Recently, I sprayed the inside of the doors and underside of the hood of my 1986 F150 project truck. It's shadow blue metallic, ford paint code 7B. Back in 2013, I took it to a guy who was going to paint it for me, but he wound not being able to finish the project. I had forgotten that he had purchased paint for the project, and after 13 years, I had forgotten about it, too. It's been in a climate controlled environment since the truck came home, back in 2014. Recently, in preparation for paint the truck myself, I purchased 2 gallons of paint and reducer (same brand as before) and sprayed the underside of the hood and inside of the doors. I know it's just paint, but I was overthinking, and wondered if the older paint was still any good if I ran short, so I put it on the paint shaker for a while and then popped the clips off and opened the first can. There was no sludge in the bottom, so this morning, I sprayed a test panel with the same black sealer as the doors and hood, and then a couple coats of clear. Soooo.... My question for the group, should I mix the 2 older gallons with the 2 newer gallons, or just a couple quarts of older paint with the new paint to make sure I have plenty in case of having to respray something? Would the color change between the inside of the doors and the rest of the truck be noticeable enough to require those to be scuffed and resprayed? I am going to have to fix a screwup on one door anyway, so respraying it wouldn't be any more trouble. What do you guys think? Opinions, advice, suggestions welcome.

Anyone have experience with this Primer? It's supposedly a hybrid Epoxy Polyester primer. Before joining Make it Match, I purchased a gallon of this stuff for my current build (Fiberglass body dune buggy). I just read through the classroom section on primers and learned that Polyester may not be the best primer to use on Fiberglass. Looking at the TDS, it does include Fiberglass in the substrates its suitable for. Would love to know your thoughts @Aaron Jokela and I apologize for the number of questions lately. Seems that every Saturday I have other commitments that I can't join the weekly call. BTW TDS sheet link is here

My project truck, El Guapo, is a 1986 F150 that was started back in 2010 and has been in pieces for the last 16 yrs. I took it to a guy who was going to paint it, but things happened, and after it was stripped and sprayed with primer, he moved back to California. I was left with a truck in primer, and no good way to finish it. That was 2014. Fast forward 12 yrs and I have it ready for paint. I built a paint booth and I'm now ready to get it done. A couple days ago, I finished the interior with epoxy and a couple coats of a single stage hot rod black. The next day, I did the inside of the cowl, hit it with seam sealer, and a couple coats of hot rod black. This morning, I sprayed the underside of the hood and the inside of the doors with black SPI Epoxy sealer followed by Tamco Shadow blue metallic (code 7B) and Tamco clearcoat. It's not perfect, but it came out pretty decent, and for my first attempt at painting a vehicle, I'll take it.

@Aaron Jokela I just finished reading in the classroom the section on grit guide for filler. At the end of the section you have outlined steps and grits for various stages and I wanted a little clarification. I copied this directly from the text on the page so I wouldn’t get it wrong. Metal Prep for Epoxy 1. Media Blast: Glass bead or similar. 2. Cleaning: Red Scotch Brite with metal cleaner (USC 1240-1 or UPOL 2002 or Glasurit 360-4 or similar). 3. 150 Grit: D/A. 4. 80 Grit: D/A. My assumption is that the numbers are the order in which you work through the process and I get why you’d start with media blasting, but why would you use a 150 grit in step 3 and follow that with and 80 grit in step 4. That is contrary to everything that was discussed about sanding fillers directly above.

Currently working on a fiberglass bodied dune buggy. Other than the original gel coat, the body has been painted once around 2016. That paint consisted of a layer of primer (definitely not a high build) and a base color + Clear coat. I've started the bodywork, correcting the previous repairs that used a regular body filler rather than actually repairing fiberglass and using a body filler made for fiberglass. The areas that need repair get taken down all the way to bare fiberglass. My question is how far down to I need to sand the other areas. I know that there's no way to see all of the potential problems without removing the latest respray, but can I stop at the original gel coat layer or do I need to strip EVERYTHING down to the bare fiberglass? My original thought was that I'd take it down to the gel coat, cover with an epoxy primer and follow that a high build primer to block it? While I don't want to waste time sanding if it isn't needed, it would be way worse to waste the sanding time, the materials cost, AND additional time to re sand because of a skipped step that causes an issue. Any guidance greatly appreciated.