I am using concept urethane for my top coat but am unclear about sealers and primers. On the bare metal I was going to seal with dp40lf. Then spray k36 primer surfacer as many time as needed, reseal with the dp and then color. On the body (fiberglass) I was going to start with k36 ,again as much as needed, seal with dp then color. I have two questions:

1. The k36 product sheet states that it can be used as a sealer as well as a primer surfacer depending on the additives used, so is it necessary to use the dp sealer or should I use the k36 for everything and mix accordingly?

2. Should I clear coat. It's a solid color, no metalic. I will be color sanding as I want a glass smooth finish. I also noticed the product sheet for the concept gives the option of adding the clear in the last coat. Which, option if any, would be better?

With the price of paint I don't want to buy something I don't need but at the same time don't mind paying for it if it's needed. Thanks.