Guys, I have an issue. I am painting a black base coat on a vehicle. We are using 100% PPG products so there is no incompatability with products. When I spray the balck base, I get a sheen that looks like a water puddle when you drop a drop of gasoline on it. There are no other obvious paint issues, like fisheye or orange peel present and it all appears, after wet sanding, to have good adhesion. Any ideas???
Sounds like oil in air supply....but then again, I would think it would fisheye.... Does the sheen sand off?
some black bases have an odd sheen to them without the clear gm's typical 8555 black does this in the dupont and nason lines dont know why just always has a wierd blueish purpleish sheen until you shoot the clear over it then it looks normal and is a really deep black
to answer the questions, I am using all the same equipment I have always used. Good moisture trap, NEVER had an inline oiler in my system and never had the problems before. The sheen doesn't seem to sand out until there is some primer showing through. It has good adhesion and no fisheyes. We also took the wheels all the way to clearcoat. The sheen did not disappear with the clearcoat. I am not worried about the wheels though, we have stainless steel simulators for the wheels. My suspicion is that most of this paint was donated to the project by PPG and the store where they are having me pick this up has a guy running it that is not very knowledgeable, and he also treats me like I am robbing him when I show up to pick materials up that were donated. I find it hard to believe he would do it, but maybe he is putting something in my paint that may cause this? I have bought alot of stuff from this guy, as PPG is only picking up the cost of the paint. I am just at a loss, we want this truck under paint soon so I can get the graphics guy up here to do his thing.
As already said, nothin to worry about, its just the nature of the black base. It will go away when you clear it, spray a light dust coat before you clear if it will make you feel better.
I'm not fully understanding the sheen you have going on. It sounds to me like the base is laying out a little satin like, which is ok, but then you say when you clear it the satin doesn't go away? Its clear, it increases the shine?!?!?!?!!? I'm confused.
Have you tried shooting a test panel with clear on top of the base? I know the wheels were cleared. I'd love to see a picture.
any way you can post some pics that would show it? call your local ppg rep. he should be able to help you if he cant resolve this issue over the phone a lot of times they will pay you a visit if they are close to your area
It is not laying down satiny, it is laying down pretty glossy for a base coat. The sheen looks like a rainbow sheen to it. I am going to spray a test panel this weekend, and the PPG rep is working me into his schedule for a visit. It might be shopline, but DBU comes to mind, I will get more info off the can for you. Taking a pic of the sheen is hopeless, it doesn't show up in the pic, but in person, you can't seem to make it disappear. The truck doesn't look black when you are done.
If the paint was free, and doesn't work perfectly, I'd toss it and buy some new stuff. Specially if there is a deadline fast approaching.
Was the humidity high when you painted? I haven't had problems with sweating due to rapid solvent evaporation in a long time, but when I used to shoot laquers , back in the day, black was the worst on humid days. the sweating would look colorful and then cloud up and turn grayish white. The remedy then was to retard the drying time. Use a higher temp, slower reducer. I use PPG products exclusively and I like the DBU formulas. Get a product info. sheet for all the components in your paint system and check to see they are all correct and that you mixed them correct.
This is normal with PPG black basecoat if you spray it a little to wet.Make sure you let flash completely before you clear it.Try not to pound it on so much and wait between coats.Don't blame the supplier it's user error.
Well, I never ruled out user error. I did not just blame the paint or manufacturer, just made some guesses based on the customer service received and the performance of this paint vs the performance of the other paints I have gotten for the project. I did look at the can, and it is Shopline JB paint, which I know is not their "top shelf" paint. I still expect black to be black. I am using midtemp reducer, and as I recall, it was not real humid when I shot it. We will try lighter coats, but I would have expected to at least get a uniform coat on without too much problem, It was just enough to get solid black, but still a bit thin compared to how I shoot single stage paints. I appreciate all the help, and we should get an opportunity within this next week to shoot some to see how it works out. I am mixing it exactly by the paperwork with the use of PPG mix cups.
I was just curious if you poured a lil reducer in a clear plastic cup and looked at it to see if this "rainbow" effect shows up at all. This could be a product that just has a bad ingredient. I work with other paint suppliers and from experience sometimes that "free" material was material that was recalled for different reasons. I don't want to hurt anyones feelings I am just saying it is a possibillity and could be resolved as easy as another gallon of basemaker\stabilizer\reducer whatever they call it.
Just to back up what FunnCar said, I go to a retail store and pick this paint right off the shelf where you would buy it. They are donating it for a community service project I am working on, not just giving my dicards. I did look at the reducer and it is absolutely clear and mixes readily with the paint. I am looking into the slower reducer, even if it were not an issue when I did shoot it, it is way Hotter now and alot of humidity. The product is Shopline JB and the reducer is JR506, which is the mid temp reducer if I am not mistaken.
Just curious as to why you are wet sanding the base coat? You will have poor adheasion by putting clear over sanded base. Always shoot more base ontop of any base that you sanded before clearing.
Well Matt, it did NOT go away when we cleared over it on the wheels. That being said, I have wheel simulators going over them, so not a big deal. I don't have anything to cover the body after I paint so, it is important to get it off of there. I wet sanded the current base coat because the finish was unacceptable to me, and I don't just keep spraying till it is right, I had to remove the "contaminant" before I can spray a new base coat. Finally, I have always heard that you do wet sand the base coat, to get bugs, dirt etc out of the base, so they don't ruin the clear coat. I do not have a professional booth and will not invest in one for the very few times I will be painting. Anytime you sand you create grooves, even if very small, as with wet sanding, and that will HELP the clear adhear, not hinder it.
Give it time to dry between coats, sounds like your too wet and your getting in a hurry. a solid color base will always appear to "look Funny" it will achieve the look your after if you read the can, follow those directions and be patient.
Hey Willy, Oil on water produces a prismatic affect- like a rainbow- Is this what you are talking about?? I painted cars professionally for over ten years- and honestly, I have never seen anything like that. Overall, most paint problems have been solved before the paint is put into the container for you, and you really seldom ever experience anything different than fisheyeing or possibly some "blushing" in a really humid environment. Your problem sounds really weird- and I think it has everyone pretty much stumped. Basecoat can have sheen like that, but it's very subtle and dissapears after you wet it down with clear. If you have some pictures of the problem AFTER it has been cleared, we'd love to see them/
Sorry, not wrong. I don't just give out advice when I don't know what I'm talking about. I have had black look oily and rainbow like before, but in my case it went away when cleared. So I'm not really sure what the problem is he is having with that. However I have been doing this stuff daily for the last 13 years and do know that you do not clear over sanded basecoat. And when nibbing dirt or other trash out of basecoat, only sand in the spots needed instead of just sanding the entire part. As even the next coat of base will not adhear as well to the basecoat you sanded. I have also been through PPG and Sherwin Willams training. Just trying to help, not trying to start up an agrument. If you want to sand base and clear it, thats fine with me.
Affirmative. Basecoat/clearcoat systems have been designed from the very beginning to be applied "wet on wet"- with no sanding in between the basecoat and application of the Clear. --That's pretty much the whole concept behind Bc/Cc.
Do you have an old air compressor? Maybe its blowing oil past the rings. If that were the case, I would think you would have a new batch of fisheyes with every coat. PPG is meant to go on dry. Are you not wanting to clear it? If you want to lay it down wet for a satin look, DuPont is meant to be sprayed wet. Humidity shouldn't be a factor for hazing unless its a cheap grade of basecoat. I use nason on our ARCA cars and it does that. What exactly do you use for a water trap?
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