David is joined by John Greene of FL Sales Inc. to learn how foundries work.
About this segment of Blackbird TV
Recorded: September 28, 2020
Published: January 19, 2021
John Greene from FL Sales in Cleveland, Ohio. John is the foundry guy in our world, and one of the more knowledgeable people in the US, possibly the world, in used foundry equipment, and nobody really knows what happens inside a foundry. People don’t think about it like machine tools, there’s how many machine tool dealers and people out there that cut metal? But there’s so many fewer industries that actually pour metal, and do castings. Walk us through the process real quick. How does a foundry work? Well it’s really relatively simple. You’re taking basically scrap metal or a virgin metal—and that can be anything from iron to steel to aluminum to brass to bronze to kerdzite (?) —which is basically lead any type of metal and you melt it in a form or furnace, whether it be induction arc gas fire, you know blast furnace, and then you pour it into a mold of some sort and make a casting and probably the most recognizable are manhole covers. They’re all gas covering boundary or an engine block engine blocks are all cast in a foundry, golf club heads are all cast in a foundry, so those are just three examples of what what a foundry does. They’re just a lot of different methods to do this, but if you look back, I’ve done some talks where we’ve looked at historically foundry is one of the oldest industries in the world and it just makes me think about my experience in foundries is that they’re all dark they’re all they’re all dirty and they’re all old. Is that true? Not at all. If you look at what’s called an investment foundry, where they’re making golf clubs or they’re making aerospace parts, you could almost eat off the floors, they’re that clean. You have to remember, coins are typically… you melt their jewelry, you’re melting gold to form it into a form, that’s that’s really a foundry, also. Wow that’s a good point. Yeah so realistically most of the iron steel the big foundries where they’re making automotive parts they’re not the cleanest in the world but you’re dealing with sand and hot metal and you know it’s it’s tough to keep them clean. Walk me through the process on how you get from an idea to a finished part, and I know that there’s so many nuances to this, if you could generalize how it works, how do you actually get the image in the sand that you then pour your stuff into? Well they have modeling software now that will model and actually in 3D printing also is becoming the new thing where they’re actually printing molds with 3D. Wow. This is not for high production this is for onesie twosies type of scenarios, but you know, you have machines that’ll make one mold an hour you have machines that’ll make 500 to 2000, well 500 molds an hour, but in each mold is what they call, they have multiple parts in it, so you might have five or ten parts in that one mold so these are making twenty five hundred to three thousand pieces per hour, mostly automotive high production foundries is it always. Sand. No sand is is probably the oldest basically in a foundry, it’s sand water and clay, and what you do is you mix the three into certain proportions and then you press it together which will form a mold with a pattern in it that does an impression on what they call the cope is the top and the bottom is the drag then you put those two together and then you pour your molten metal into it that’s the basis of foundries sand and it seems so simple when you explain it that way and it really isn’t is it it isn’t it isn’t, there’s a lot of there’s a lot of things that go into making the mold. You have to look at venting you have to look at permeability you have to look at gas escape, because obviously you’re pouring this metal into a void and it you know when you pour it in there’s impurities you have to take get rid of you have gas that goes through the sand it has to be the certain amount of pressure on the sand where the gas will stay in and create holes in your in your casting so there’s a lot of variables involved in this and it takes a lot of a lot of testing, if you will, in order to get it right. So a weekend warrior might have a Bridgeport mill in their garage, and they might turn parts and do some fun projects. You ever seen anybody with a home foundry before, other than in the jewelry space? On YouTube you can see them, they’re very very primitive, let’s just put it that way. John Greene, FL Sales, Cleveland, Ohio. Thanks for your time this morning. Thank you, David. Appreciate it.