Have we discussed foundries?

4cylndrfury wrote: Hal, I love that grinder - great job! They dont build em like they used to

In Metals 1 class in high school I learned that we would make our tools that we will use as machinists.

At 14 years of age I was blown away that we could do that - what a profound statement. I still use some of them 40 years later.

I signed up for alloy avenue, did more reading on the forum, and wow am I impressed. Some of those guys are incredible!

I got thinking about fuel, has anyone messed around with accelerants to get more heat? Long story time: I used to be a graduate student studying archaeology in North America. One of my fellow grad students was studying native made copper. In Central America, there were some bells cast in copper. Not many, but enough to spread around a bit. As part of an experimental archaeology project (just to see if it was possible to melt copper in an open wood fire), he and some other students used something, bone I think, prepared in a specific way added to a fire to increase the temperature. I don't know if they reached copper melting levels in that experiment. They did have some heat sensing equipment, but the fire got hot enough to melt the e36m3 out of the thermocouple and the meter it was plugged into so they were not able to get a clear reading. The geology department (who owned this stuff they were borrowing) got SUPER pissed, but aparently it wasn't the first time an archaeology student melted their equipment. I'm thinking I might be able to crank up the heat on these briquettes if I send him a Facebook message and ask for details. Good idea? Bad idea?

So i made my first few attempts into a video:

https://www.youtube.com/embed/V4-tzefdBQM

Some success and failure, but you can stare at my beautiful brown econoline if you get bored.

Also here's what i was making:

coin for scale. It's WAY easier to melt aluminum, let me tell you. Copper ain't so easy but it IS possible.

I have a foundry project. I've been working on it for 30 years. I have all the pieces. One of these days, I'll put it together. I figger that with a foundry to cast out somewhat round shaped objects and a metal lathe, I can make about anything from Aluminum.

I have a Formlabs SLA 3D printer. I have Solidworks. I have a desktop scanner.

This foundry E36 M3 is way too close to hitting the critical mass of technology confluence that disrupts my life. I must resist.

In reply to NOHOME:

Do it, come to the dark side, we get to play with fire

Getting a foundry hot enough to melt steel isn't in the cards right now, but after a bit of reading it seems that annealing is well within reach. That means forge welding may be in reach, too.

Rufledt wrote: In reply to Hal: I hadn't thought of using castings to make tools, but that opens a lot of possibilities! Watching some videos of people milling their castings makes me want to get a lathe, but one thing at a time.

After making the castings we had to do all the machining of them and other parts. We used:
Shaper to make the bottom flat
Horizontal mill with an end mill to bore the shaft hole
Horizontal mill to machine surfaces where parts met
Lathe to machine pulley
Lathe to machine shaft including cutting left hand threads on one end
Drill press to drill holes needed (Had to sharpen all the drill bits first)

Only machine I can think of that we didn't have/use was a vertical mill.

Ok with lots of advice from the very helpful people over at the alloy avenue forum, I'm going to give copper another try. They suggested the problem I was having was most likely oxidation of the molten copper, not ash flying in. I got some tips for how to prevent that moving forward.

One such tip was to use a flux that forms a coating on top of the molten copper to prevent oxygen from getting to it. One of these is simple bottle glass. Throw a chunk in at the start and it will met before the copper, then float on the surface. Another suggestion was using charcoal itself. The guy said to add some powder, small charcoal bits at the start, then a second coat on top of the pool when the copper starts to puddle in the bottom. This provides the coating, but also any oxygen that gets down there will react with the hot charcoal and burn as opposed to getting in the copper puddle.

Both awesome tips that are easy to test. Those guys respond fast, and with a long post of nerd-level theory as to why it works. It's awesome. It's like when I asked here about sheet metal welding. 4cylnderfury is right, it's like the GRM forum of metal casting.

First up, copper muffins, then onto a small xmas gift project. My dad has a bunch of copper scrap that my mom hates to have lying around. She also has a fancy new hammered copper sink. I want to make her a cast copper picture frame or something to decorate her kitchen using some of that copper scrap. I figure it's a triple xmas gift- it matches her new kitchen, it's hand made which is he kind of thing she loves, and it cleans up her garage.

Also has the side bonus of me getting to play with fire, and I'm keeping all the extra copper. There is some fancy copper flux called phosphorous copper or something like that I might get before doing the actual casting, but I'll just do the ingots without it.

I REALLY must resist the urge to cast a bunch of parts for the powerwheels project out of copper. It wouldn't look right and it would weigh wayyy too much... Must resist...

Rufledt wrote: I REALLY must resist the urge to cast a bunch of parts for the powerwheels project out of copper. It wouldn't look right and it would weigh wayyy too much... Must resist...

ok i think i figured it out with some help from various internet sources. I was using too much air, not enough fuel. This is in part because my crucible is too big (can't fit enough fuel between it and the bucket). Now it looks like this in action:

Now it's filled to bursting. As someone said, the briquettes leave way too much ash in the bottom. I'll stick to hard lump despite what i said before about switching. By "stick to hard lump charcoal" i mean "until i switch to propane or get some anthracite." It still needs time to melt copper and I suspect it is BARELY over melting temperature. It doesn't stay fluid like aluminum does as i pour. I'm probably not heating it quite enough to pour, and also i'm probably overheating the crap about aluminum. Not much control of temperatures with a bucket of charcoal and a hairdryer!

I ended up with a couple of these:

One of these pucks weighs as much as an aluminum muffin!

I think what I really need is a better, non-crap based foundry and maybe a propane burner. That or a ton of aluminum to melt because copper is pretty high temp stuff and it's taking its toll on my plaster/sand insulation. There is a reason this is the quick and easy diy foundry, it doesn't last a whole lot longer than it takes to make!

Coating of general purpose furnace cement may put off the cracking in your insulation for a cheap fix. Haven't done the home brew Portland cement/ silica sand / Perlite/ fire clay refractory, may be a step up but sounds a compromise as it has it's limits, web says the portland will melt out at higher temps like associated w/ propane.

We poured a castable insulation (mortar) for a NG steam generator while replacing the steam coil. While it didn't see direct flame, only flue gas, the old refractory saw 7-8 months of operation/ year for 8 years, saw some cracking but never a shut down or safety situation. Took an air chisel and lotta berkeleying work to bust it up, pretty berkeleying stout stuff there. A lot thicker than a backyard furnace tho.

On our NG steam boilers, we use a moldable ceramic fiber mix (Tiger-Hair like) and finished w/ coating cement to patch between bricks and casted refractory. Great stuff too but probably costly for the budget backyard DIYer.

Found on the webs KS4 refractory cement (mortar) good to 2600° or Kast-O-Lite 30 rated 3000°. From what I seen so far I'd spend the coin on either and top w/ coating cement but I tend to overbuild.

I'm really digging the sport coat while melting metal look.

You already sucked me into making my own bow (I still haven't finished it) and now you got me wanting to melt metal. And buy a sport coat.

The sport coat is a very important part of melting metal! It's literally the only kind of wool coat I have, and I have a few of them. My work jacket (the usual dirty outfit) is polyester, so I'm required to dress fancy to run the foundry.

If you are planning your own fancy-dinner-out/metal-foundry-operating dual-purpose outfit be sure you get only wool tweed sport jackets. For fashion and safety.

Also they are like $4 at good will. Nobody wants grandpas smelly old tweed jacket.

OK so I have officially found the guide to falling down this particular rabbit hole:

Basically it's a 7 book collection, starting with the construction of a better foundry. I need a better foundry because as of yesterday, mine is starting to crumble. Copper needs some pretty high temps and I guess the ghetto playsand/plaster mix in a bucket has a hard time with 2000+ degrees...

The following projects build on one another making a whole bunch of tools, using the tools already made. The tools are basically a list of things i wanted to own at some point in life.

The only downside is that the sheet metal brake is the final book, and i could really use one of those right away for the powerwheels project. Like, it's literally the next thing i need to do with that project. Looks like it's time to break out the hickory boards and wood clamps again. Lumber brake FTW.

Yeah, I have that book 1, the charcoal foundry. Bought it about 30 years ago.

The Gingery series: Commonly agreed upon, by all garage nerds, as the event horizon of a black hole. A particularly nefarious one that prefers to swallow free time and sanity.

Welcome brother

Good news! i'm getting better every time i try to melt copper:

bad news, my foundry died doing it:

plaster and play sand doesn't like 2000+ degrees. but at least it worked! i'm going to rebuild it but not using the plaster. I got some castable refractory cement that should wokr much better. It still isn't the good mizzou/kast o lite foundry cement, but it's gotta be better than plaster. I'll probably just use it for aluminum from this point on. The Gingery book has a plan for a bigger, better foundry that i'll probably build for copper alloys and for larger amounts. Until then, I think i'm going to stick with aluminum or maybe attempt some alloys.

The people over at alloyavenue have been extremely helpful and informative, and they say pure copper is quite difficult (and not particularly desirable) for casting, but a lot can be added for different alloys. I don't have tin to make bronze (though lead free solder would work in a pinch for small amounts), but aluminum can be added to make aluminum bronze. It's not easy to cast either, but it's easier than copper, and it comes out ultra tough. I guess it's used for bearings and propellers on giant navy ships and stuff. That would be cool to try. Also adding phosphorous copper shot makes the copper more fluid and removes impurities/oxides. I didn't use any of that since i was just making ingots (and i don't have any) but it's cheap enough for a long term supply. I'm just on a buying freeze at the moment since the extra money is going for xmas presents, but this will continue soon... i just need to rebuild this bucket.

I also need to scrounge up some more scrap cast aluminum. cast aluminum contains silicon which makes it nice to cast and machine. All my pop cans and heat sinks are more pure, and i don't have silicon to add to it. I have some to get me started, i'm sure i can find lots more in our storage unit of discarded appliances...

Have you not scored any alloy wheels yet as a source of raw material?

not yet. Honestly i haven't looked much what with being occupied struggling to get this copper to melt. I have a set of alloy wheels that i am almost guaranteed never to use that i could cut up. I got them basically included with a used set of snow tires that are currently on my wife's car. The problem is they are in perfect shape and i can't quite bring myself to ruining functioning things. I will melt them eventually i'm sure, it's just going to take some mental processing first.

I have three scrap wheels just hanging out behind my garage just waiting for to build a foundry.

Rufledt, you should post the wheels for sale. Functional wheels probably net money enough to buy double the scrap aluminum than the functional wheels are worth.

Eddie2799 on Youtube had talked about building a 55 gal. drum furnace to melt down whole aluminum wheels in one shot. That I wanna see.

Note that in the Gingery book, he suggests clay and sand. Even garden sourced clay.

So I'm on Amazon building up my xmas shopping, and took a look at refractory cement. This isn't what I thought it would be. Everything comes like drywall mud in buckets, and seems to cap at 2200F except for the "indoor use only" stuff.

Isn't there some sort of dry mix stuff to use as an upgrade to the playsand/plaster? Or would these cements work for that sort of backyard foundry? Not really looking to melt much more than cans and copper or brass in those sorts of sizes so the bucket looks perfect for my uses.

I'm also looking at the clay graphite crucibles. They're much much cheaper than expected, but sizes are a bit of a mystery to me.