Im a rookie myself. This is my first full paint job. Im using all spi products from the metal up. Also just bought a new Tekna copper gun. Shooting spi red over grey epoxy. Painting in pieces in a small garage. I shot the epoxy as a sealer and wet sanded the next day due to it not laying out smooth (completly my fault, after a call to Barry I can lay it down like glass ). I ended up breaking through the epoxy in a few places (edges mostly) into the buff (yellow ) primer. I knew that I was going to shoot 3 coats of spi red so I figured I would be good to go. Well I could still see the yellow under 3 coats of red. I had to really put,it on heavy to make it dissapear. Moved on to doing some smaller pieces. On the cowl panel I had broke through to the buff also. I hosed on 3 coats and thought it was good. Cleared it and it looked fine in the garage. Took it out in the sun and bam there it was. I am pretty sure that I put 3 heavy coats on it as the base dried with a shine like it had clear on it and was very smooth.
Now with all of that being said I am new to all of this and it may just be me. One thing is for sure. From here on out all of my parts will be a solid color before any red paint gets sprayed. In my eyes the sealer color does make a difference in final apperance.