I mainly came on here to find out if its possible to use graphite molds for casting iron. I'm looking at making several hundred track links for a tank project. Being able to reuse a mold to cast those track links would be much mor convenient than setting up a new sand mold every time.
How large are the track links?? Have a picture? I was thinking of a project from awile back that would have needed 600+ tank treads and had plans on casting them in aluminum in a cast iron mold..
Pretty big track all things considered.. You could probably use a graphite mold, but I would think that it would wear pretty quickly changing the part dimensions over the run. Might be better off using a resin bonded sand in a snap flask to produce multiple molds from the pattern, then just glue the mold halves together and pour frameless. Then you get to drill all the holes for the link pins....no joy there!!
It should, but I'm not certain about its longevity. I think the iron will pretty quickly erode the surface.
Thank you very much, I will definitely look into the possibility of using a graphite mold. The project has not yet been completely scaled in CAD, so its possible the tracks will come out smaller.
Welcome! Sounds like an interesting project, whichever route you decide to go, we look forward to seeing it.
Welcome Raymond, What part of NY are you from? I'm south of Buffalo. I'm thinking about the bigger foundry picture for your project, meaning, consider the type of mold you use, the volume and size of the parts you need, and how you're melting and pouring the iron. The time and effort to heat a furnace to pour 1 mold a couple hundred times doesn't really work. Even one with say 4 or 6 cavities (bring your money) might be a stretch. But making a matchplate pattern 2 or 4-on to be molded in greensand and poured either at home or at a commercial foundry might be a better fit. That way you can have as many molds as your furnace will accommodate. Any way you slice it this is a big job and a lot of work, especially for a backyarder. Pete
Welcome Raymond, If you're interested in building a home foundry you're in the right place. 100 iron castings for your first casting project would certainly be ambitious. I must say, if I wanted 100 of any iron casting that size, I'd probably be more inclined to make pattern, perhaps cast a few proof parts to bug out tooling, and farm out the production to a commercial foundry. Not saying it can't be done but it'll take a substantial commitment and literally ton of molten iron....but I'd like to see it done. Best, Kelly
For a project this size, I am thinking green sand, cores for the pin holes, a small cupola, 3 guys running it, and 5 weekends pouring 10 links Sat and 10 Sunday into molds made Thursday and Friday. And 3 or 4 weekends learning how to run it (if lucky). A typical home furnace simply wont hold up to the volume and heat duration needed. It could be used but would have to be rebuilt a couple times likely and could typically only produce a 50 to 60 pound link per melt. A cupola on the other hand would be a hoot and vastly faster. Big learning curve either way. Muller to be made. Handling setup for 300 pound molds. Lifting gear for crucible, skimmers, patterns... Yup, ambitious, but a worthy endeavor. It would be great to see it come together. Denis
Welcome to the forum. Coincidentally I also wanted to cast tank treads, which is what brought me into the home foundry world, nearly 2 decades ago. My project never panned out but my forays into casting have worked out in the long term.
BTW, if these are to be functional treads, I would think casting them as ductile iron would make them a lot tougher. Denis
I am not sure a graphite mold will have the throughput rate you need to do this in a reasonably timely manner unless it is multiple cavity. I think it would last, but a am new to this. Normaly the forum recommends against cupola furnaces because they are set to pour many batches on a short cadence and must be fed continuously. That is what you need for this project. Start with a conventional furnace to work the bugs out of the prototype then move to a cupola for production quantities. Denis number sound reasonable.
Ductile iron would be a necessity. Someone brought one into the iron foundry once, it was indeed ductile iron. Grey iron treads would break apart