I'm working on casting a single blade throttle body for use with old school style mechanical fuel injection, much like the toilet designs of today. I have a couple questions on the pattern piece. I see in this thread: https://www.jalopyjournal.com/forum...-sand-casting-master-in-your-basement.462249/ That @alchemy has his pattern looking much more refined in terms of paint / finish. In the thread he says he "primes" then uses a "smooth coat of krylon." Are these rattle can deals? Sorry if im paint stupid, I've always just rattle canned my cars flat black or shot a rattle can of this on my parts and then scotch brite / light sand them: Any information on making my part look more refined would be greatly appreciated. I need to make a 3.5" x 6" core. I'm gonna go scavenge a piece of PVC or something with a. 3.5" ID that i could use as a core box. If that doesnt work out I do have a boring head on the mill that would get the job done, but it would probably suck going that in wood. Other option is a hole saw which would leave the hole finish pretty rough and take up a ton of time to smooth out. Any "outside the box" ideas? This is where im at with the pattern right now, its a split casting, i still need to make bosses for the throttle shaft and stop. I need to turn the two split halves of the "core" for the top and bottom to size and glue them on to the larger pattern. I'm thinking I might sandwich them between two smaller solid patterns and they'll hold together on the lathe long enough to get the OD to the right size on the split pattern. As always the answer to "why dont ya buy" or "billet" is "because I can!"