Casting your own steam engine castings?

[HenryBanjo]

Hello,
I was wondering if anyone has tried to cast their own model steam engine castings? if so how did it go? any tips if I want to try it?
Thanks

 

[Jasonb]

Have a read through this section of the forum

https://www.homemodelenginemachinist.com/forums/home-foundry-casting-projects.36/

 

[HenryBanjo]

just had a read thought and I think that answers my questions, Thanks!

 

[GreenTwin]

This one, made from 3 photos found online.
Making your own castings in iron is a blast to say the least.

This is my first engine, and my first attempt at making castings.

I would not say it is necessarily easy.
There is a learning curve, and some expense for equipment and molding sand.

 

[GreenTwin]

Some photos.

 

[GreenTwin]

Some crazy 3rd degree burns from tiny beads of iron that splashed back on my jacket and ran down into my gloves.
No pain though since the nerve endings are vaporized.
Use Curad "silver solution" if you get burns like this.

 

[GreenTwin]

There is nothing quite like pouring molten iron.
There are a few here who pour their own iron engine parts.

 

[GreenTwin]

My recommendations:

1. Start with a simple propane burner, simple crucible (perhaps made from steel), and a simple furnace from stacked hard fire brick.
2. Finding good casting sand can be tricky. Be sure you don't pour molten meltal into anything that has ANY moisture in or on it (see my burns above). Ingot molds have to be heated to perhaps 500 degrees to drive off the moisture.
3. Try a few simple castings in aluminum, without spending much money, and then if you really like it, you can ramp up to a more serious furnace and other equipment.
4. Wear lots of safety equipment such as leather jacket, gloves, and leather boots. Full face mask attached to a hard hat.
5. Most of the things you need for a durable (long term) furnace and good molding sand cannot be found in a hardware store, in spite of what is often stated online. You can make things that last a short period of time from hardware supplies, but if you want things to last, find a foundry supply house.
.

 

[GreenTwin]

A simple furnace can be made by stacking hard fire bricks in a circle, with a few at the bottom.
Hack a hole in the bottom of one for a tuyrere (burner entry into the furnace).
Wire around them; they don't really need to be cemented initially for aluminum work.

I used a kiln shelf for a lid.
Very simple way to melt aluminum.

A simple propane burner design is a Reil.
A self-aspirating propane burner will melt aluminum, but needs a damper on it to adjust the combustion air.
Some propane burner designs do not show a damper, and they do not work well with a foundry furnace.

 

[GreenTwin]

100model (aka luckygen1001, aka ironman) is a member here, and was one of my mentors with learning how to cast gray iron.
He taught me a lot.
.

 

[GreenTwin]

This is one of my more recent iron pours, which was a belt buckle/plaque sort of a thing, so as to have something to cast during COVID, when all the iron pour events were closed down (and still are).

I showed this video to someone, and they said "Where is the fire extingisher? There is none to be seen !!!".
My first thought was "Why would I need a fire extinguisher?", LOL, but of course that would be a good idea, assuming it is the right type of extinguisher.
You certainly don't want any type of water or even moisture near molten metal, else you can cause an explosion.

I use a Delavan siphon nozzle burner with 30 psi compressed air, and a Toro variable speed leaf blower for combustion air.
The start sequence is to put a lit paper towel into the furnace, turn on the diesel and compressed air at the same time (the burner can be operated this way without a combustion air blower if you are just melting aluminum), turn on the leaf blower (on the LOW setting) with the dump valve open, and slowly close the dump valve to put full combustion air into the furnace. If you suddenly apply full combustion air, you can sometimes blow out the burner, in which case you close the compressed air and fuel ball valves and start over again.

The first air regulator delivers 30 psi to the Delavan siphon-nozzle burner, which operates at about 2.7 gal/hr diesel.
I put 10 psi on the fuel tank via the second air regulator, to give a consistent burn, and so I never have to adjust the burner.
The tank has a 30 psi safety valve on it.

The furnace and lid have a 1" think Mizzou 3,000 F castable refractory, then a layer of 2,600 F insulating fire bricks, then two layers of 1" thick ceramic blanket. The exterior of the furnace remains cool to the touch during a melt. The Mizzou is very durable at iron temperatures (perhaps in the 2,500-2,600 F range), and holds up well to iron splatters. The interior is patched with a slight amount of plastic refractor as needed from time to time, rated 3,800 F. The plastic refractory is like putty, and you just smear a bit onto the interior surface if a crack opens up.

For iron work, you need shaded lenses or facemask, such as is used with an oxy/acetelene torch, since the infrared energy coming off of the furnace interior and crucible will very quickly give you a bad case of eye sunburn, which is very uncomfortable (don't ask me how I know this).

I normally don't do open-faced pours, but in this case, it did not really matter, and so I did an open-faced pour.
I poured water on the back of the casting to cool it faster, and that caused all the scabbing on the back.
The ceramic mold coat works wonders, and the castings really come out of the mold that clean and shiny.

For an engine part, you would want to leave the casting in the sand overnight, and cool it as slowly as possible, to prevent hard spots in the casting.

https://vimeo.com/manage/videos/479620524
.

 

[HenryBanjo]

Thanks for all that info. What size crucible would you recommend? I think ill use my devil forge gas forge but if that's too small then I'll make something bigger. also what do you know about using coal? it seems a bit easier than gas

 

[dazz]

Hi
I have absolutely no experience casting anything but I plan to learn to cast iron. I have looked hard at what others have done, to avoid repeating their mistakes.
Based on what they have learned, I suggest the following:

Buy the book Complete Casting Handbook by John Campbell. It is a long read but it contains a lot of practical info not found on Youtube tutorials.

I have looked at range of options for a burner. I have settled on a diesel fueled pressure spray system. It will have an electric fuel pump and blower, but no compressed air. This avoids the cost, noise and complexity of including a compressor in the system. The pressure spray system is commonly used by many commercial burners for many applications. As such, parts are readily available. I have the parts, I just haven't built and tested it yet. I have not seen a pressure spray burner used by any DIY foundry, which is not to say they don't exist.

Some use discarded cooking oil with success. I will use diesel because it is clean and with consistent properties. I am working on the basis that successful casting depends on applying a consistent process.

Don't even try to use propane or gas to melt iron (ok for aluminium). It can be done, but it is not a good thing too do. The fuel consumption rate is very high. The flame temp is too low. I have not looked at using coal.

I plan to use a thin walled refractory, backed with insulation to create a relatively low mass furnace (similar to Green Twins). This will reduce the time and fuel required to melt iron. Also, refractory is hideously expensive here.

I plan to use casting sand and sodium silicate as a binder.
I plan to use a DIY recipe ceramic coating (I can't buy it ready made in my country)

I have a 3D printer to make the patterns.

If you look at Green Twins pour video, the work area is clear of clutter and everything is carefully laid out in advance. There are no unnecessary movements made or required. Nothing exciting happens. All of this is really important for safety. Watch a few Youtube videos to see how not to do it.

Just my $0.02 worth.

 

[GreenTwin]

Buy the book Complete Casting Handbook by John Campbell.

The book is rather pricey, but the 10 rules for good castings can be found online, so I would recommend waiting on purchasing the book until you really are deep into castings things, and even then you may not need the book, but instead just use the 10 rules.

I am looking for the link to the 10 rules, and will post when I find that again.

Someone mentioned that gray iron can be melted with propane the other day, and while this is true, you either have to have a large tank, or somehow try to keep a small tank warm (without overheating it), since the vapor pressure will drop very quickly as the tank cools with the high pressure/flow required for iron melts.
Much easier to just use diesel, and then you don't have to worry about keeping the tank warm.
.

 

[GreenTwin]

Thanks for all that info. What size crucible would you recommend? I think ill use my devil forge gas forge but if that's too small then I'll make something bigger. also what do you know about using coal? it seems a bit easier than gas

Crucible size is relative.
I often use a #10, and some consider that size huge.
I have used a #30, and I have a friend who pours I think a #70.

The crucible size is roughly equal to the weight of molten aluminum it will hold, so a #10 will hold perhaps 10 lbs of aluminum (perhaps brim full), or about 3 times that for iron, or 30 lbs of iron.
Generally a brim full crucible is difficult to pour, and so you typically use a crucible that is perhaps 70-80% full.

I use Morgan Salamander Super clay graphite crucibles exclusively, and they can be purchased on ebay.
The Salamander Super can be used for any metal, but unlike most crucibles, it is ferrous-metal-rated, and also rated for iron temperatures.
I use a dedicated crucible for each metal type.

If the parts you intend to cast are small, then you could use a #5 or even smaller crucible.
It all depends on what size parts you intend to cast, with the understanding that you will need extra metal for the sprue, runners, gates, and any risers.

You can melt aluminum in a forge (a forge is sort of like a furnace laid on its side, with one end open).
No need to build a dedicated furnace if you just want to play around and melt a bit of aluminum.

The forges I have seen typically use a propane burner, but sometimes they are fitted with an oil burner.
For melting aluminum, a propane burner is sufficient.

Years ago, the trend was to put a crucible in a pit of charcoal, and burn the charcoal to melt the aluminum.
This method works, but is a bit tedious and time consuming compared to just using a propane burner.

I suppose you could burner coal around a crucible too, but I am not sure what that would do to the exterior of a crucible.
I have not seen anyone melt iron using charcoal or coal.

What I often see in the art-iron world is coke used to melt iron in a cupola.
Coke is coal heated in the absence of oxygen.
I originally though that burning coke in a cupola was a good way to melt iron, but then I tried to buy some coke, and could not find any for sale anywhere, unless I bought an entire truckload of coke.

A cupola is a large, messy, labor intensive affair.
An oil fired furnace will do the same thing that a cupola will do, but the oil furnace can be operated by one person easily.
A cupola can produce a considerable amount of molten iron once it gets started, simply by continuing to feed coke and scrap iron in the top.

Running a cupola to melt iron is a bit of an art.
I have seen it done, but have not tried it myself because I can't find a source for coke.
I have seen some fail at getting the cupola going, and had the iron solidify inside the cupola, which creates a big problem.

Even if I could find small amounts of coke now, I would not build a cupola, because they are just too difficult and messy to operate compared to an oil burner furnace.

If the only source of fuel I had was coal, then I may try it melting aluminum.
If you had a source for coke, you could melt iron.

I burn about 2.7 gallons per hour of diesel, and I don't do that many iron melts, and so using diesel is clean (compared to burning waste oil) and not too expensive for me.

If diesel prices go too high, I will consider burning waste oil, but would wear a powered respirator to avoid the fumes.

.

 

[Richard Carlstedt]

Those are all terrific suggestions that Green Twin mentioned
i made and used a cupola several times years ago, but the coke was free (friend had it)
With modern supplies ( as mentioned above) , the crucible is the way to go. I do want to mention
iron sourcing. You want good cast iron. We had a good source----used flywheels from a farm implement/engine rebuilder . The iron was clean (no sand ) and good quality . Makes life easy that way
Rich

 

[HenryBanjo]

Crucible size is relative.
I often use a #10, and some consider that size huge.
I have used a #30, and I have a friend who pours I think a #70.

The crucible size is roughly equal to the weight of molten aluminum it will hold, so a #10 will hold perhaps 10 lbs of aluminum (perhaps brim full), or about 3 times that for iron, or 30 lbs of iron.
Generally a brim full crucible is difficult to pour, and so you typically use a crucible that is perhaps 70-80% full.

I use Morgan Salamander Super clay graphite crucibles exclusively, and they can be purchased on ebay.
The Salamander Super can be used for any metal, but unlike most crucibles, it is ferrous-metal-rated, and also rated for iron temperatures.
I use a dedicated crucible for each metal type.

If the parts you intend to cast are small, then you could use a #5 or even smaller crucible.
It all depends on what size parts you intend to cast, with the understanding that you will need extra metal for the sprue, runners, gates, and any risers.

You can melt aluminum in a forge (a forge is sort of like a furnace laid on its side, with one end open).
No need to build a dedicated furnace if you just want to play around and melt a bit of aluminum.

The forges I have seen typically use a propane burner, but sometimes they are fitted with an oil burner.
For melting aluminum, a propane burner is sufficient.

Years ago, the trend was to put a crucible in a pit of charcoal, and burn the charcoal to melt the aluminum.
This method works, but is a bit tedious and time consuming compared to just using a propane burner.

I suppose you could burner coal around a crucible too, but I am not sure what that would do to the exterior of a crucible.
I have not seen anyone melt iron using charcoal or coal.

What I often see in the art-iron world is coke used to melt iron in a cupola.
Coke is coal heated in the absence of oxygen.
I originally though that burning coke in a cupola was a good way to melt iron, but then I tried to buy some coke, and could not find any for sale anywhere, unless I bought an entire truckload of coke.

A cupola is a large, messy, labor intensive affair.
An oil fired furnace will do the same thing that a cupola will do, but the oil furnace can be operated by one person easily.
A cupola can produce a considerable amount of molten iron once it gets started, simply by continuing to feed coke and scrap iron in the top.

Running a cupola to melt iron is a bit of an art.
I have seen it done, but have not tried it myself because I can't find a source for coke.
I have seen some fail at getting the cupola going, and had the iron solidify inside the cupola, which creates a big problem.

Even if I could find small amounts of coke now, I would not build a cupola, because they are just too difficult and messy to operate compared to an oil burner furnace.

If the only source of fuel I had was coal, then I may try it melting aluminum.
If you had a source for coke, you could melt iron.

I burn about 2.7 gallons per hour of diesel, and I don't do that many iron melts, and so using diesel is clean (compared to burning waste oil) and not too expensive for me.

If diesel prices go too high, I will consider burning waste oil, but would wear a powered respirator to avoid the fumes.

.

Crucible size is relative.
I often use a #10, and some consider that size huge.
I have used a #30, and I have a friend who pours I think a #70.

The crucible size is roughly equal to the weight of molten aluminum it will hold, so a #10 will hold perhaps 10 lbs of aluminum (perhaps brim full), or about 3 times that for iron, or 30 lbs of iron.
Generally a brim full crucible is difficult to pour, and so you typically use a crucible that is perhaps 70-80% full.

I use Morgan Salamander Super clay graphite crucibles exclusively, and they can be purchased on ebay.
The Salamander Super can be used for any metal, but unlike most crucibles, it is ferrous-metal-rated, and also rated for iron temperatures.
I use a dedicated crucible for each metal type.

If the parts you intend to cast are small, then you could use a #5 or even smaller crucible.
It all depends on what size parts you intend to cast, with the understanding that you will need extra metal for the sprue, runners, gates, and any risers.

You can melt aluminum in a forge (a forge is sort of like a furnace laid on its side, with one end open).
No need to build a dedicated furnace if you just want to play around and melt a bit of aluminum.

The forges I have seen typically use a propane burner, but sometimes they are fitted with an oil burner.
For melting aluminum, a propane burner is sufficient.

Years ago, the trend was to put a crucible in a pit of charcoal, and burn the charcoal to melt the aluminum.
This method works, but is a bit tedious and time consuming compared to just using a propane burner.

I suppose you could burner coal around a crucible too, but I am not sure what that would do to the exterior of a crucible.
I have not seen anyone melt iron using charcoal or coal.

What I often see in the art-iron world is coke used to melt iron in a cupola.
Coke is coal heated in the absence of oxygen.
I originally though that burning coke in a cupola was a good way to melt iron, but then I tried to buy some coke, and could not find any for sale anywhere, unless I bought an entire truckload of coke.

A cupola is a large, messy, labor intensive affair.
An oil fired furnace will do the same thing that a cupola will do, but the oil furnace can be operated by one person easily.
A cupola can produce a considerable amount of molten iron once it gets started, simply by continuing to feed coke and scrap iron in the top.

Running a cupola to melt iron is a bit of an art.
I have seen it done, but have not tried it myself because I can't find a source for coke.
I have seen some fail at getting the cupola going, and had the iron solidify inside the cupola, which creates a big problem.

Even if I could find small amounts of coke now, I would not build a cupola, because they are just too difficult and messy to operate compared to an oil burner furnace.

If the only source of fuel I had was coal, then I may try it melting aluminum.
If you had a source for coke, you could melt iron.

I burn about 2.7 gallons per hour of diesel, and I don't do that many iron melts, and so using diesel is clean (compared to burning waste oil) and not too expensive for me.

If diesel prices go too high, I will consider burning waste oil, but would wear a powered respirator to avoid the fumes.

.

Have you made any posts about your furnace? interested in making one similar

 

[dazz]

...
iron sourcing. You want good cast iron. We had a good source----used flywheels from a farm implement/engine rebuilder . The iron was clean (no sand ) and good quality . Makes life easy that way
Rich

I plan to use cast iron engine blocks. They should have exactly the properties I am looking for.

 

[vederstein]

This link is to how I made my aluminum foundry from an old propane tank:

https://www.instructables.com/Aluminum-Foundry-1/
This video is the entire creation of a flywheel for one of my steam engines:

 

[dnalot]

It was a desire to try my hand at casting that got me started on making small engines. The Bottle Engine was my second engine build and is still my favorite.

Mark T