Primer Colors

Machspeed

Member
Forgive me if I'm over looking it, but I'm not finding exactly what I'm looking for. I spoke with an individual a few weeks ago whom advised application of different primer colors to aid in the blocking process. If you know the color of the primer, you know how far you went in your blocking/sanding. Makes sense, I think. Also, I know their is something in picking primer colors in regards to basecoat colors.

So here is my deal..... my car is primered in gray epoxy. I did this several months ago, right after media blasting and have not touched it since. I have some metal work and filler work to do. I'm going to have to sand that initial coat of epoxy and apply another coat. I need to order some more epoxy and was thinking I would order black epoxy for whole exterior of car. Engine bay is black and thinking I may leave it in black epoxy. I will spray polyester in gray as well as 2K in gray and seal with SPI epoxy, in gray. My car is as in my avatar, Gulfstream Aqua basecoat. Am I making a mountain out of a molehill here in regards to the primer colors? What is the rule for the underlying basecoat primer? What would you advise?

Thanks!
 
I do black epoxy and gray primer. You can see epoxy before you hit bare metal... no reason you couldn't do the opposite. it is nice to know when you are at the last layer and can stop in that area. Your plan of switching to black and going gray after that is a great idea.
 
A lot depends on the effect you are trying to achieve. I am not a pro so will defer to those who are to correct me if needed.

Spray out cards were and are used to determine full coverage or "true color" of the base being used. These are black and white squares on a card that you spray your mixed base/color coat over counting the number of coats it takes until you cannot see a difference in the color over squares.

Since some paints are more transparent than others they could take 6 or more coats, while darker colors may cover in 2 coats.

When spraying say a red base coat, you will find it has more brightness to it or "pop" if painted over a white sealer coat and not taken to full coverage.

Now some of the newer paints codes are combinations of a particular shade of primer and a color coat. Others are a tri-stage where you apply two different color coats and then your clear.
This truck is an example of that, the first stage was a very dark green and the second had a mixture of pearl and pigment:
Hood Installed.JPG

Same truck when using the flash on the camera would appear blue:
Step Right Rear Flash.JPG


Of course pearls and candies are in this category as well and there are some many variations and combinations it can make your head swim.
 
Thanks fellas, appreciate your continued input. 68, that truck is gorgeous, you paint that?

As I get closer to my own paint project, I've been asking a ton of questions. I've even PM'd several of you. I've been here since 2013 and I try to do the research, but don't always find what I'm looking for, thus my questions. That said, in all my time on various forums, I can't say I've ever met a more generous and gracious bunch of individuals. Never once have I been chastised for asking a question. Never have I felt offended or the object of ridicule. And, I can't say I've ever seen it here either. This is a heartfelt thank you to the bunch of you. I do appreciate you and the time you given me.

Best Regards,

John
 
'68 is too modest, he does nice work.:) Personally I've done it both ways, two different colors, and one single color of primer. One thing I don't like about using two (usually for me gray and black) is that because I use a guide coat when doing my blocking over gray for instance, the darkness of the guide coat mixes with the black undercoat and makes it harder to tell where your lows actually are. You adjust after a while but it is definitely different than if you only used grey then guide coated.

As for the final color and how undercoats influence them, this is a bigger issue if you were blending into an existing finish. Complete refinish, main thing to keep in mind is that your final coat or sealer coat should be compatible with the color coat. No black sealer for a red for example. Yellows and light, brite reds like a white sealer, blacks dark grey can use a seal coat to the dark end of the spectrum. Most colors respond well (including yours Mach) to a medium gray. Either the SPI epoxy mixed as a sealer or the SPI gray urethane sealer would be a good choice color wise for what you are doing. Just be sure to get complete true coverage on your sealer. Sometimes that may mean 2 coats. Mixed 1:1:20% (epoxy) or 1:1:25% (epoxy) would give good coverage in one coat. If you mix 1:1:50% (epoxy) your undercoat (surface) should already be one color with no sand through. Otherwise 1:1:25% (epoxy) would be a better choice.
 
I really liked black epoxy for everything where epoxy was needed before sealer. I've only done one job but I really liked having black down as a guide between layers and as an indicator to stop and not hit metal.

One more reason I liked to have black on hand was to use it on all the miscellaneous brackets or parts, in my eyes it was the ultimate product to use that looked good and protected in one step. It seemed like these odd pieces never stopped needing to be dealt with and using just one product on them was a huge benefit.

Then for sealer I kept gray epoxy on hand. The poly primer and Spi 2k Regular build were both gray as well.
 
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