Home made foundry question

[Barnbikes]

I want to build a small foundry with my 2 oldest sons. My intent is to melt aluminum and occasional brass (bullet cases).

I was thinking of using a clay chimney liner as my inner chamber,Steel pail as my outer form and sand/plaster paris as my filler between the 2. It would have a 2-3 layer of sand/plaster paris layer in bottom of flue piece.

I have searched on line for top temperature limits of clay flues and it looks like it is in the 1800f - 2000f range. It has the same range as refractory cement.

As a young teenager I used to help a elderly neighbor cast hit and miss engine mufflers. So it is not exactly a new thing to me. His set up was a 35 gallon steel barrel with 2 layers of recycled chimney bricks.

Is this a ok set up?

Thanks,
Jon

 

[Dave Sohlstrom]

One good source of info is the book by Michael Porter " Gas Burners for Forges, Furnaces & Kilns" isbn 1-879535203

Dave

 

[LSEW]

Jon, see if you can find the Steve Chastain books. There are 2 on building everything for your home foundry. And I mean everyting. they are inexpensive, easy reading, and have an enormous wealth of information.

Good luck on a great hobby,
maury

 

[bmac2]

I Jon
If I remeber right normal operating temp for clay chimney liner is something like 600c and up to 1000c in case of a chimney fire so that should be fine for aluminum. I’m not sure that the sand/plaster filler would be of much benefit and I would be concerned about the plaster absorbing moisture. Most furnaces have a metal outer shell, an insulating layer and then a durable hot face on the inside. Personally I think you’d be better off using perlite available from garden centers https://en.wikipedia.org/wiki/Perlite. It’s cheap, light weight, a good insulator and can take the heat. My first furnace was a mix of perlite and fire cement for the hardware store.

Some free books (I like free)
Though the scale of some of the things they discuss is a little on the large side for the home user. A good reference is the “US Navy Ship Foundry Manual”
http://www.hnsa.org/resources/manuals-documents/single-topic/foundry-manual/
I would also highly recommend the “The Hobbyist's Guide to Casting Metal--2nd Edition”. http://www.alloyavenue.com/vb/showthread.php?2469-Foundry-Tutorial-Book
It has a lot of good practical information at a hobbyist level. Like how to test if that great scrap aluminum you found is actually magnesium. I’ve seen videos where someone drops a piece of magnesium into an aluminum melt . . . bad . . . very bad.

 

[kosmos]

Hi Jon,

I have some photos of my casting equipment on my homepage.

http://www.kunst-mit-mechanik.de/Meine-Werkstatt/Giesserei

Best regards,

Joe

 

[henniesfoundry]

I designed and built an oil burner as well as furnace. My burner can reach temp of approximately 2500 degree celsius.
Designed my own sand mixture (greensand)
Doing aluminium and brass casting. You are welcome to e mail me with any questions.
E mail : [email protected]

 

[abby]

Jon , it is quite feasible to melt aluminium in an open wood fire using a crucible made from a piece of steel pipe , no fancy burner , furnace or chimney required just a source of dry wood.
There is no noise and sitting around the fire waiting is a very pleasant experience.
Most other metals with the exception of iron can be melted using coke ( hard to source now in the UK) and draught provided by 10 feet of chimney.
The equipment required is down to how much you intend to do.
Why waste time making a sophisticated foundry if you only want a couple of castings .
If you do get the bug I would recommend the use of a castable refractory concrete for your furnace and propane as fuel .
The concrete is not expensive , is easy to use and is reliable so why re-invent the wheel to save a couple of dollars .
waste oil and agricultural diesel can be more trouble than it's worth with smoke , smell and noise.
Casting is a very satisfying process , producing a useful or artful piece from a handful of scrap gives you a sense of elation but much can go wrong between the start and end , keep it simple and learn as you go.
Dan.

 

[Buchanan]

I tried to melt shell casings for casting many years ago. 1985! The brass alloy is designed for hot pressing, I believe. The brass melts in a cruicable bit stays a plastic mass rather than becoming a fluid. Old taps and other scrap brass melted fine but I never had any success with shell casings. Perhaps somebody else has had better experience with them.

 

[nel2lar]

[QUOTE="Barnbikes, post: 285972,

Is this a ok set up?

Thanks,
Jon[/QUOTE]

Jon
It is not a matter if it is ok or not. It matters if it works and that will give you the answer you search out. I have seen many different approaches at melting and burner making. If it works for you who am I to say it is wrong. There are many out there that will take a different direction, but if it works, who cares.
You will be in business. The only thing do not get disgusted at bad results. This is something new and you will learn as you go.
Nelson

 

[arvidj]

Jon, see if you can find the Steve Chastain books. There are 2 on building everything for your home foundry. And I mean everyting. they are inexpensive, easy reading, and have an enormous wealth of information.

Good luck on a great hobby,
maury

Yes, the original post was several years ago. Sorry about that.

Maury mentions two books but looking at the current offerings from Steve Chastain on Amazon ... search ... it is not obvious to me which ones he was talking about. Anyone have any suggestions as to which two Maury was talking about?

Thanks,
Arvid

 

[abby]

Brass shell casings are made of the appropriately named cartridge brass which is 70/30 Cu/Zn , it does require a slightly higher temperature for melting but should be easily attained in well designed home furnace.
It is likely that the formation of zinc oxide on the thin metal caused the pastiness , a little borax flux should overcome this and prevent excessive metal loss.
Dan.

 

[LorenOtto]

I have been saving brass cartridge shells for many years with the thought that I may use them in the future like Jon. Someone told me along the way that cartridge brass was not good for casting. I am glad to hear that with a little borax flux it can work. I will keep this little nugget of information for the future. Thanks Dan.
Loren

 

[nel2lar]

Shell casings, that would take a hole lot of casing to make anything large.

Today I was at a tire store getting a couple of and bored out of my head. I hate sitting not able to do anything. So I went walking around with my buddy a Poodle named Munchkin and looked down and seen a valve stem. Make a long story short, pulled out my pocket knife and cut away all the rubber to expose all that pretty brass, yellow brass. I have been melting anything that is brass with a little bit of copper and at the last moment press a piece of lead into the melt. Once melted stirred and pulled and made ready to pour. I have found the copper and lead makes the brass go further and machines so nice.

Maybe we all could ask our local tire store and hit the owner up to a nice cylinder of some sort and have the employees to toss all the old valves in it and go around and collect your precious yellow metal.

Hope I haven't spoiled it for anyone.

Nelson

 

[abby]

As there appears to be some interest in collecting scrap for melting I thought some of my experience might be helpful.
Not all yellow metal is brass , gearbox synchro cones and selector forks are aluminium bronze as are some boat propellers , not very useful for model castings.
Aluminium bronze is harder than brass and shows a slight magnetic attraction.
Melting and casting chrome plated scrap can sometimes leave bits of chromium in the casting , this can result in surface defects if the castings are machine polished.
The original use should give clues to the composition but aluminium scrap can be dangerous.
If the aluminium in your crucible catches fire , most likely a piece of magnesium is present , don't panic , turn off the heat and pour some DRY sand to cover the flames.
Carefully remove the crucible to a safe area. I have had this happen and it is very scary the first time.
There can be many toxic constituents present in scrap metal including Arsenic in Aluminium and Cadmium in copper (silver soldered joints etc) also Lead in varying amounts.
Zinc although not especially toxic can rapidly fill the workshop with dense white smoke that condenses and falls like snow , breathing these fumes can cause "Zinc shakes" as does welding galvanised steel.
Drinking milk is supposed to help prevent this but I recommend that as well as eye protection you wear a fume protecting respirator or at least have a well ventilated foundry.
Old horse furniture can be a good source of nickel brass (german silver) old mouth bits , bridle fittings and stirrups can often be bought cheap at farm sales , always look for old EPNS cutlery at car-boot and garage sales.
Carry a small magnet when you are out and about and check scrap price trends at least weekly if you are buying as prices can fluctulate dramatically in a day.
Dan.

 

[mohavegun]

Locksmiths will often save and sell junk keys, all brass keys are good for melting, the chrome and nickel plated keys also will melt OK but you need to flux when mixing brass scrap... ALWAYS! as for using plaster of paris, bad idea, it does not hold up well with repeated heating and cooling, use refractory cement, much better and even cheaper. Ask around at your local lumber yards, someone will probably order a bag of it for you. If someone in your area does boiler or furnace repair, they would have it. A long time ago I bought a gallon of ceramic slip from a ceramics shop and mixed it with sand and made a foundry furnace shell liner, it worked fine for several years but it did crack, I ignored the crack and kept using it. As for alloying materials, clean copper scrap is a good additive to aluminum, about 1/2% of copper to aluminum per pound will increase the ductility of the aluminum and make it stronger as well. I melt a lot of extruded aluminum, window and door frames, tubing and structural, which is generally pretty soft, adding a small amount of copper to this type of aluminum is a good idea. Car pistons have lots of silicon in them and make very rigid but brittle castings but it works very well for aluminum castings like model engine castings, flywheels, etc.. The steel in car pistons sinks to the bottom of the flask and you can dump it out at the end of the pour. Contact your local Harley Davidson dealer, ask him about junk lower end castings, on most of the newer Harleys the main bearings are cast in and when they go bad the lower housings are junk. It is a very good grade of casting aluminum and casts and machines very well. As for magnesium, don't fret but be careful Not to mix with aluminum, I have successfully melted magnesium and made castings from it, no flux is required and even though some of it burns, the fire goes out when you pour it in the sand or it cools below kindling temp. You should use separate crucibles for each metal. Look around locally, if there is a screw machine shop in your area you can probably buy good clean brass scrap from them because most screw machine operators generally have a lot of brass products and so a lot of brass scrap which they keep clean for resale. Generally type 260 brass is best for melting and casting. I have been casting metal parts for my hobby for nearly 40 years. My current aluminum foundry will melt up to 60 pounds at a time.

 

[nel2lar]

If I wanted to I could write a book on the best reasons NOT to build your own foundry. Too much negative, but you all forgot to put in there how dangerous molten metal is.
I do not understand.
Nelson

 

[abby]

Nelson I do not understand the thinking behind your last post , molten metal can be dangerous if not handled with care , so can solid metal if you drop it on your foot.
Using metal cutting machines can be dangerous , so can crossing the road.
If I wanted I could write a book with the best reasons why you SHOULD build your own foundry.
Foundry work is one of the oldest of mans skills and one of the most rewarding .
I guess you could take up knitting but then again you might poke yourself in the eye.
Dan

 

[nel2lar]

Dan
Did not mean to ruffle your feathers. It seems like it is all so bad, I do not understand. Yes it is dangerous and if you watch this short video you will agree.
http://www.homemadetools.net/forum/...medium=email&utm_campaign=10-15-18#post119330

 

[SmithDoor]

Pouring is very safe if you use all the safe equipment and follow the rules.
I have poured 140 lbs of braze at time and melted 250 lbs at one time for 20 years.
No one was hurt or burned

Dave

If I wanted to I could write a book on the best reasons NOT to build your own foundry. Too much negative, but you all forgot to put in there how dangerous molten metal is.
I do not understand.
Nelson

 

[nel2lar]

Dave
That is the way it should be every time even when mishaps happen like in the video. I believe they were pouring a lot of metal and it looked like no one was injured. If you are in tune with everything we all get to go home.
Nelson