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.

Thanks for the add. Just found the YT channel and have been watching some videos. They have been a great resource and picked up a few tricks. This part is the trunk lid and you can see stripes on camera but not with the naked eye. Whats up with that?

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

@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.

We all know what can happen if we use a reducer that is too fast for our environment. It sets up too fast, the base doesn't have time to flow out, blah-blah-blah. But are there any detriments to the base coat for using too slow a reducer? I'm not talking about bugs flying in, or dust having a chance to settle in, or a boss saying, "Get that *&^%$#@ car out of the booth!" I'm curious about the base coat itself. Assume "perfect" conditions. I'm in a hermetically-sealed spray booth, held at a constant 75*F. No dust, no hairs, etc. Just me, my paint gun, my base coat, and a reducer for an 85*F setting. In this environment, is there anything "bad" about using a slow reducer?