# Devil Forge users or DIYers.



## COMachinist (Jul 29, 2021)

I have been thinking, with the price of metal and things going up so much, I’m considering doing some metal recycling.
Casting some of the softer metals copper, brass/bronze aluminum. I have access to lots of scrap, from my sons auto shop. Being family I get 1st pick of, wheels, AL heads, etc brass parts, Don’t figure oil bronze is worth messing around with. I searched this forum on casting not much available here, mostly welding posts. Any way looking at the Devil Forge line, figuring the 8-10 kg size. I have 3 100# propane bottles, and get them filled from my Co-op up the road, so fuel is readily available, at a good price for now. Any one casting parts?
CH


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## benmychree (Jul 29, 2021)

It is not as easy as one might think to produce clean sound castings, especially in bronze, aluminum can be a bit difficult if permanent mold scrap is used due to shrinkage problems, brass is easy.  I used to do a lot of it years ago.


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## rwm (Jul 29, 2021)

I have done much casting. Home cast aluminum machines like crap. There are multiple reasons for this. Bronze/brass are much better if done right. 
Robert


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## ericc (Jul 29, 2021)

I do it.  It is a lot of fun, but it requires a single minded concentration and a focus on safety.  My focus was not so much on saving money as it was to get rid of some of the junk branches sitting around my house.  They tend to accumulate, and can become dangerous if they are inside the defensible space zone.  My main goals were to get rid of some of this yard waste cleanly without subjecting the neighbors to unsightly burn piles or permanent furnaces.  There is not much on the Internet about this angle, so I ended up discovering a lot of things on my own.  Shrinkage is not a problem if you are willing to cast oversize and turn a lot of your metal into chips.  Casting to size and obtaining a good surface finish is more difficult, but entirely possible.

As for casting aluminum and brass into ingots with a Devil Forge, there is plenty of stuff on the Internet about that, especially on YouTube.  I just cannot justify the propane expense.  All my propane goes into my blacksmith forge, which has a larger bang (  ) for the buck.  Propane is less expensive in the 100 lb tanks, so you will be ahead there.  There are a lot of experienced people here who can give you advice.  Pay special attention to safety and the use of good safety equipment.  I wear welding gloves, safety glasses and a face shield, leather apron, and a hard hat.  You don't need the mesh screen for the lower temperature metals, and I have spats, but don't use them for aluminum, although I do have a friend who burned his foot severely by spilling aluminum on it.


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## benmychree (Jul 29, 2021)

Brass is easy because the zinc in it excludes oxygen from the melt, so porosity is not a problem; bronze, on the other hand does not contain zinc, at least most of it does not, so the melt must be protected from oxidation and uptake of furnace gasses; a flux is used and a degassing inoculation is needed, otherwise porosity is seen.  Porosity is also common with aluminum castings.  Problems with shrinkage when using permanent mold scrap such as pistons and wheels is due to the addition of iron to the alloy to prevent sticking of aluminum to the molds; iron narrows the solidification range of the molten metal, making it necessary to raise the pouring temperature in order to get complete filling of the mold and also getting consequent shrink problems such as cracks or hot tears.


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## COMachinist (Jul 29, 2021)

Robert, I’m just trying to save some on metal parts that can be cast, then machined. I have seen video’s of guys 3d printing models, or making out wood, then casting and machining to finish. I cant see using a new hunk of aluminum for a pulley or a pot metal replacement part when quality or strength isn’t that important.
besides it’s fun to do something yourself.
Thanks for the reply.
CH


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## benmychree (Jul 29, 2021)

ericc said:


> I do it.  It is a lot of fun, but it requires a single minded concentration and a focus on safety.  My focus was not so much on saving money as it was to get rid of some of the junk branches sitting around my house.  They tend to accumulate, and can become dangerous if they are inside the defensible space zone.  My main goals were to get rid of some of this yard waste cleanly without subjecting the neighbors to unsightly burn piles or permanent furnaces.  There is not much on the Internet about this angle, so I ended up discovering a lot of things on my own.  Shrinkage is not a problem if you are willing to cast oversize and turn a lot of your metal into chips.  Casting to size and obtaining a good surface finish is more difficult, but entirely possible.
> 
> As for casting aluminum and brass into ingots with a Devil Forge, there is plenty of stuff on the Internet about that, especially on YouTube.  I just cannot justify the propane expense.  All my propane goes into my blacksmith forge, which has a larger bang (  ) for the buck.  Propane is less expensive in the 100 lb tanks, so you will be ahead there.  There are a lot of experienced people here who can give you advice.  Pay special attention to safety and the use of good safety equipment.  I wear welding gloves, safety glasses and a face shield, leather apron, and a hard hat.  You don't need the mesh screen for the lower temperature metals, and I have spats, but don't use them for aluminum, although I do have a friend who burned his foot severely by spilling aluminum on it.


I do not worry about shrinkage for dimensional accuracy, but for casting defects such as cracks and hot tears.


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## rwm (Jul 29, 2021)

COMachinist said:


> Robert, I’m just trying to save some on metal parts that can be cast, then machined. I have seen video’s of guys 3d printing models, or making out wood, then casting and machining to finish. I cant see using a new hunk of aluminum for a pulley or a pot metal replacement part when quality or strength isn’t that important.
> besides it’s fun to do something yourself.
> Thanks for the reply.
> CH


Sure. That is a reasonable application. Initially I though I might be able to cast round stock for the lathe. That does not give an acceptable result in aluminum. I have had good success with brass and silicon bronze. I just sent out some nice gear blanks in brass.
Casting parts that need some machining is fine but the finish will not be as good as extruded stock. Control of porosity is a big issue with aluminum and heat treating is hard to do in a home shop.
Robert


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## benmychree (Jul 29, 2021)

One must be really careful to avoid mixing silicon bronze and other bronze alloys; the result is as brittle as glass and will flake like obsidian.


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## RJSakowski (Jul 29, 2021)

I have two books by Terry Aspin, published in the UK; "Foundrywork for the Amateur" and "The Backyard Foundry".   I also have The Metalcaster's Bible" by C.W. Ammen.  These were purchased long ago and may be out of print but you may be able to find copies on Amazon.

I have cast white metal, aluminum, and some brass.  For the most part, I cast raw material for use in machining.  Aluminum tends to be porous but for some projects where I need a lot of mass and I am not particular about ultimate strength or surface finish, it beats spending a bunch of cash.  

For raw material molds, I often use cans from soup, vegetables, coffee, etc.  For a heat source I will use my coal fired forge.  We have wood furnace for winter heat and it is a convenient way to melt aluminum and brass.


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## ericc (Jul 29, 2021)

benmychree said:


> I do not worry about shrinkage for dimensional accuracy, but for casting defects such as cracks and hot tears.


I think that hot tears is mainly a problem for castings that have changes in dimension and stress risers.  It is not so much a problem for casting rough blanks that will be machined.  I don't have that much experience.  The main reason I did this was to make some stock for some gear blanks, which incidentally worked just great.


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## kvt (Jul 29, 2021)

I am also looking to do some of that,  I have a bunch of scrap Brass, Copper and AL.   What do you use for flux on The various metals.   
or degas agents.   I have done some brass, and Make my own lead fishing weights.   But one try at AL did not go good, due to the bubbles in it.


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## rwm (Jul 29, 2021)

Gas porosity in aluminum is predominantly from hydrogen dissolved in the melt. Unfortunately with gas fired furnaces, hydrogen in the combustion gases can go directly into the melt. Degassing is complex and it is best to avoid absorbing gas at all. Good melt practices including use of clean metal, rapid melting, keeping the melt at temperature for the minimum time to pour etc. will help reduce gas porosity. Use of an oxidizing atmosphere after achieving melt temperature can help. I am convinced that electric furnaces absorb less H2 but they have their own issues (I have both.) Using casting alloy like A356 will give superior results to scrap extrusion alloy.
Fluxing does not help with degassing. Flux for aluminum is often Lite Salt (Na K Cl mix).
Brass is a whole other animal and I would recommend Ammen's book 'Casting Brass.' 
Benmychree is totally correct about mixing leaded and Si bronzes. You should even have separate crucible for these. If you want to cast a really easy bronze try silicon bronze (Everdur.) It makes no dross and pours like water. 

Robert


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## rwm (Jul 29, 2021)

3D printing is a great way to make patterns as you suggest.
Here is an example of a welding clamp:



Cast in brass:






Robert


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## savarin (Jul 29, 2021)

My first furnace was charcoal and a hair dryer with a tin can for a crucible.
The tin can is suitable for one melt of aluminium but no more.
Mr current furnace was Made  from a garbage can and fire proof cement, fired with propane.
Made heaps of castings in aluminium and brass.
The best aluminium cast was a failed melt in a stainless bowel.
It started to leak before I thought it was all melted but it set perfect with no tears or porosity so now I pour as soon as possible  and this along with an oxidising flame once it starts melting seems to have minimised porosity really well.
Tears and shrinks can be minimised by ensuring the cast is planned to reduce very thick sections to the minimum.
Machining the cast aluminium is almost like turning wood, the swarf soaks up every scrap of oil everywhere it lands just like sawdust.
I keep meaning to look into heat treating the castings so see if it is possible to improve their machinability


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## rwm (Jul 29, 2021)

Don't forget about lost foam casting for aluminum. You can get some amazing results.
One of our members is also a member at The Home Foundry and has done some remarkable work. Check it out here:









						Automotive Intake Manifold – Boss 302 Independent Runner
					

Ok, instead of an intake manifold lids, let’s make the whole darn intake! It’s an independent runner Boss 302 intake for a pair of Inline Autolite...




					forums.thehomefoundry.org
				




Robert


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## COMachinist (Aug 2, 2021)

Well I’m thinking about which size I should get. I’m not planning on doing a lot of casting just the occasional part to machine for a repair or project. I generally don’t do a lot of scraping like the guy from Australia, Big Stack is his screen name I think. I do have a bunch of copper wire and quite a bit of copper pipe after a home re model project over the winter, not much brass but a few lbs of 360 lathe chips.
Thanks for the input, that Boss Manifold was impressive from a home foundry. He has the quite the furnace set up. I remember the Boss 302 and Z28 trans-am wars when I was a younglin in the late 60’s. Great video.
CH


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## Bi11Hudson (Aug 2, 2021)

There are a lot of responses about *safety*, both here and on web sites. What is not covered, to my satisfaction, is the *details* about safety. Glasses, a "fire retardant" jacket and trousers, hard shoes, gloves are all touched on. But none in detail. . . I have worked in foundries and steel mills all my adult life. The one thing I recall from early childhood was the plumber's lead pot for caulking cast iron pipe. A drop of sweat on the hot lead will cause an explosion. The first time I played hookey was to hang out at a construction site at age 6 or 7. Kitchen grease has a similar charactistic.

As an adult(?), well ex-military anyway, I was working as an electrician at an iron foundry. A device called a "stir beam" was used on ten ton ladles. The hoist required repair, with the beam hung above the ladle. The stir beam was "green", in that it had not had the moisture cooked out of it. When the hoist was repaired, the operator lowered the beam into the ladle before we could get clear. The resulting explosion injured a half dozen people, fortunately none fatally. Most of my scars came about when I stopped to pick up the Chief Electrician, who had been knocked over. Just because I'm getting older doesn't mean I have to grow up, does it? At the dispensory, someone mentioned having smelled hair burning, at which I immedietlly looked for a mirror to check my mustasche.

On a smaller scale is the "home foundry", and much more likely to experience such an "accident". It isn't an accident, it is a matter of carelessness. Aluminium melts at about twice the temperature of lead. Copper, Zinc, and by derivation brass and bronze melt at much higher temperature. A drop of sweat is mostly water. Water flashes to steam at 100C, 212F. Steam is water at sixteen(16) times volume. Anything around it has to go somewhere. Molten metal is about the consistancy of milk. A drop of sweat can cause hot lead to fly upwards of 7 feet. Call it two meters. . .  Aluminium and other metals are even more disruptive.

And that's just a drop of sweat. There are many other safety issues dealing with hot metal. It should *never* be taken lightly.

EDIT: Link to another post having a similar point.








						Let's Be Careful Out There!
					

Neighbor/Acquaintance/Sorta Friend has a garage just up the road from me.  Wheeler-Dealer Horse Trader and Shade Tree Mechanic.  Always has a couple of projects going on, old cars and trucks (30's to 60's) etc.  He was grinding on something a couple-three weeks ago and the sparks got into a pile...




					www.hobby-machinist.com
				



.


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## COMachinist (Aug 3, 2021)

Bi11Hudson said:


> There are a lot of responses about *safety*, both here and on web sites. What is not covered, to my satisfaction, is the *details* about safety. Glasses, a "fire retardant" jacket and trousers, hard shoes, gloves are all touched on. But none in detail. . . I have worked in foundries and steel mills all my adult life. The one thing I recall from early childhood was the plumber's lead pot for caulking cast iron pipe. A drop of sweat on the hot lead will cause an explosion. The first time I played hookey was to hang out at a construction site at age 6 or 7. Kitchen grease has a similar charactistic.
> 
> As an adult(?), well ex-military anyway, I was working as an electrician at an iron foundry. A device called a "stir beam" was used on ten ton ladles. The hoist required repair, with the beam hung above the ladle. The stir beam was "green", in that it had not had the moisture cooked out of it. When the hoist was repaired, the operator lowered the beam into the ladle before we could get clear. The resulting explosion injured a half dozen people, fortunately none fatally. Most of my scars came about when I stopped to pick up the Chief Electrician, who had been knocked over. Just because I'm getting older doesn't mean I have to grow up, does it? At the dispensory, someone mentioned having smelled hair burning, at which I immedietlly looked for a mirror to check my mustasche.
> 
> ...


Yep know all about liquid metal. I worked two summers, in a zinc smelter in the stove building drawing the metal then pulling down the front of the stove and replacing the broken pots in the stove then charging and replacing the coney’s (the cones on the front of the pots)  Next day we would cast the 600 and 1200 lb ingots then do it all over again. 4 times a week. We only worked 4-5hr and got paid for full 8hrs. It sure as hell got me in shape for Fall football training late summer.
CH


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