Hello, I'm new here but not new to guns. I have ceracoated several of my project guns including a ptr receiver hk 91, a 1919 for my friend and several pistols. I also did a mini 14 bullpup with hydrodip to try that process. I also have rust blued several guns to try that process out. You can go to the ceracoat website to check out the colors and they also recommend the process that has the best results on all surfaces to see the limitations. basically the short story is the surface needs to be pre heated to get the oils out of the crevases on the metal parts and then cleaned some more then glass beaded to rough up the surface just like any coating put on metal or any surface for that matter. magpul parts can be done at a lower temperature but the time frame is longer to get the coating to cure. I personally have never tried to do wood as that was never a thing I thought I would like. I like wood to be wood. I have glass beaded plastic at a lower air pressure to get the desired surface texture I wanted and also for the adhesion properties. I like ceracoat, I almost perfectly matched the hk color of the Portuguese parts kit I had, sort of a cosmoline parkerized color.