Home Foundry

[GreenTwin]

I have seen a couple of videos of people pouring into molds that were not quite dry, and I have done it myself and had molten iron splattered back on my leather jacket, and then run down inside my gloves.

Everything has to be extremely dry when you pour molten metal into it, or when you add scrap metal to a furnace.
I hold the scraps in the exhaust stream for about 15 seconds, to drive off residual moisture.

Green sand molds have water in them, so I am not sure how they don't explode.
I guess the green sand absorbs the steam that is created?

Ingot molds have to be brought up to perhaps 600 F to drive off surface moisture.
I had actually flamed my steel ingot molds with a propane torch prior to pouring iron into them, but that was not enough, and the metal just ejected itself out of the mold.

Sometimes folks use the wrong sand and refractory material for molds, and it seems that trapped moisture can expand violently.

I will post a few videos that I have found, so others can wear sufficient protective gear, and be ready should there be a moisture problem.

 

[GreenTwin]

Another ingot mold that was not heated, and thus retained a slight amount of surface moisture.

One should always avoid wearing synthetic clothes while casting metal.
I wear cotton only clothes.
Synthetic clothes will burn and be difficult to extinguish.

 

[GreenTwin]

This person posted this video, to make light of a serious topic, which is foundry safety, and so while he could have hidden his blunders, he shares them in all their glory, so that perhaps others can avoid his mistakes.

 

[GreenTwin]

And check out this video at 0:15 and also at 7:06, the guy in the center has his face mask up when the molten cast iron errupts
from the damp moulding sand.
A near miss, and very close to being a blinded casting guy.

Be safe, and be prepared.

 

[ajoeiam]

Another ingot mold that was not heated, and thus retained a slight amount of surface moisture.

One should always avoid wearing synthetic clothes while casting metal.
I wear cotton only clothes.
Synthetic clothes will burn and be difficult to extinguish.

Wool clothes will also work well.

 

[GreenTwin]

And I see a lot of youtube casters in tennis shoes, which are synthetic, and will melt onto your foot.

I see some wear leather boots, but with laces.
Laces on the boots are a no-no in the casting world.
I was using a cutting torch years ago, and a molten blog of metal went down inside my lace-up boot.
You can't get boots unlaced fast enough in that situation, and I had a 3rd degree burn on my foot.

It needs to be smooth leather boots, with the pants leg over the boot.

I wear a leather apron, and a leather jacket over that.

Most have a neck sheild hanging down off the back of the hardhat, to ward off showers of sparks and molten metal.
I need to get a neck shield.

I have been told to adhere to the waterfall approach, which is if it is raining molten iron, will the iron run off of your leathers and hardhat, or will it find its way into an open spot? There should be no open spots.

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[ajoeiam]

And I see a lot of youtube casters in tennis shoes, which are synthetic, and will melt onto your foot.

I see some wear leather boots, but with laces.
Laces on the boots are a no-no in the casting world.
I was using a cutting torch years ago, and a molten blog of metal went down inside my lace-up boot.
You can't get boots unlaced fast enough in that situation, and I had a 3rd degree burn on my foot.

It needs to be smooth leather boots, with the pants leg over the boot.

I wear a leather apron, and a leather jacket over that.

Most have a neck sheild hanging down off the back of the hardhat, to ward off showers of sparks and molten metal.
I need to get a neck shield.

I have been told to adhere to the waterfall approach, which is if it is raining molten iron, will the iron run off of your leathers and hardhat, or will it find its way into an open spot? There should be no open spots.

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I think I would be wearing leather work boots and would try to find some spats.
Any good source for a leather apron?
Leather jackets - - - -similar to the ones for welders?
Have you ever found something that could function like a neck shield?
I'm a wondering if a boot spat might work - - - or two stitched together.

 

[GreenTwin]

I bought my jacket from a welding suppy store.
That is probably where I got the apron too.

Some wear the silver-coated stuff, or the chemically-treated clothes, but I prefer leather everything.

Many wear boot spats, but if your boots are not lace-up, you don't need spats.

I have seen some attach a leather flap to the back of the hardhat, and others just put a neckerchief over their head under the hardhat, and let the neckerchief hang out over the jacket collar.

The welding supply places have face shields that fit onto most hardhats, and that is what I use.
For iron work, the IR emitted is very intense, and so I use a shaded face shield and shaded glasses, to prevent sunburn in the eyes.

And I use leather welding gloves.
With iron work, you need sheet metal shields on the various tools, to prevent the gloved hand nearest the furnace or crucible from overheating.

Lifting the crucible out of the furnace is done as quickly as possible.

The furnace is open, and you are getting the full radiant heat from the furnace walls and from the crucible, so one does not want to dilly-dally around.

I use a glass shelf from an old refrigerator to lean over slightly to peer into the opening in the furnace lid (to check on the progress of the melt).
Without the glass shelf my faceshield begins to melt in seconds.

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[GreenTwin]

For the larger crucibles such as a #30, I use a crane and pouring cart.
This is a video from my very early days of casting, and this was a very sloppy pour, and an interrupted pour (never interrupt the pour).

 

[GreenTwin]

This was a good clean lift and pour.

 

[57mm_M18]

I have watched a lot of videos of casting brass, aluminum and iron on this blog & it makes my skin crawl in some cases. I have not commented in the past but, when I see individuals wearing sport shoes, sandals & lacking even the simplest of protective eye wear it makes my skin crawl. First, and foremost is the number of times I see someone filling molds with these hot metals while the mold is sitting on a concrete floor. This is strictly forbidden in all the foundries I have worked. Sand floors in and around the furnaces & pouring floor is a must. Concrete will explode due to the retained moisture in it, I don't care how old it is. This will turn the molten metal into molten projectiles. Second the use of protective clothing and face wear. Third, and uncluttered pouring floor with a shovel and piles of sand if a mold happens to breach. You cover the molten escaping metal with dry sand to contain the problem. Each one of the metals that we use to make our projects has its hazards. Learn what they are and treat them all with the respect they require.

Most molds breach because of improper sand formulation or improper venting & design. Those who attempt to pour high temperature metals should first understand how a mold is made. I have not seen the use of weights being used on the green sand molds in most of the videos. Most molds breach due to improper venting. The trapped steam causes the mold to break apart. The mold is more than just a container with a net shape of some part. All these little things add up to success or failure. Be safe and do a deep dive into this skilled trade so you don't injure yourself or others.

CW

 

[GreenTwin]

I have watched a number of backyard pouring videos on youtube, and I agree, many if not most make me cringe too.
The backyard folks often pour metal in tennis shoes, with little or no protection, synthetic clothing, etc.
And they often pick up their crucibles at the top by a pair of channel locks, or something similar, which is a very bad idea.

"Concrete will explode due to the retained moisture in it, I don't care how old it is."

I have heard this statement over and over again, and I know from experience that it is false.
I have spilled aluminum, brass, bronze, and iron on my concrete driveway perhaps 20 or more times, and no explosions.
I know a fellow who has poured literally tons of iron in Australia on a concrete floor, with many spills, and again, no explosions.
So while it may be a good idea not to pour over concrete, since it can explode in some cases, to say that "All concrete will explode" is a myth, and I know that from experience.

I don't use sand around the foundry area since it gets tracked everywhere, and the sand will get wet when it rains, and retain moisture, which can explode if you spill molten metal on it.
It is not a big deal if you break a mold during a pour. There is nothing that is going to happen; one does not need to panic and start throwing sand around. Just stop pouring and move to the next mold.
Again I speak from experience.
Throwing wet sand on molten metal will cause an explosion, and most of the sand I see laying around outdoors is wet.
I never let any sand get near my foundry area (other than the sand molds).

Most molds breach because of improper sand formulation or improper venting & design.

Almost all of the mold breaches I have seen have been caused by a lack of weight on top of the mold/flask.
The bouyant force of the metal on the cope (the cope contains the top half of the mold) lifts the cope and separates it from the drag (the drag contains the lower half of the mold), causing the molten metal to drain out of the cope mold.
I witnessed one vertical mold that breached with iron because the steel straps failed due to the heat.
If the top of the mold is weighted correctly, the mold won't breach unless you have done something really wrong, which is possible/probable on youtube.
It is pretty safe to say that you should never do 98% of the backyard casting stuff that you see on youtube.

Most molds breach due to improper venting.

Some molds fail due to the sand being too wet, in which case you get an explosion/eruption.
I have never seen a mold fail due to improper venting, and if you watch luckygen1001 on youtube (who has poured tons of iron), he shows that he never vents his molds, and says mold venting is totally unnecessary.
I do vent the high spots on my molds because I use resin-bound sand that does trap air.

The trapped steam causes the mold to break apart.

The trapped steam causes the mold to explode because too much water was mixed into the sand, or in the case of a resin-bound sand mold, the mold was not flamed with propane, or left outside overnight and absorbed moisture.

Be safe and do a deep dive into this skilled trade so you don't injure yourself or others.

I absolutely agree with this 100%.
There are many hazards associated with casting metal of any type, and one must completely understand the hazards, and be fully prepared for a worst-case scenario.

Some extremely dangerous things I have seen on youtube, more than once:

1. Folks operating a furnace using a propane burner, inside of a garage.
I saw one video of a guy lifting a #16 crucible and the tongs slipped, spilling the entire contents of molten metal onto the garage floor.

2. Folks operating a furnace with one or more propane bottles very close to the furnace.
This is a very good way to leave the earth quickly, and leave a huge crater in the ground.

3. Folks spilling hot metal onto their rubber propane or oil lines.
One guy ended up with an ocean of fire in his backyard.
I think he was using kerosene or some relatively flamable fuel.
I have not seen diesel spread like this if spilled, which is one reason I use diesel.
I also am working on a metal sheath to cover my fuel and air lines, and I need to finish this task.

4. Folks not using a full face shield.

5. Folks using Rube Goldberg combination lifting tongs and pouring shank.
You may be able to get away with using combo tongs/shank with light aluminum pours, but for heavier pours, the combo unit is downright dangerous to use.

6. Lifting the crucible by the upper lip using channel locks, and pouring the metal also using the channel locks.
This is a disaster waiting to happen.

7. Folks operating a furnace right next to their house (I did this in the early days, due to sheer ignorance; don't repeat my mistakes).
The furnace, molds, and fuel tank(s) should all be well away from the house, cars, and anything flamable.
If everything goes wrong, and it all goes up in flames, that should not be a problem at all, since you should not be near anything flamable.

8. Folks using plastic or rubber components on a furnace, or very near a furnace.
Anything rubber or plastic within about 10 feet of a furnace (especially an iron furnace) sooner or later will catch fire.
I use steel caster wheels, and run my pouring cart wheels on bare steel rims (no rubber tires).

9. Folks trying to operate a furnace burner without any knowledge of how to safely operate a burner.
One guy reported that his burner did not work well at all, and said "That burner design is crap", after he launched his furnace lid over the top of his house. The burner he used is the same burner that many of us use, and there is nothing wrong with the burner design, and everything wrong with his lack of safety and knowledge of how to operate burners.
It is shocking how many backyard casting folks never learn how to correctly adjust their burner.

10. I would have to say that burner safety is probably the most critical item with a backyard foundry.
I have seen so many folks mount their cutoff valves right next to the furnace, which is the last place you want to have to reach when things are going wrong.
The heat from the furnace can also melt the parts in valves.
I use remote valves for fuel and oil, and I can turn the fuel off in a fraction of a second.
I always am ready to turn off the fuel, and I make sure it is within easy reach.

11. Keep your fuel tank well away from the furnace.
You should never have a situation where an out of control fire in a furnace can reach a nearby fuel tank.
Have a shut-off valve at the fuel tank.

12. Never use concrete as a refractory material to make a furnace.
There is one video out there (I need to find that), where someone's entire furnace explodes violently as it heats up.

13. Never use uncoated ceramic blanket as a furnace interior.
The airborn fibers can do permanent lung damage.

I lay out all of my equipment before I start the furnace, and I actually do a dry-run before I light the furnace, and choreograph every step, opening the furnace lid, lifting out the crucible, setting the crucible in the pouring shank, lifting the crucible and doing a fax pour over the mold, and shanking the pouring shank with the crucible upside down to make sure the crucible is securely locked into the shank.

I often hear "You should NEVER operate a foundry at night".
The temperatures in the mid-south along with the humidity pretty much mean that you will have a heat stroke during a summer pour.
I don't fear night pours; basically all of my pours are at night; I fear heat strokes, and you can overheat very quickly with full leathers on.
What I fear is folks operating a foundry who don't know what they are doing, during the day or night.

The dry run also is to make sure your equipment is layed out so you don't trip over anything, and everything you need such as lifting tongs, skimmers, pouring shank, etc. is in the right place and easily accessible, without being a trip hazard.

I basically use something similar to the work triangle in a kitchen, which is a defined area where I will work and handle metal.
I generally don't stray out of this area during a melt.
I don't leave the furnace while it is running.

Often I see people panic if something goes wrong (illustrated well in one of the above videos).
Panic is what will get you hurt.
You must remain calm at all times, and always keep in mind the fuel cuttoff valve location.
Have a backup fuel cutoff valve at your fuel tank.
Have a clear escape path away from the furnace, and behind where you sit/work.

Make sure your crucible retainer works well.
My first retainer design did not work well, and a full crucible of iron spilled right out of the shank (onto the concrete driveway) just as I began to pour (the concrete did not explode). I am not advocating that others pour over concrete, but I am just saying it is not necessarily the disaster that I keep hearing about over and over again.


Just a few thoughts.
Be safe.
Wear lots of safety gear, and expect the unexpected.
When in doubt, err on the side of caution.

Have several backup plans.
The first backup plan is to quickly back away from the danger, and then immediately turn off the fuel.
Don't do anything foolish that will make the problem worse, such as throwing something damp or wet into the inferno.

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[GreenTwin]

Here is a video about what can happen with concrete when heated.

 

[GreenTwin]

The guy in this video says its a complete mystery as to what happened in his fire pit.

He built a fire on top of damp concrete, and it exploded.

 

[GreenTwin]

Don't pour molten metal down a wet anthill, and don't have your propane tank right next to your burner.

 

[GreenTwin]

Here is the video I was looking for.
Guy used concrete as a furnace refractory (never do this).

Furnace refractory (I use Mizzou) must be dried out slowly to drive out the moisture, and not overheated while is still has moisture in it.

 

[GreenTwin]

This guy has some good backyard foundry safety tips.
I can't begin to cover all backyard foundry safety, and I am not going to try.

Some good ideas in this video.

 

[ajoeiam]

This guy has some good backyard foundry safety tips.
I can't begin to cover all backyard foundry safety, and I am not going to try.

Some good ideas in this video.

Thank you for sharing your experiences and information that you have gathered.

Greatly appreciated here!!!

 

[GreenTwin]

I a glad to share, and hope others can get into the hobby, or improve their methods perhaps if they are already in the hobby (we have several very talented backyard casting folks right here on this forum).

I got into backyard casting out of a desire to find a better method to build model engines.
The bar stock method I tried was very hard on my inexpensive lathe and mill, and the results were not even close to what I was looking for as far as appearance, accuracy, athenticity, etc.

I started reading about backyard casting in 2011, and decided to take the plunge after I ran across a website called backyardMetalcasting.
https://backyardmetalcasting.com/
The fellow who ran the above backyard website also sponsored a forum called Alloy Avenue, and so I began to read about how various folks created their foundries.
I basically read every single post on that forum for years (thousands of posts).

I paid very close attention to what worked, and what did not work, and in particular I studied all of the iron furnaces and methods.

Unfortunately the Alloy Avenue forum stopped working a year or so ago, and a lot of information was lost.

So I have been casting metal, including gray iron, for over 10 years now, and I enjoy the backyard foundry work as much as any hobby I have been involved in.

I have talked with folks who worked in steel foundries, to see how the big mills make iron and steel.
I have also attended a number of art-iron events, where they use cupolas to melt iron, and had extensive discussions about how to best melt and cast gray iron.

I also chat frequently with a buddy of mine who started his own iron foundry a few years ago.

The king of gray iron backyard castings (in my opinion) is a guy from Australia, who goes by "luckygen1001" on youtube.
This fellow has shared a lot of his casting knowledge with me and others, and his gray iron castings are pretty much unparalleled from what I have seen in the backyard world.
https://www.youtube.com/user/luckygen1001/videos
The best aluminum casting guy I have seen is called "olfoundryman" on youtube, also from Australia (these guys know each other).
This individual use to work in a foundry as the metalurgist, and he really knows his stuff about the professional foundry business.
https://www.youtube.com/channel/UC90RoN_IjSRF18jAG0HIA6g/videos
I agree with most of what these two guys say, and have learned a great deal from both of them.

Another fellow I watched early on is called "myfordboy" on youtube, from the UK (the "myford" name comes from the UK lathe manufacturer, not the auto company).
Myfordboy has is own style of casting methods and equipment, and while I don't prescribe to much of how he does his foundry work, nobody can deny that this fellow is an extremely talented backyard casting person, and a prolific backyard casting video producer.
Myfordboy's engines speak for themselves, such as his custom-cast Ball Hopper Monitor, and other engines.
https://www.youtube.com/c/myfordboy/videos
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[GreenTwin]

There are a large number of what I call "weekend warrior" foundry burner and casting guys on youtube, and it is pretty safe to say that you should ignore virtually every one of them and their equipment.

Everyone wants to make that "better mousetrap" burner, and so you see the most bizarre burner designs, many or most of the being terrible designs for use with a foundry furnace.

Many of the casual backyard folks build furnaces with hardware-grade materials, and homemade refractory, and these furnaces often only last for a few melts with aluminum.

One big trend these days is to melt aluminum cans, and pour ingots.
Aluminum cans make a very poor grade of aluminum for engine work.
For engines, AL356 should be used.

I must say I was as proud as any human of my first aluminum ingot.
It was like stepping onto the surface of the moon for me.
I still have one of those ingots.
But if you want to cast engine parts, don't get stuck in "ingot land".

Some folks make their own crucibles.
I did use a welded steel crucible in the beginning and I must say it worked pretty well, but eventually the steel will fail, and you will have a molten metal spill.
These days I exclusively use Morgan Salamander Super clay graphite crucibles for all metals (a separate crucible for each metal type).

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