I just typed most of this out and my iPad died so it going to keep it short. I have a Prerunner I've painted and the silver metallic is darker than the factory paint. In the sun it's a dead on match but the side tones are not. It has a gray base vs a blueish base on the cab. I notice that every guy I know with a prerunner who has had their glass painted has the same result. The glass is always darker. So is this just a common thing? Does paint on glass always come out darker than metal panels?

I sanded the glass with 180 to get the gloss off the gelcoat than shot it with 2k high build primer. I sanded down to 600 and sprayed base than clear. At first I shot Matrix and then Valspar after the first go round didn't give me the match I was looking for. Am I missing something? I I be using a sealer? I'm just looking for a better match. Here's where's I'm at it looks a lot better than when I started but I think it could be better:

Welcome, Ubernoob.... And you now join the ranks of millions of vehicles with mismatched silvers. It is hard enough sometimes to get silver to lay down consistently on metal but when you throw plastics into the mix it is much worse. Just take a look at a lot of cheaper new car bumpers that don't match the car.... You can see this effect even on high end paint jobs with combo steel/ fiberglass hot rods, kit cars, etc. First, it is a textural thing with the substrate material itself. Pour some water on different types of surfaces and watch the reaction. It will "flow" differently depending on what it is poured on.... Now take into account the fact that as you shoot to a fiberglass surface you are generating static electricity, dial in the finely ground lightweight flake material in modern paints and well, gee..... it's little wonder that you have trouble replicating just how that stuff lays down.
To me about the only thing you can do is to start addressing.... step by step corrective measures to at least improve your chances of a successful match. First, off, you do know that you don't just shoot panels, right???? You must overshoot and blend into surrounding panels for color/effects matching. Next, I always make sure that I am trying to replicate the primer base color as close as possible. One thing that I think I am seeing is "mottling" in your basecoat application. That can definitely give you dark shadowing. Another factor to at least reduce in the process is static electricity. Find a nice big bolt on the chassis and run a chain from it to an earth ground on your building. Your main electrical box will have a large ground wire going to a ground rod sunk about 6 to 8 feet straight down. Attach on to that rod. Another measure that I think helps with this is completely wetting out the air in the shop before shooting which has the added advantage of pulling all dust "down." And last but definitely not least....AIRFLOW... if you don't have good airflow when you shoot the metallics like this they will settle back on the existing base color causing a distortion of color. Oh, and you've got to shoot these colors like you are a robot with consistent gun speed, overlapping, etc.
For newbies it is not impossible to get a better match... it's just a lot more difficult than shooting straight colors.

I appreciate the detailed reply you have a good eye -Yes there is mottling. This and the color match is the main reason I'm not blending into the doors. Until I get a nice coat and get the metallics to lay right I'd hate to blend into perfectly good panels.

I'm in Las Vegas. I get shocked turning on and off the lights this place has low humidity and lots of static electricity so that's definitely something to consider. I should be good on the airflow with about 13.5 CFM at 40psi. Im trying to stay pretty consistent I do know that I need a lot better lighting but I'm trying to make due with what I have. im going to be helping a friend this weekend and doing a single stage red hopefully that'll be way easier than metallic.

Vegas.... yeah, I know guys in the wood trades out there and they all have "unique" problems shooting stuff..... Hey, I did confuse you on one thing there... the airflow I am talking about is not for your gun...I'm talking about your booth exhaust or the airflow WHERE you are shooting. If you don't have good airflow over the surface you are shooting the overspray can quickly reattach itself to the coating with disoriented metallic. The exhaust air must be constantly pulling away from those surfaces as you shoot.

DarrelK wrote:Vegas.... yeah, I know guys in the wood trades out there and they all have "unique" problems shooting stuff..... Hey, I did confuse you on one thing there... the airflow I am talking about is not for your gun...I'm talking about your booth exhaust or the airflow WHERE you are shooting. If you don't have good airflow over the surface you are shooting the overspray can quickly reattach itself to the coating with disoriented metallic. The exhaust air must be constantly pulling away from those surfaces as you shoot.

I was thinking about that as well and called the air conditioning guys to come out and turn on the swamp coolers. They shut them down for the winter. With the warehouse doors cracked open it creates a nice vacuum to suck out the air.

With the last set of fenders I painted the swamp coolers were on and there was better ventilation and I didn't have mottling. Unfortunately my front suspension would clear with the fenders and I had to go to a one piece front clip. Any suggestions on how to ground fiberglass that's being painted off the truck?

Okay, a stand alone fiberglass part is a little different. First of all....yeah, get your relative room humidity jacked up to a bare minimum of 50%. Next, don't be tempted to use a compressed air blow off on the piece. That is just going to create more static. Best thing to do is WIPE the piece down with a water based cleaner. PPG and just about anybody else make water based cleaners for prep. or you can make your own with a minimum of 50/50 denatured alcohol/distilled water mix. You can even go as high as 80/20 mix with more alcohol.
And, finally read through some of the discussion on this link....
http://www.chevelles.com/forums/12-body ... tatic.html
And just one final note..... I am not confirming or denying this but....JCClark on here swears by using Endust as a prep. before shooting. Don't laugh.... I checked this out years ago and there is some sound theory behind that stuff since it is not a true polish. The ingredients listed in their MSDS sheet do not appear to be incompatible with a coating process.

All of what Darrel has mentioned is relevant but the biggest single reason is that plastic (including fibreglass) holds heat differently to metal.

Just think, on a hot day the metal feels hotter to the touch than plastic while on a cold day it feels cooler. So, given that most paint on warmer days a metal surface will have absorbed more heat than a plastic one. This affects how the basecoat dries - quicker on the metal, and explains why you have a darker flop on the fibreglass. The paint has dried just that little bit slower and the metallic flakes have sunk deeper in the paint and laid down flatter.

Solution? Lighter coats and maybe a faster reducer. You can also give it one final very light coat to stand the flake up a bit. If I'm painting say a guard and bar at the same time I'll use the second method. Most of the time I can see how the base is drying and can adjust but it can be interesting when you're painting two parts on the car.

It's a bit of a delicate call that has to be made either on experience or having painted some test panels in the same conditions.

Swamp coolers? Same as what we call evaporative coolers? I'd be careful with these. Increasing the humidity can lead to another whole raft of problems.

Yes evaporite coolers. I'm hoping I didn't go the opposite direction that I should have. The paint shop mixed up a new batch of paint and used a slower reducer to give the metallics time to settle. This was to address the mottling issue.

I did read the other post and planned on getting some endust to try.

I've seen different techniques on a final dropcoat. The one that makes the most sense to me is to do the drop coat immediately after the last coat- meaning when the paint is still wet. Thoughts?

Well, I used to always do drop coats however paint technology has been evolving I just haven't seen the need for them in the last 5 years or so. That doesn't mean that it could indeed help you in your situation. And, yeah, I did them just like you said, immediately after the last coat while still somewhat wet.
Hey, NFT5, things must be a little different with you guys down under there.... If I have my shop heat on and normalized for a few days my temp difference between a metal surface and a fiberglass surface doesn't get off much more than a degree or so. I use an industrial laser tracking infra-red reader to take surface temp.s We use it in our wood shops because woods are even more sensitive than anything we shoot. Now I know, that if I was shooting outside or worse had the car outside and moved it in the "heat loads" would definitely be different in the plastic/metal surfaces, well at least until temps. normalized in relation to shop temps.

DarrelK wrote:Hey, NFT5, things must be a little different with you guys down under there....

Yeah, it's a problem having to deal with runs that go up the panel rather than down.

I've never had a laser thermometer but even if I bring a car into the booth with plenty of time for the panel temps to stabilise to that of the booth there are definitely differences that you can see when laying the basecoat on. Lots of jobs I've done doing a bar and guard on the car and you think it's right but, later when you get it outside, there is a difference between the two panels. You say WTF?, same paint, same gun, same time - how can it be different? But it is.

In a case like that I'll do a dropcoat over the plastic panel, but I like to let the previous coat flash off a bit first so that the dropcoat doesn't just melt in to the already wet surface, making just a thicker coat and exacerbating the problem, rather than correcting it.