Please school me on basecoats and sub bases


Promoted Users
The time has come to pick a color for my '70 Cutlass and I'm lost in which color needs to be sprayed over what.
I think I understand from reading on here that light colors/light sealer, dark color/ dark sealer. After that I get lost in silver sub bases, tinted sealer ect.
I'm wanting a metallic red, blue or green. The car will get driven so a thousand point judged finish isn't required but of course I want it to look good.

As recommended here on the forum, Motobase will be my first choice.
It seems like any of the colors I have picked become complicated in the regard of sub bases/under bases and I've gotten conflicting requirements for the under base even within the same supplier.
Case in point is the color, Porsche "Sail Blue". (32B M5R D2)

"Naw, just shoot it over a light gray primer". (Diamont) < expensive!

"It's calling for a silver under base", eight months later, "it shows it requires a blue under base" and this was from the same respected supplier. The blue under base almost doubled the price. (Motobase)

As stated earlier a perfect show quality finish isn't mandatory.
That being said, can a light gray epoxy sealer do in place of silver under base or will it be so noticeable I'll be kicking myself?
I'm not trying to cheap out, I just want to simplify things.

For you experienced guys this stuff is probably second nature,, for me not so much.
Is there some way to research these requirements or is this information proprietary to the vendor?
I'd like to be armed with a little knowledge so I'm not such a PITA to the vendor.
If the color you choose is a tri-stage, there will be 2 base coats to apply. The first one will be the ground color, the second will often contain pearls, metallics and special contents to produce the finished color.

Yes, they are very expensive but they look nice and that it was draws you to them.

I am not a professional by any means and have painted just two vehicles with tri-stage paint. One was a van with a white ground coat and a golden pearl top coat. The other was a '55 Chevy in Subaru Blue Spruce Pearl.

If you are shooting a regular basecoat/clearcoat job. I can tell you that Motobase covers very well and if you shoot 3 coats of color it won't matter what color your sealer is. Just be sure the vehicle is a consistent color. This is often referred to as achieving "true color."

Imagine using a black and white spray out card. You would apply enough coats of color so that whether it was over a white or black square, you couldn't see any difference.


Trying to be the best me, I can be
99.9% of Metallics don't require a ground coat. Only candy's and pearls will have a ground coat. If it requires a ground coat it is a 3 stage color. Similar to a candy but in all likelihood not a true candy. OEM colors are designed to be able to be repaired and you can't repair a candy. So what they are saying to you is that the color requires a ground coat, then the midcoat. Silver or blue would work for the ground coat. Blue probably achieves "coverage" quicker. Or allows the mid coat to achieve coverage quicker.

How much experience do you have spraying? This is a harder color to spray than a conventional metallic. Something you might want to consider.

Maybe Crash or one of the guys with access to a color formulas would be able to clarify and tell you what is needed. I no longer do so I can't look up the code,


Promoted Users
I swear these manufacturers are "requiring" a groundcoat color to sell more paint. I had a Nissan color that said it was a 3 stage, but the groundcoat was a medium solid gray. To me, that is not a 3-stage color, it is a rip off. All the color and pearl was in the 'midcoat". It was pretty transparent, but not any worse than most metallic reds.


Promoted Users
Thank you gentlemen!
In the preliminary research for a color I was getting the impression that almost all metallic's required a specific color ground coat and that's where my confusion was. As Mr. 68 said, I was drawn to some colors because they just look so good.
If you are shooting a regular basecoat/clearcoat job. I can tell you that Motobase covers very well and if you shoot 3 coats of color it won't matter what color your sealer is. Just be sure the vehicle is a consistent color.
This ^ is what I needed to hear.
How much experience do you have spraying?
That's easy, very little :D
I've sprayed the epoxy and 2K primer with decent results. I also sprayed the underside and some other "non critical" stuff with black SPI S/S, again, decent results. Then it was time to man up and try spraying a door,, it was a disaster.
As the saying goes, "a man needs to know his limitations". I'm embracing that statement and farming out the bc/cc work.

I'd like to thank everyone again for clearing things up. K. Lee