How not to Do Backyard Metal Casting

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A good number of foundry men, wear "safety flipflops".
I am lucky that I do not have to work under conditions like this.


In contrast:

.... self exploitation in the spare time ... a common practice by many of us ( I try to remind myself to treat myself, as I want to be treated by others )

(nothing I do makes any sense :cool: )


But at least they make a living with their own hands and support their families within their abilities and circumstances.
Huge difference between trying to make a living and proving stupid - like the guy in the first video !!
 
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But at least they make a living with their own hands and support their families within their abilities and circumstances.
Huge difference between trying to make a living and proving stupid !!
No intend to blame the workers. I was not trying to point fingers or be malice. Possibly they do not have much of a choice.

I see it just is a reminder, for myself (maybe others), that I have choices and should not work below my own risk awareness.
 
Possibly they do not have much of a choice.

In my country, the current situation is probably a little better than theirs, but I understand why they have to do it that way.
I don't support and I don't agree with the way they do things, but if I were put in that situation, I probably wouldn't have any other choice. ;)
 
You can get away without using a lot of safety gear if you not in a position to have it.
You just have to be very careful about what you do and how you do it.

The main things that get neglected are eye and lung protection, and those are critical items that cannot necessarily be fixed if you don't protect them.
There is a lot of IR that you need shaded glasses for if you are exposed to much of that.
The sand can also cause problems if you inhale that on a daily basis.

.
 
And almost no health care either , in a country that has landed a vehicle on the moon ! when Russia failed.
 
In 1960, I worked in a small iron foundry in northern Illinois during my summer break from college. There were a couple of veteran foundry men who liked to impress visitors such as salesmen. On occasion when the cupola was tapped for the days' pour, one of them would ask the other if it was hot enough. The other man would say "I don't know, let me check. He would then go over to the stream of molten iron going in to the crucible an proceed to wet his finger and run it through the 2 inch stream and flip molten across the floor with his finger! All I remember about safety was I was told not to wear any jewelry. The permanent founders all had slip on ankle high leather shoes that could be taken off with a flip of the wrist. No OSHA in those days.
 
The pre-OSHA days were pretty wild, as were the pre-EPA days.

They did a lot of damage in this area dumping toxic chemicals on and in the ground in this area, and contaminating the water table in some places.

Now days they sometimes seem to go too far in the extreme with OSHA and EPA.

One town located on a beach decided that foundry sand was toxic, and they were getting ready to ban all sand.
Someone reminded them that there were millions of pounds of sand just yards away on the beach, so they backed off.

And OSHA safety gear can be so cumbersome that it creates a hazard by itself.

Some good things that OSHA has done is put those plastic mushroom caps on the ends of rebar.
That was very much needed.

Hardhats are a good thing.

The safety harness may or may not be more safe in some situations.
I can climb a lot better without a harness and strap, but I see where they are coming from.

They shut down a big foundry in town years ago, and then they found out that they had been dumping old foundry sand out the back door for years.
They put a clay cap over the sand, and put in some monitoring wells.
You would think that the site was the most toxic place on the face of the earth, and if you disturb the clay cap in any way you would be fined into oblivion.
Relatively speaking, used foundry sand is not very toxic in my opinion.

.
 
Foundry men wear special shoes, with the tongue designed so there are NO holes penetration that could permit molten metal splashes to get into the boot to hurt flesh. Welders often say they have had foot burns from a bit of molten slag dropping down into a boot. But foundrymens boots avoid that as well.
Not got any. Wish I had...
K2
Wear spats. The versions made for foundry/welding cover the boot laces.
 
This is the same type of pop I had, but mine was iron.
I did not panic, but I had some burns on the hands before I could get the gloves off.



Per heat everything slowly.
I would start with furnace for a hour before starting so had no blow outs.

Dave
 
There are a lot of "experts" out there, and the problem is that often times they give incorrect advice, or make false assumptions.

I have debunked many "accepted rules" in metal casting, and have found out that very few people know what they are talking about when it comes to foundry work. I have found many "accepted rules" to be false.

Once a good myth gets started, and spreads across the internet, it is pretty much impossible to convince folks otherwise, even if you can demonstrate it to them.

Several myths I have seen, which have proven to be incorrect in actual use:

1. Crucibles need to be heated slowly to drive off moisture, and so as not to damage the crucible.
If you keep your crucibles in a dry spot, and use a quality crucible like a Morgan Salamander Super, you don't need to heat it slowly.
I turn my burner on at 100% with the fully charged crucible in the furnace.
This is not a problem.
You can ramp up your burner slowly if you desire, but it is not necessary if you are using a qualit crucible and refractory.

2. Never pour metal over concrete.
I and others who have done a lot of iron casting have always poured over concrete, and have spilled significant amounts of molten iron on it.
I got one minor spalding of the concrete, but no explosions. Ditto with my fellow casting guy in Australia, who has poured tons of iron.
What causes explosions with molten metal is water or moisture.
Most folks recommend pouring over sand, but sand will have moisture in it, and a spill on damp sand is likely to cause the explosion you are looking to avoid.
Needless to say, don't pour over wet or damp concrete, such as after a recent rain.

3. Sand is toxic.
Sand is not toxic, but do not inhale the dust from sand, since that can ruin your lungs.
Breathing dust of any kind can damage the lungs, so in general, do not inhale any type of dust or fibers.

4.
You can use a combination lifting tong/pouring shank, and avoid having to use two tools.
This may be true with very lightweight pours, but is a very bad idea with heavier metals like brass/bronze and iron.
The combination tong/shank puts you at a huge disadvantage as far as the handle trying to twist out of your hand.
The weight of the crucible and metal at the end of a bend shaft produces a large amount of torque that you have to fight against.
People promote the combination lifting tong/pouring shank because they think it makes them look like they have created a clever gadget (lots of youtube views generated) when in fact this sort of device only works for very light pours.
You have a great deal more pour control (which you absolutely need to control metal velocity) if you use a well balanced pouring shank (not a combo unit).
The centerline of the pouring shank should put the weight of the crucible and metal at a neutral point, so that you are not having to lift weight as you try to pour.
The easiest way to control a pouring shank is to add a handle to the end of it that sticks straight down.
You should not have a pouring shank handle that puts your wrist in a strained position during the pour, since this will make controlling the pour very difficult.


5. If the saleman says a crucible is "iron-rated", then it must be rated for use with iron.
One guy who got into iron casting a few years ago purchased an "iron-rated" crucbible (according to the salesman), and once it reached molten iron temperature, it folded up like a wet waffle in a very dangerous way, spilling the entire molten iron contents into the furnace interior.
Your safety depends on you using a good quality crucible that is rated for the metal you are using, and also rated for the temperatures that the crucible will be exposed to.
A Morgan Salamander Super is "ferrous-metal-rated", and rated for 2,900 F, which is more than adequate for iron work.
Morgan's silicon carbide crucibles (be careful, some of them also have the word "Salamader" in them) are not ferrous-metal-rated, and thus are not rated to be used with iron. Silicon carbide crucibles generally have a much lower maximum operating temperature rating than their clay-graphite Salamander-Super crucibles.


Anything that is used in or around molten metal must be preheated to drive off moisture.
This is not a myth, but an absolute truth that should never be neglected.
Any scrap metal that is going to be used must be held in the furnace exhast stream for at least 30 seconds minimum, to drive off residual moisture.
You cannot see residual moisture on the surface of metal, but trust me, it is there.
You need to also preheat lifting tongs, charging tongs, stiring rods, skimmers, and anything else that will come in contact with molten metal, or come in contact with a red hot crucible.
You should never drop a crushed aluminum can into a crucible of molten aluminum, since a crushed aluminum can can easily trap moisture.

I have seen numerous metal exposions when people pour into sand molds that have excessive moisture in them.
Cores should be baked or lightly flamed with a propane torch to drive off moisture.
I lightly flame my resin-bound molds, also to drive off moisture, and to burn off any uncured resin.

There has been a lot of discussion about not shocking a crucible with a sudden temperature change, and this is true.
Turning on the burner at 100% when starting the furnace does not really shock the crucible or the furnace, since the furnace and crucible mass are significant, and it will take time to begin to heat them.
Sudden temperature changes can cause micro (or large) cracks in the crucible.
I put the crucible back in the furnace after a pour, and close the lid, to let the furance and crucible cool down slowly.

If you are using lightweight refractory such as insulating fire bricks, you may want to baby those, since they don't take abuse well at all, compared to a dense refractory like Mizzou which will take a lot of abuse and will also stand up to repeated iron slag splatters.

.
 
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Having been around a variety of foundries, - including iron - I think Green Twin's comments are excellent advice.
Having choked on "nasty gases" in one foundry, I would also caution about "unseen killers" - The exhaust gases from burners, and furnaces, gases given off from resin burning in moulds, etc. Some have a bad taste or smell, others simply make you choke. Some like CO2 and Carbon monoxide are undetectable by humans and simply kill.
My choking experience was walking past a crucible set near horizontally, that had a gas blow-torch heating it by the flame directed inside , and exhaust emitting horizontally - so the exhaust gas stream was blowing across the walkway. The foundry guide told me the workers knew where the nasty gases were so held their breath when walking past such gas streams!
An extract from a study:
"EACH YEAR, unintentional carbon monoxide (CO) poisoning is estimated to cause approximately 2100 deaths in the United States and is a problem in other industrialized countries as well. Efforts to educate the public on how to prevent CO poisoning have focused mainly on increasing awareness of the dangers of CO and on promoting the proper maintenance of potential residential sources of CO, such as furnaces and water heaters." - For "furnaces", you can add any indoor combustion - such as a gas or oil burner in an enclosed area.
https://emj.bmj.com/content/17/1/38And on CO2:
"Symptoms of mild CO2 exposure may include headache and drowsiness. At higher levels, rapid breathing, confusion, increased cardiac output, elevated blood pressure and increased arrhythmias may occur. Breathing oxygen depleted air caused by extreme CO2 concentrations can lead to death by suffocation."
1 litre ( about 0.8Kg.) of diesel fuel produces 2.6 Kg. of CO2. Air contains about 0.75gms/cubic metre.
OSHA has established a Permissible Exposure Limit (PEL) for CO2 of 5,000 parts per million (ppm) (0.5% CO2 in air) over an 8-hour work day. That is equivalent to 6gms per cu m. So that means if you burn 1 litre of fuel, you need a space (fresh air passing the exhaust) of 4300cu.m. - Seems HUGE to me: That's an air change of a room 50ft cubed = a factory building, every hour. That's a hell of a lot of fresh air to dilute the burner exhaust. SO: out-of-doors seems to be a "must", and maybe a hood and chimney or flue to carry the vented exhaust from above the furnace to "outside" the workplace/furnace/casting area? A flue accelerates the rising gases so they shoot higher before cooling and falling down where you are working, so are better diluted...
Remembering of course that CO2 is heavier than air, so when cooled, the furnace exhaust can collect in nearby basements, etc. a 4% concentration of CO2 is lethal. 0.2% of CO is lethal. So the gas coming out of the furnace is lethal (more than 20% CO2). Fortunately it is too hot to breathe! - DO NOT attempt to breathe it!
Surely a CO detector alarm is a must? I have one in the garage, and have set it off even when brazing a job with a gas blow-torch, even though the garage door was open, and my hearth is adjacent to the opening. (The hot gases rise and the CO alarm is on a shelf over my head, so it gets the worst gas before I do!).
Stay well ventilated and safe and enjoy many years of whatever you enjoy!
K2
 
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CO can be a real problem, and is why I don't melt any metal indoors with a burner.

Another thing I run into in industry is low oxygen.
I sometimes have to enter large wet wells, pipe tunnels, etc., and in the old days, we just felt for some ventilation air flowing, and then went in.
These days I am much more wise about low oxygen and other stuff in the air, and they have some good inexpensive monitors you can wear on your lapel.

I go into these spaces with multiple people wearing multiple monitors.

.
 
There are a lot of "experts" out there, and the problem is that often times they give incorrect advice, or make false assumptions.

I have debunked many "accepted rules" in metal casting, and have found out that very few people know what they are talking about when it comes to foundry work. I have found many "accepted rules" to be false.

Once a good myth gets started, and spreads across the internet, it is pretty much impossible to convince folks otherwise, even if you can demonstrate it to them.

Several myths I have seen, which have proven to be incorrect in actual use:

1. Crucibles need to be heated slowly to drive off moisture, and so as not to damage the crucible.
If you keep your crucibles in a dry spot, and use a quality crucible like a Morgan Salamander Super, you don't need to heat it slowly.
I turn my burner on at 100% with the fully charged crucible in the furnace.
This is not a problem.
You can ramp up your burner slowly if you desire, but it is not necessary if you are using a qualit crucible and refractory.

2. Never pour metal over concrete.
I and others who have done a lot of iron casting have always poured over concrete, and have spilled significant amounts of molten iron on it.
I got one minor spalding of the concrete, but no explosions. Ditto with my fellow casting guy in Australia, who has poured tons of iron.
What causes explosions with molten metal is water or moisture.
Most folks recommend pouring over sand, but sand will have moisture in it, and a spill on damp sand is likely to cause the explosion you are looking to avoid.
Needless to say, don't pour over wet or damp concrete, such as after a recent rain.

3. Sand is toxic.
Sand is not toxic, but do not inhale the dust from sand, since that can ruin your lungs.
Breathing dust of any kind can damage the lungs, so in general, do not inhale any type of dust or fibers.

4.
You can use a combination lifting tong/pouring shank, and avoid having to use two tools.
This may be true with very lightweight pours, but is a very bad idea with heavier metals like brass/bronze and iron.
The combination tong/shank puts you at a huge disadvantage as far as the handle trying to twist out of your hand.
The weight of the crucible and metal at the end of a bend shaft produces a large amount of torque that you have to fight against.
People promote the combination lifting tong/pouring shank because they think it makes them look like they have created a clever gadget (lots of youtube views generated) when in fact this sort of device only works for very light pours.
You have a great deal more pour control (which you absolutely need to control metal velocity) if you use a well balanced pouring shank (not a combo unit).
The centerline of the pouring shank should put the weight of the crucible and metal at a neutral point, so that you are not having to lift weight as you try to pour.
The easiest way to control a pouring shank is to add a handle to the end of it that sticks straight down.
You should not have a pouring shank handle that puts your wrist in a strained position during the pour, since this will make controlling the pour very difficult.


5. If the saleman says a crucible is "iron-rated", then it must be rated for use with iron.
One guy who got into iron casting a few years ago purchased an "iron-rated" crucbible (according to the salesman), and once it reached molten iron temperature, it folded up like a wet waffle in a very dangerous way, spilling the entire molten iron contents into the furnace interior.
Your safety depends on you using a good quality crucible that is rated for the metal you are using, and also rated for the temperatures that the crucible will be exposed to.
A Morgan Salamander Super is "ferrous-metal-rated", and rated for 2,900 F, which is more than adequate for iron work.
Morgan's silicon carbide crucibles (be careful, some of them also have the word "Salamader" in them) are not ferrous-metal-rated, and thus are not rated to be used with iron. Silicon carbide crucibles generally have a much lower maximum operating temperature rating than their clay-graphite Salamander-Super crucibles.


Anything that is used in or around molten metal must be preheated to drive off moisture.
This is not a myth, but an absolute truth that should never be neglected.
Any scrap metal that is going to be used must be held in the furnace exhast stream for at least 30 seconds minimum, to drive off residual moisture.
You cannot see residual moisture on the surface of metal, but trust me, it is there.
You need to also preheat lifting tongs, charging tongs, stiring rods, skimmers, and anything else that will come in contact with molten metal, or come in contact with a red hot crucible.
You should never drop a crushed aluminum can into a crucible of molten aluminum, since a crushed aluminum can can easily trap moisture.

I have seen numerous metal exposions when people pour into sand molds that have excessive moisture in them.
Cores should be baked or lightly flamed with a propane torch to drive off moisture.
I lightly flame my resin-bound molds, also to drive off moisture, and to burn off any uncured resin.

There has been a lot of discussion about not shocking a crucible with a sudden temperature change, and this is true.
Turning on the burner at 100% when starting the furnace does not really shock the crucible or the furnace, since the furnace and crucible mass are significant, and it will take time to begin to heat them.
Sudden temperature changes can cause micro (or large) cracks in the crucible.
I put the crucible back in the furnace after a pour, and close the lid, to let the furance and crucible cool down slowly.

If you are using lightweight refractory such as insulating fire bricks, you may want to baby those, since they don't take abuse well at all, compared to a dense refractory like Mizzou which will take a lot of abuse and will also stand up to repeated iron slag splatters.

.
(Normally don't include all the quoted text but am this time - - - apologies if that offends someone!!)

This is the kind of reading that I find so incredibly useful!
Someone that has shown that they're doing the stuff and then they're telling about what to watch for in the doing.

IMO - - - I'm getting to learn from their experience (am I allowed to say - - - from their mistakes) so that its far less likely that I'm going to do things that may harm me.

Thank you sir for sharing - - - especially all the details - - - - I have far too many irons in the fire right now but you are making casting more and more appealing!

A serious pile of bouquets from here!!!!!!!!!!!!!!
 
GENERAL OVERVIEW OF FOUNDRY WORK BOOK

Thanks, I am more than glad to share what I know.
It took me at least six years to sort out all the furnace, crucible and burner options, and find out what a good combination is.
It took me a few more years to learn how to correctly operate an oil-fired furnace.
There is no reason for it to take anyone six years in order to learn the process.
I know of one guy who had a mentor at a foundry, and he set up an iron foundry and was successfully casting iron within a month of starting.

Here is one book I ran across in 2011, written by a mechanical engineering student, who I have lost contact with.
While this book is not perfect, it is a pretty comprehensive book about metal casting.
I had comments at one point about how this book could be improved, but have lost those.
I need to go through this book again, and comment about how to do gray iron pours, and a few other things that can be better done.

This book is good about covering the fundamentals of backyard casting in a wide overview.

http://prometheus-foundry.com/The Hobbyist's Guide to Casting Metal--2nd Edition (web).pdf
.
 
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CUPOLAS

I started trying to cast things in 2011, and many people recommended building a cupola (or cupolet, which is a cupola with a lid).

I have seen many cupolas in action in the art-iron community, and they work well, and can produce large amounts of iron.

I got excited, bought a cupola book, and then started looking for a fuel source.
The fuel for a cupola is "coke", which is coal heated in the absense of oxygen.

I could easily buy a semi-truckload of coke, but not a small amount.
I looked high and low, but could not find a source for a small amount.
I asked the local art-iron folks "Where the heck do you get your coke?".
They said "You have to know someone in the coke industry".

I decided to look at other furnace types, which turns out to have been a wise decision, since I have since learned that cupolas are very labor intensive, large, and messy. Cupola's are best for art-iron events, where you need to melt a thousand pounds of iron or more during a short period of time, and fill perhaps hundreds of molds during the event.

.
 
OIL BURNING IRON FURNACES

I ran across this website from a guy who was very active in backyard casting, and then vanished from the face of the earth apparently, never to be heard from again.

https://backyardmetalcasting.com/
Note: I would recommend not attempting to purchase anything from this site, based on comments received from others about non-response.

This was the actual page that got me excited about casting engine parts in gray iron, and this page proved that it could be done in a relatively primitive backyard setting.

https://backyardmetalcasting.com/ironcasting01.html

There is a ton of information on this website, and sorting through all of it took some time.
Some of the information is good, and in some cases, there are better ways to do things.

.
 
OIL BURNERS

There are a multitude of burner types out there, and basically a cult-like following of what I call "hot tube" oil burners.

Without going into a lot of detail, you should avoid all hot tube oil burners for foundry work.
Hot tube oil burners are basically only useful for getting millions of ytube views, and shooting out huge flames like a flamethrower.

A varian of the hot tube oil burner is a burner made from refractory, which I call a "pre-combustion" oil burner.
This burner is generally called an Ursutz style, named after the guy who patented it (patent attached).

In the backyard casting world rush to build a better mouse trap, I have seen folks build Ursutz type oil burners.
The problem with them is that if they are made of carbon steel, or stainless steel, they will relatively quickly errode, and can fail in a very dangerous way.

The idea is to get the air/oil mixture burning before it gets into the furnace, and thus obtaining a much higher temperature from the output of an Ursutz.

Its a great idea in theory, but a bad idea for backyard foundry furnaces.

The problem is that crucibles, refractory, etc. are generally rated in the 3,000 F - 3,200 F range for continuous use.
An Ursutz can produce a temperature far higher than that range, and thus it can damage the crucible and the furnace refractory.

A buddy of mine uses a Ursutz-style oil burner, and he complains constantly about high quality crucibles only lasting a few pours, continuous plinth failure (the crucible sits on top of a round platform called a plinth, that elevates the crucible into the hotter region of the furnace), and frequent refractory failures which require expensive furnace rebuilds.

A hot tube oil burner is like a mini-Ursutz.
In spite of the cult-like believers on ytube, you should never use a hot tube oil burner for a backyard furnace.
There are no benefits, and a multitude of disadvantages.

US2387420-0.png
 
I doubt I'll get into backyard foundry work, but I am intrigued by the high tech "right way" for furnaces, crucibles etc.
All I was taught at school was stick a crucible of scrap aluminium in the fire bricks of the brazing hearth, then cook it with the gas blowlamp until the metal melts. Then pour it into the mold that teacher made.
Seeing an iron foundry was a real eye opener.
The cylinder head casting line at work was different again.
But none of those relate to the home foundry, so I have enjoyed this thresd.
Thanks.
K2
 
When I started trying to cast metal (aluminum was my first successful crude test casting), I wanted to cast engine parts in gray iron.

Generally speaking, in the model engine circles, I was told the following:

1. I has not been done yet on a hobby level.
2. It cannot be done on a hobby level.
3. The intense heat will burn you if you are in the vicinity of the furnace/crucible.
4. If you do succeed in making a gray iron casting, it will have defects and hard spots, and will not be suitable for use.

At first, I somewhat tended to believe what others said.
I had no proof otherwise, and after all, these were some of the masters of model engine building making these statements, so who was I to question that, never having built an engine in my life.
I started to look for examples of other's casting model engine parts in gray iron.

Eventually I found the guy who goes by "ESC", who casts his own model V-8 engine in gray iron.
So there was proof that it could be done, and proof that complex castings could be made in gray iron on a hobby level.

Then there was the "How".
There were examples online of folks melting and pouring some nice iron pieces, but not necessarily engine parts.

Melting gray iron and getting it to a suitable pour temperature is one thing.
Making the patterns, and setting up the mold correctly is an entirely different and complicated undertaking.

My first iron pour used Petrobond (tm) oil-bound sand, and that casting had some sand inclusions where the mold failed.
Since it was my first iron casting, I repaired the holes, and used the castings.

I then experimented with sodium silicate bound sand, and finally discovered resin-bound sand.
Resin-bound sand is designed for iron and steel castings, and so that solved my sand mold problems overnight.

Then it was a matter of learning the correct sprue, runners, risers, gates, etc., and I learned that from Bob Puhakka and his mentor John Campbell.

Then I discovered ceramic mold coat, and solved my casting surface finish problems.

I learned about ferrosilicon, and how to use the critical amount (not too much) to give castings that are easily machinable with no hard spots (chills as some call them). Too much ferrosilicon causes excess shrinkage and hot tears.

I studies videos online of folks using resin bound sand.

I had to learn new ramming and molding techniques with resin-bound sand, since the traditional greensand flasks and molding techniques don't apply when using resin-bound sand.

I learned how to correctly tune an oil burner so that I could reach iron pour temperatures with good fluidity.

And I build a medium/low mass furnace, for quick heating and melting, using materials that would withstand up to iron temperatures and slag for extended periods of time.

So people ask me how I went from making initially flawed gray iron castings that had sand inclusions and hard spots, to making iron castings that rival what a commercial iron can produce.
The answer is that it was a long series of steps, as detailed above.
Like climbing a tall ladder.
You take one rung at a time.

Some don't believe I can do it.
Come over to my house, I can show how it is done and make you a believer.

In the beginning I had little confidence that I would ever figure out how to cast iron parts successfully, and I really never fully expected to figure it all out.
Many told me I would never figure it out; they were wrong, but I can't fault them for saying that, given the effort that was required to do it.

It is a awesome thing (a lifelong dream of mine) to be able to look at an old engine, make the 3D design, patterns, molds, iron castings, and finally a working model engine.
I recall looking at the steam engines in the toy shop as a kid, and asking my dad "Where can we buy a real one?".
Dad said "You can't buy them anymore".
I said "Why not ?".
He said "Just because".

So you many not be able to buy many steam engines anymore, but you can definitely make your own.

.
 
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