any idea what this is? The harshest stuff Ive used on the hood is 3M FI and Meguiars #2, applied with both an orbital, and just a tiny bit of work with a slow speed (1600 rpm) Wen rotary. And I havent really done much of it at all.
 
It'a one of two things, you removed to much clear coat and you are now in the sponge part of the clear, or they are acid rain pits.



I'm thinking you removed to much clear, just keep the paint protected, if the clear fails you will know.
 
I'm thinking you removed to much clear, just keep the paint protected, if the clear fails you will know
Click to expand...



That sounds intesting...What is this 'sponge part of the clear...'?



I think your right...Anything environmental would have hit the hole car, not just the part where Ive concentrated most on micro-marring and fine scratches thanks to that damn bra....But Im surpirsed the clear wore away so quickly......afterall, Ive done no sanding, havent used anything more aggressive than 3M moderate strength cleaner wax by hand, and 3m FI by rotary, but no faster than 1600 rpms, and not for long.



As I said, in the sun, it looks perfect...A really enviable finish...Only under the indoor lights, and only at an angle, can you detect the issue. I was thinking of having a body shop respray the clear on that area of the hood...But then I said, hell, since I know better than to use a bra again, the hood will probably get some more road dings, rock chips, and other kinds of damage before long...why dont I wait a while, til it gets some real damage, and then do it...Or, maybe I should wait til I get a frontal fender bender, and then have the INsurance company pay for it!



But, Im so anal compulsive about the car, I need everything to be just 'perfect'..You know, its possible to love a car to death!
 
I have the perfect solution for you!!



Give the car to me and I'll fix it up... and keep it! :D



Sorry, I couldn't resist! Oh what I would give to have a supercharged E36 M3 in my garage ;)
 
The sponge part of the clear coat is lower and more porous part of the clear, if you magnified it 5000x it would look like a sponge.



Todays clear coats are very thin 1.5 to 2.0 mils a mill equals 1/1,000 of an inch. If you remove more than .3 mil of clear you also removed all the UV blockers for they are concentrated in the upper 1/2 mil of the clear If you remove more than .3 mil of the clear it may fail, and it's not hard to remove that much clear even with a very fine compound or glaze.



Buffimg a newer clear with a wool or foam pad at ( 1600 rpm ) is somthing i would not reccomend, todays clears just don't like heat.
 
Buffimg a newer clear with a wool or foam pad at ( 1600 rpm ) is somthing i would not reccomend, todays clears just don't like heat.
Click to expand...



Well that really sucks...Because it means that, for all intents and purposes, there is no way to remove minor scratches even if they only live in the clear coat layer.



If all we have is .3 mils to work with, than almost any attempt to get out a micro scratch in the clear layer will result in removing that much.



as for the diagnoses here, I agree..I probably have removed a slight bit too much clear...However, under most lighting, it still looks phenomenal. Since the pinholing has no feelable texture to it, Im pretty sure its not going to fail....Since hoods regularly get dinged with rocks, bugs, and stuff, I'll probably wait til its really damaged and then either have it repainted, or, maybe I'll just replace the hood with a carbon fiber job, and leave it unpainted!



How much should a good bodyl shop charge for such hood repair? Color is alpine white, so color match is a no brainer. BTW, do you think I can just have the clear redone, or does the color need to be resprayed also...Theres no damage to the color layer I can detect.



thanks.
 
paul e said:
How much should a good bodyl shop charge for such hood repair? Color is alpine white, so color match is a no brainer. BTW, do you think I can just have the clear redone, or does the color need to be resprayed also...Theres no damage to the color layer I can detect.
Click to expand...



paul, Chris here... I made it to the board.:xyxthumbs On a previous car I had a hood resprayed due to some minor hail damage, and it cost me $600. That was to completely strip, primer, paint and clearcoat. I would plan on at least 450 to 500 to respray though. As for just doing the clear, I've never heard of that, I wouldn't think that to be possible. I just spoke to the guy I've used a few times, and he says redoing just the clear isn't really possible.



Did I hear you say something about a CF hood, and NOT painting it? Would you be so bold???? I was thinking when and if I need to respray my hood, I might consider going CF and not painting it...But that's on a black car... ;)



If you'd like, I can get you in touch with my friend, he's in Mamaroneck. very nice guy, does great work, and won't try to rip you off with cost, at all.



regards...
 
Paul e, yes it does suck but one can remove minor scratches or micro hazing AKA swirl marks using the proper technique, a good foam pad and a rotary at no more than 1500 rpm, "i like to use mine at 1000 to 1250" and the proper glaze or fine compound. The hotter the clear is the more elastic it becomes, The scretch or imperfection you are trying to remove moves deeper into the clear as the heat increases.



Any scratch you can feel is often to deep to remove.
 
If you'd like, I can get you in touch with my friend, he's in Mamaroneck. very nice guy, does great work, and won't try to rip you off with cost, at all.
Click to expand...



Chris, thats a terrific offer... From one M3 owner to another! I took another close look at the hood area today, and I think I might ahve over reacted....Overall, its got a terrfic shine. Its very hard to see that teh area of concern is not perfectly smooth and free of defects...Only at certain angles of light, can you see what looks like light dust or haze in the clear....Its mostly smooth and glassy, so, I think Im going to keep it as is Ive shown it to a few people, and they think Im crazy...the say they only wish their cars ever looked half this good...So I think maybe my perfective tendencies when it comes to this car have gotten the upper hand...But still, Im in White plains, so a good, honest body or paint man in Mamaroneck would be great for me to have...Thanks.



>>The scretch or imperfection you are trying to remove moves deeper into the clear as the heat increases. Any scratch you can feel is often to deep to remove<<



I didnt know that....I think swirls are easy for me to remove...Its the scratching in the clear coat layer brought on by use of a damn bra (Im going to burn mine..Im old enough to remember when 'burn the bra' was just a slogan! :shocked ) Any way, these were never deep enough to be able to feel, and I know they were only in the clear layer...But the problem is that the clear layer is 2 mils thick, but you can only safely remove .3 mil..Which means almost any scratch, even though its in the top part of the clear, will go deeper than .3 mils...About the only kind of micromarring which wont is swirls which are really right on and not 'in' the surface. I wish theyd give us another 2 or 3 mils of clear...At least that way, wed have something to repair into. I think that from now on, Im going to try and stay away from the rotary, and go with the porter cable oribital only, used with glaze thats non or only very slightly abrasive.



As for the area in question, I really dont think its bad enough to worry about now. I'll wait for more scratches, rock dings, or other damage which undoubtedly will occur, and then the $500 it will cost to repair will really be worth it. No sense in repairing what everybody else thinks looks perfect.



Thanks for all your help.
 
You must log in or register to reply here.
Back
Top