I really have to disagree with the above although it is in part correct. First of all on a sandblasted surface there is no problem or should there be laying your epoxy down. Two wet coats with proper flash times inbetween coats. The epoxy is the best for adhesion and for sealing the metal to protect it from moisture. It can sit on there for years and will not have an issue with rust. When you are ready to start puting on your filler and you have gone past the recoat window which in a lot of cases is 7 days you just scuff and reshoot one wet coat of epoxy and you are good to go.Now you can put your filler on,2K urethane primer or polyester primer on for blocking and filling. I use the epoxy with about an ounce per quart for a sealer. Epoxy is more chip resistant and your gloss retension is by far greater.I will also add that some of the most expensive cars out there are being done with epoxy only. Using a high end epoxy all the way thru and leaving enough cure time ensures that you will have no shrinkage issues and you are not putting on 3 or 4 diff products before the base and clear. Tech manuals guys read the tech manuals. Here's a good rule of thumb if you get a project and it just has primer on it and you don't know what it is. After the primer is cured take a cloth and put some laquer thinners on it and wipe a spot. If it comes off then whats ever on it should come off and reshoot.
