The Kneeslider

Doers Builders and Positive People

Build Your Own Foundry

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Cast Metal with your own charcoal foundryThose gorgeous wooden casting patterns Aniket made for the upcoming 1000cc Musket really bring back memories from the past. Way back in time, 1970 to be exact, I spent a few weeks in the summer, working in a brass foundry, that was about all of the time I was willing to devote to getting covered in black sand every day, but it was a fascinating place. You could see the entire process from molten metal to finished brass fittings and jobs like those really grow your understanding of how common objects in this world are manufactured. It’s one of the most basic industrial processes.

These days, you don’t have to work in a foundry to learn about the process or cast your own metal parts, and I’m not talking about making jewelry or art, either, I mean making truly functional metal castings for use in machinery. There’s a fairly active group of folks casting metal as a hobby, and for those of you who truly love machinery, this might be something to add to your skill set.

Back in 1980, David Gingery wrote a now famous series of little books showing you how to build a machine shop, starting by creating a charcoal foundry in Book 1, then using the foundry to cast the pieces necessary to build a metal lathe with a 7 inch swing and 12 inches between centers, then a shaper, a milling machine, a drill press, a dividing head and finally a sheet metal brake. Hand tools and a 3/8″ drill are all that’s necessary to get things started, the lathe is used to machine parts once it’s built, even some of the parts to complete itself. I don’t know of many instances of all of the tools in the book series being built by readers, but here’s one fellow’s experience building the lathe.

A comment in the previous article, points to Kevin Cameron’s interesting article about casting in the February Cycle World, noting numerous difficulties encountered while casting engine parts. Mentioned in the article is a book, Castings, by John Campbell, which takes an in depth look at the process, but you don’t have to get into that much technical detail to learn enough to try your own hand at it.

Most of you may not have any interest in these early stages of the building process, but judging from comments, it sounds like a few of you already do a bit of metal casting. It’s a skill more people should be aware of and something some young guys would probably find challenging and fun, what young boy wouldn’t want to see hot molten puddles of metal? Kids really do enjoy learning if you treat them like adults and give them a chance to get involved in something substantial. If you plan to give this a try, make sure you get some young people involved and tell us how it turned out. Who knows, maybe you’ll want to follow in Aniket’s footsteps, designing and building your own engine, or build one like John TangerÃ¥s and his T900. If you do, be sure to write in with lots of photos.

Comments

  1. I was inspired by David Gingery several years ago and I failed at making my own green sand to get good results. However I have had good luck with the lost foam method and I have since made allot of parts . I like love the way the old cast parts look you can see that they are made by an engineering artist and craftsman not just a engineer. Take a close look at a Crocker for example.
    Its amazing the think casting has been around since the bronze age and there is still much to learn.

  2. Great idea!
    When I was working at Flyrite the owner encouraged us to make various parts this way, so we bought a small propane furnace, A356 ingots, safety gear, oil sand and made a casting box. I CNC machined some Renshape casting patterns for a points cover and tried it out..
    It worked great! and was a lot easier than I thought.
    I think the hardest part was designing the patterns with decent draft, gates and sprues.
    Post machining without heat treating is a sinch with carbide cutters, though heat treating is recomended.
    Having a home foundry is on my short list now!

  3. I built a tilt-smelter from off-cuts of 409 S/S, fire brick, refractory cement, rock wool, and other bits and bobs. The hardest part to build was the burner. I fed the fuel at about 50 psi (metered with a re-purposed mig-welder gas regulator) thru a 1/16 orifice (drilled out mig tip)…into a 1.5 inch venturi…boosted by an electric blower feeding air at maybe 150 cfm. I would lite the 15 inch long x 2 inch dia burner tube (with 45 degree angled nozzle), then insert it into a bayonet mounting along-side the crucible. I never measured the thrust but it was basically a propane jet that could fry mosquitoes twenty feet away.

    ps. Melting metal with your kids is a really fun “bronze-age” thing to do. It’s like being fire-Gods for an afternoon.

  4. After dropping out of a pre-med program in the ’70’s a friend urged me to get back to school by taking a foundry class. Having never been exposed to industrial arts I was extremely drawn to the immediacy of the casting process. In green sand casting even the pattern can be disposed with by hand carving the mold. Instant idea to object! I proceeded to complete the entire Machine Tools Technology program at my school, but time and again I have returned to the foundry at multiple departments and institutions.
    I would like to note though, that as intellectually engaging as the process is, the physical experience of pouring substantial castings is very much on par with skillfully piloting a motorcycle. Careful planning, preparation, steady nerves, luck and good safety gear will make all the difference. The brilliant heat and plasma effects (pour at night) are as awe inspiring as any canyon road. And the handles of the pouring shank of course will feel right at home for any cyclist. The sound of my blast furnace rumbling in my shop will raise my pulse as certainly as the rumble of a freshly assembled high performance engine.

    • You brought a smile to my face.

      If you approach a task with the right mindset, the rewards are sometimes all out of proportion to what you might expect.

  6. One of my favorite parts in “Fastest Indian” was the piston casting. I especially dug the way he filed off the casting plug with a big flat file.

    Would love to cast my own stuff, this is the third mention of casting lately. I have an instructables newsletter with it, James May’s Man Lab Season 2 (BBC) has him casting aluminum, and now this post.

    Definitely a skill that could be very useful.

    • I well remember an article about Burt Monroe in either “Cycle” or “Cycle World” where he described making new pistons in the sand by wiggling them about a bit so that the new piston would be somewhat larger. Along with Allen Millyard, Burt was one of my “motorcycling heros”.

  7. Very enlightening, made my day. The personal value of actually doing, building something yourself can not be rated highly enough. Thanks for the help in lighting the way.

    • The only down side to this phase of project making has been the accumulation of lawn mower carcasses, 4 cylinder engine blocks and all the other assorted scrap that is left over from recovering the AL. Fortunately hauling that scrap off to the recylcer usually at least pays for the gas to haul it.

      Oh, and the 400 sq ft of real estate that is permanently dedicated to firing up a foundry with a crucible that is large enough to swallow an entire 4 cylinder head as well as a smaller parts pouring unit.

      And of course there are the frequent trips to collect used oil from some very friendly resteruant owners for the Babington burner setup. Propane is way too costly for reducing large parts to useful ingots.

      But the gratification that comes from customizing or overhauling a bike is simply magnified a hundred times over when you look at (or know there inside) parts that you truly created from scratch.

  8. If you still want cast metal parts but don’t feel able to devote the time or space to physically casting the metal, making molds for a foundry is still a pretty viable option. Especially if you want something larger than can readily be cast at home. Here in Kansas City there are at least half a dozen foundries that do aluminum, and I know there are bronze foundries as well. I assume there is a place somewhere in town I could get steel cast.

    Though I have access to a CNC router at work, I would love to have a CNC mill at home so I could make my own motorcycle stuff, and patterns to cast for motorcycle parts.

    • I did a project like that once. The foundry guys were very helpful after I discovered that I made a couple of stupid mistakes. It hurts to start cutting into something that you already spent a 100 hours on. I recommend that a would-be pattern-maker spend a bit of time with the particular foundry of choice so that your match-plates work with their flasks, and that you consider the gates and runners.

      • I was fortunate with the foundry that did our project. I had almost no knowledge of sand casting (I had done a little investment casting in college), and they were very helpful in explaining what sort of pattern they needed.

  9. Great article. I build the charcoal foundry in college, and had a lot of fun with it. I got about halfway though the lathe before I abandoned it. I did go on to do a lot of casting and made some pretty intricate castings using laminated stryofoam using the lost-foam method.
    Also used the foundry for some blacksmith work.
    Great little project which shows how to make things happen on your own and not make excuses.

  10. This article really touched a nerve on me. I was pushed into college, only to find myself wanting hands-on jobs instead of the white collar work that my resume and education allowed. After a few years of discontent in an office I started a small electronic motor company, bought a lathe and welder, and started realizing my previous “can’t do” attitude was just learned ignorance. Now I want to build a little foundry, even just for fun and knowledge. If nothing else I can cast some ingots to work with my machines. I still feel like a blue collar man trapped with a white collar education sometimes, but at least I can use hobbies to release my frustrations!

    Kudos to you, Paul, for writing such an important article. I can only hope that our children have the chance to learn basic fabrication skills that are ignored by today’s generation. I have vowed to enable my children with education that values production of physical goods as well as service, as I did not have those opportunities growing up.

  11. I first learned about casting in high-school shop class in the days when new motorcycles leaked oil. It’s a very sensuous, hands-on process of filing the boxes, sifting the sand and tamping it down, then melting the metal (aluminum in our case), putting on the protective gloves, aprons, face shields and greaves, lifting the crucible from the furnace and pouring the shiny metal into the sprue. Popping the part from the mold is exciting and marvelous; just make sure to let those castings cool thoroughly before you try to pick them up bare-handed! Ask mye how I know this!

    Reading Kevin Cameron’s editorial on casting in this month’s CW shows me that the art of casting is ever-evolving and there is still a lot to learn after thousands of years. Properly-cast parts can be as good as injection-molded or machined parts. There’s a lot of science in casting, but it’s still an art. Those patterns for the Musket 1000 are worthy of display in a museum.