The Camaro Club (UK)
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WTF is wrong with the paint?!
http://classiccamaroclub.mfatw.com/viewtopic.php?f=9&t=1998		 Page 1 of 4
Author:  78 Camaro [Sat Oct 08, 2011 11:59 pm ]
Post subject:  WTF is wrong with the paint?!
Hi,
So after working lots and taking a long holiday im back and back on the camaro. Thought i would cut n buff in order to get the glass in, then do the exhaust and get it on the road and deal with little stuff as it goes as it's that near to completion now. So i get all the sanding paper, water etc ready, go over my notes from the past 2 years and start in with 1,000 grit to start cutting back the orange peel. thought i'd start on the roof and work my way down. So i'm working the roof and then these ghost lines start appearing. wtf :evil: I have no clue what they are, what's causing them, but most importantly - how to solve this issue. Pics below. It appears as if am cutting into the next layer of paint maybe? but why the dark border?? and as i try an cut back the border it moves further away - i.e it started as a patch, now it's bigger than the sanding block. what's goin on?! :shock: Anyone know what it is? or how to solve it????? thanks in advance for your help!

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Author:  70 z28 [Sun Oct 09, 2011 12:40 am ]
Post subject:  Re: WTF is wrong with the paint?!
hi how many leyers of clear coat has it had or is it just solid colour if so how many coats thanks shaun
Author:  78 Camaro [Sun Oct 09, 2011 11:54 am ]
Post subject:  Re: WTF is wrong with the paint?!
Hey Shaun,

It's 2pack single stage Nexus Autocolour high gloss (PPG brand), with no clear coat. It was 4 or 5 coats laid down every 30 minutes or so. The roof was given a full spray; primer, then top coat (pic of the area primed below) and the subsequent top coats were from the same paint tin and mixed and strained before they went into the gun. I just can't seem to understand why there are these dark borders when i'm breaking through the layers. am i even breaking through the layers? so confused :shock: ! thanks!

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Author:  neil.w [Mon Oct 10, 2011 12:17 am ]
Post subject:  Re: WTF is wrong with the paint?!
Hi it certainly looks like you are cutting through layers of paint did you spray the paint to the correct flash of time between coats its possible that you have left it a bit to long before recoating ,so instead of the paint being sprayed in however many coats and flowing into one solid colour it looks (to me ) as if the paint has gone off in between coats hence the clouding marks you are seeing.The flash off time can vary depending on temp (if it verry hot or cold or also damp humid ect )it seem to me that 30 min flash off seems to long i would have thought 10 /15 would have been plenty,hope this helps and you can make sense of what i have said ? Cheers Neil . PS some of the guys on here realy know there stuff so possibley agree/disagree. :thumbup:
Author:  78 Camaro [Mon Oct 10, 2011 1:21 am ]
Post subject:  Re: WTF is wrong with the paint?!
Hey Neil,
Thanks for you advice, you may be right! I worked a little bit more on that area earlier and cut into the primer, so definitely each of those contour regions were showing a layer - 5 in total. so that cloudiness is most likely down to the paint application then? I cut back the driver quarter panel today and that was fine, so that maybe because the car was sprayed this time last year when it was about 17 degrees celsius in the garage. I painted the whole car (except the bumpers) with 4 /5 coats and by the time 1 coat was done, i would already be starting the 2nd as it took about that much time to get round everything and reload the gun, which took about 15 minutes. I stayed in the garage all day without taking a break from the painting and slept like a baby that night!

The roof was done at the same time last year, but then due to the sunroof delete i had to re-do it and reprime etc. The whole roof (and bumpers) were done about 2 months ago in 30 degrees celsius. I would use the guns worth of paint to do the roof and door (passenger door needed to be redone) and then i would do the bumpers, then leave, get fresh air and come back and restart. Did this 5 times. So perhaps leaving the garage for a break each time meant the flash off time was too great? would applying a 2nd coat too late mean that the pigments seperate or something?

I'd really like to understand what went wrong as a respray is on the cards, so i want to not make the mistake again. Thinking ahead, can i respray on 1000 grit scratches?

Thanks!
Author:  70 z28 [Mon Oct 10, 2011 11:50 pm ]
Post subject:  Re: WTF is wrong with the paint?!
hi ye what neil says is right a think it was left to long between coats and me personaly i would start the flating with 1500 not a 1000 but on the good side yes you can paint over 1000 it will be fine thanks shaun :thumbup:
Author:  Rocky [Tue Oct 11, 2011 10:05 pm ]
Post subject:  Re: WTF is wrong with the paint?!
Seems too long between coats but normally unless the paint is dry it shouldnt affect it that much. Are you reducing the paint at all? Depending on the gun finish 1500 grit should be fine but obviously does depend on finish, If we do a show finish we normally start with 800,1200,1500,2000,2500 then polish.
Author:  78 Camaro [Tue Oct 11, 2011 10:39 pm ]
Post subject:  Re: WTF is wrong with the paint?!
Cheers Rocky!

Ye, so it must be due to too long of a flash time, i think taking a breather in the house was a bad idea. f*k. I must say, i had to work the 1,000 grit to cut through the orange peel on the quarter panel - which was done last year, so maybe that's pretty hardened up. Do you think i've cut too far with 1,000 then? - i did 4 layers, maybe 5 on the whole car. 5 on the roof. I'm worried about breaking into the primer from the paint job of the car done last year, should i be?. Should i skip the 1200 grit and jump straight to 1500 on this quarter panel? then for the rest of the car start at 1,200? (pic below of quarter panel and roof after 1,000 grit and about 8 hours (4 hours per panel - shows either the hard paint or my lack of skill ;) ).

As for the roof then, I have to respray for sure, just need another litre of paint as i have the hardener and reducer already. I use about 1 part thinner to 3 parts paint, so about 30%? thinking i should bump this up to maybe 40%? flash off time of 15 mins max? Sorry for all the questions, i appreciate the advice. As soon as i saw that paint failure i nearly felt like giving up and thinking that this will never end. What's the opinion on the quarter panel i've done with 1,000 - maybe recoat that a few times and start over?

Oh, so the plan for cut n buff is 1200 on a rubber block, 1500 on a soft block, 2000 by palm of hand, 2500 by palm of hand. Farecla G4 liquid compound by machine, Farecla G10 finishing glaze by machine, carnuba wax by hand.

Good / bad / stupid?

Thanks!

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Author:  neil.w [Wed Oct 12, 2011 12:10 am ]
Post subject:  Re: WTF is wrong with the paint?!
Hi i have just PM you did you get it ???
Author:  78 Camaro [Wed Oct 12, 2011 12:24 am ]
Post subject:  Re: WTF is wrong with the paint?!
Nice one thanks, just got it :) just replied too, hope that's ok :)
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