spotfitz Posted February 24, 2005 Share Posted February 24, 2005 Alittle history. I had my '74 painted last year and it has done nothing but sit in the garage since July/August of '04, except a rinse off one day when I was cleaning the garage. I now have what I think is yellowing of the clear, but I'm not sure. Brand of paint and clear unknown. 2 stage paint, artic white(6 coats) with gun metal metalflake in the first coat of clear(6 total clear coats). It has not been color sanded yet. I was present when the same painter had painted other cars and there were no issues that I know of. I was there, in the booth, when mine was shot and after it was pushed out of the booth and onto a trailer and it looked fine. I watched as the cups were thoroughly cleaned and different guns were not used for the paint/clear. Since then my Z has started showing yellow patches. It doesn't appear to be getting worse. Same patches in the same spots. I don't even recall when they first started showing up. I was told it was because of the high output fluoresent(sp?) lights in my garage turning the clear, but I'm certain this is crap because it wouldn't have the patches of yellow on the hood and not on the roof, which is closer to one of the lights. It has yellowing in patches on almost every panel on the car including the engine bay, which was shot at a diferent time. This would leave me to believe it is actually bad paint or possible bleed through of bad body work, but the engine bay didn't get body work and the interior(which didn't get cleared) hasn't had a problem with the yellow patches. There are other spots I know didn't get body work that have patches. All this points to the clear. Is this a good assumption? Of the paint experts on this site, what are your takes on this? I'm really hoping that once it gets color sanded and buffed out(which will be done by the original shop) it will be ok, but I'm hoping someone could give me some advice as to the problem. How does this type of thing happen? Quote Link to comment Share on other sites More sharing options...
smokeshow Posted February 25, 2005 Share Posted February 25, 2005 Do you have any pics? Was there a car cover on the car? Quote Link to comment Share on other sites More sharing options...
spotfitz Posted February 25, 2005 Author Share Posted February 25, 2005 No, never a cover on the car. I can take high res. pics, but of the other pics I have taken(in my album) nothing seems to show up. I'm sure if I put some light to it(which i definitely have and I knew how to use my new 5MP camera properly I could get it to show up). Maybe I'll do that this weekend while I'm crying in the garage! Quote Link to comment Share on other sites More sharing options...
ZR8ED Posted February 25, 2005 Share Posted February 25, 2005 Well I'm no refinish paint expert. Yellowing of clearcoat can come from too much or too little activators. Activated paint that has been too long before being applied. Too much heat. (higher temps, or too long of a bake) Incompatibility of clear/base Paint is old/subjected to air/moisture. (same goes for clearcoat) Activators are old/subjected to air/moisture. Paint not mixed thoroughly (before activators added) or after. Improper flash off times Uh.. I'm sure there are some others I'm missing. I just had this happen at work. Guys were repairing white cars and the clear was turning yellow during or sometimes before baking.. Found out the guys were mixing the clear and activators, and mixing base and their activators, and leaving them in the guns sometimes for 1 week depending on the # of repairs for a particular colour. Then it was not curing proper, so they started adding more activators to the clear.. MESSY. lots of ruined cars.. I had them spray a few panels under my guidance (to recommended specs) and found the colour was bang on. The paint was even from the same gallon can! Mixed fresh! Chemicals can be touchy and unpredictable when mixed incorrectly. Quote Link to comment Share on other sites More sharing options...
spotfitz Posted February 26, 2005 Author Share Posted February 26, 2005 Thanks for the info so far guys. I'm really hoping that it is indeed the clear and can be rectified with color sanding. I've been half tempted to try out the bad areas in the engine bay to see if it will sand out, but after a recent post on this forum I'm not sure I want to attempt it. The frame rail has some bad spots on it, maybe I'll hit that area on the drivers side considering it will be mostly hidden. Any advice for proper procedure other then posted in the other topic would be great. I have up to 2000 wet/dry and even some 4000-6000 for polishing plexiglass if it will do the job. If I can make a plexiglass window from an airplane with knife cuts in it and make it look like new I think I can attempt the frame rail. Prior to painting, the car was all the same color(grey) primer. I did have pictures of just before, during and after the paint job but at the time I didn't have a digital and the developer ruined the instant film, so...I may have some pics of the week before painting. I'll check tomorrow. I'm pretty sure that I can find out the brand paint that was used. Considering the upcharge I received for wanting the interior painted after the first estimate, even though I prepared the interior for them, I would think the paint wasn't anything cheap. If I remember correctly, it was stated something in the neighborhood of $200 per gallon. This also may have been just "upcharge" talk. I am not going to mention the conversation with the owner right now. It isn't proper until I know exactly what he wants to do about the situation, even though he didn't have the best response about the problem. I may swing by the shop and find the paint that was used tomorrow. If not tomorrow I'll have to wait until next weekend. Considering the cost of the paint job and the extent of the assembly so far, I am not looking forward to a repaint if necessary. Anymore advice is very much welcome. Sorry for the long post. This is very upsetting to me considering what this Z means to me. I'm sure you can understand. Quote Link to comment Share on other sites More sharing options...
Nismo280zEd Posted February 28, 2005 Share Posted February 28, 2005 find out the products used, that would be very helpful. Is it just turning yellow or are there small spider cracks or wrinkling in it? -Ed Quote Link to comment Share on other sites More sharing options...
spotfitz Posted March 1, 2005 Author Share Posted March 1, 2005 I helped a friend move all weekend and then Monday I had to take my girlfriend to the doctor. Didn't get any new info on the products yet. There is only yellowing. No cracks to be found. I'm hoping to know more this Friday. I may try to take some pics of some of the patches tonight. Quote Link to comment Share on other sites More sharing options...
spotfitz Posted April 13, 2005 Author Share Posted April 13, 2005 Well, to make a long story short, the color sanding did not take out the yellowing as of yet. My '74 was a tech session for our Z club this last Saturday and the original painter color sanded the top of the fender and part of the top of the car. The yellowing didn't come out with the little bit of color sanding he did. There was still some orange peel to the clear after the buffing so I know there can still be some sanding to be done. He had asked me what primer I used when I was doing the body work before dropping the car off. I said it didn't matter since the hatch, cowl and right door that was on the car now wasn't the parts I originally had on the car before it got painted and those parts now have yellowing to them. The funning thing about this is he pointed out another car he had just painted the engine bay of. Guess what. After putting the clear on the white it started having yellowing issues. What does this tell the powers in the know of paint work? To much hardener? To much "Wet Look"? Quote Link to comment Share on other sites More sharing options...
Guest Magnum Rockwilder Posted April 13, 2005 Share Posted April 13, 2005 It's caused by spraying the clearcoat on before the base has fully flashed, as well as spraying TOO MUCH clearcoat and spraying it too heavy. Some of the chemicals that are trying to evaporate from the basecoat are trapped in the clearcoat, causing it to yellow. There's NO WAY that the base OR clear can properly cure when he sprayed 6 coats of each! Depending on the brand and the solids content, the car should have 2-3 coats of base and 2-3 coats of clear, and none of the coats should have been sprayed before the previous coat had "flashed", or evaporated away the initial stage of reducer. It would take him FOREVER to spray 12 medium/wet coats and allow each one to flash off, so he probably just kept loading the car up with paint until he buried all the orange peel from the previous coats. It can also be caused by peroxide vapors evaporating out of body filler that wasn't primed properly, but you said you did no bodywork on those areas. To put it bluntly: he owes you a paint job... and he needs to stop putting 12 coats on... it makes it LESS durable than a properly applied 4-6 coat job. I'd be willing to bet that the paint starts to flake after the car is on the road for a while. Quote Link to comment Share on other sites More sharing options...
VinhZXT Posted April 14, 2005 Share Posted April 14, 2005 Hi Spot, I'd painted my hood for my Z and when I took it home I saw white haze spots all over the hood sort like clouds. By looking at it I know it is in the clear coat. So I called up my friend who mixed the paint and clear coat for me and found out that he add a little more hardener to make it cures faster because it was cold in the boot. Anyway I had to sand down the whole hood and repaint it and I did it when it was warm outside. Sould like you may have to bring it back for a repaint. Quote Link to comment Share on other sites More sharing options...
spotfitz Posted April 14, 2005 Author Share Posted April 14, 2005 It's caused by spraying the clearcoat on before the base has fully flashed' date=' as well as spraying TOO MUCH clearcoat and spraying it too heavy. Some of the chemicals that are trying to evaporate from the basecoat are trapped in the clearcoat, causing it to yellow. There's NO WAY that the base OR clear can properly cure when he sprayed 6 coats of each! Depending on the brand and the solids content, the car should have 2-3 coats of base and 2-3 coats of clear, and none of the coats should have been sprayed before the previous coat had "flashed", or evaporated away the initial stage of reducer. It would take him FOREVER to spray 12 medium/wet coats and allow each one to flash off, so he probably just kept loading the car up with paint until he buried all the orange peel from the previous coats. It can also be caused by peroxide vapors evaporating out of body filler that wasn't primed properly, but you said you did no bodywork on those areas. To put it bluntly: he owes you a paint job... and he needs to stop putting 12 coats on... it makes it LESS durable than a properly applied 4-6 coat job. I'd be willing to bet that the paint starts to flake after the car is on the road for a while.[/quote'] Now that is some info I wanted to hear, but not really. The sad part is this car won't be on the road anytime soon. Probably will take another year for me to put the rest of it back together. As for the new paint job, he had already stated that it wasn't getting repainted. Lets just say "we'll see". Thanks for the replies. Quote Link to comment Share on other sites More sharing options...
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