If you are worried about cracking, slow out the drying process. Wrap it up loosly with a damp, wrung out paper rag. After a day, re wet the rag but open a small hole in the bag. Repeat this process for a week and each time make the hole a little bigger each time and it will reduce cracking.
The grass will decompose to calcium carbonate or to calcium oxide if the temperature is high enough. Calcium carbonate melts at (+/-) 2400 F. Calcium oxide melts at (+/-) 4300 F. The hotter temperature the clay is fired at the more carbon will be driven out and the hotter the temperature the crucible will handle.
Hm good to know. I had thought about the grass mostly as a temporary structural reinforcement. I wonder what the consequences of calcium carbonate in the crucible will be. JF
I've always been fascinated by the "stone age / metal age transition period" but been too busy with other projects (or too lazy???) to experiment much.... so glad to see you two doing the experiments I haven't.... (excuse my alchemical joke) Keep up The Great Work!
I’m excited to see how this turns out. I’m currently prepping for a similar project, so I’ll probably use some of your experience for my work. I’d recommend that you fire those as hot as possible, even if it’s far beyond the operating temperatures of your final application. The hotter they are fired, the more resistant to heat shock they are. If you have any kaolin deposits near you, that would probably bump up your crucible to another level. And drying your crucibles slower should help with the cracking, if you end up trying again.
Thanks! I think the drying process could be further improved; I'm in a very dry environment so that's a factor. I will try to fire them as hot as I can, which will probably be an oxygen-fed wood fire in a semi-contained environment, so maybe 1800 degrees F as a ballpark. Good luck with yours and I hope you share! JF
Use a dolly pot amd crush some quartz rocks, also you can crush some calcium alluminate brick and add that as well, i have not made one but the science adda up adding sillica and aluminate. I will try it since here a crucible is ridiculously hard to find or buy as an individual.
Looking forward to learn from your experience. I am just about to make a ceramic holder for heating element with alumina and aluminium phosphate. They always started to disintegrate after some time...
Yooooo, I figured out putting sand in clay to make it stiffer when I was 4 lived in Georgia, just kept digging in the sandbox till I hit clay (hope it was clay)
I made the crucible and it is light and handled melting a piece of copper wire with my small butane torch. It's interesting that the thing kinda worked!
That is so f-ing bizarre. I literally did this EXACT experiment last week. I wanted to try making glass, and I had clay on hand. Tried with hay additive, beach sand and straight clay. The straight clay seemed to work the best and I'm currently drying my crucible for next weekend. The reason I'm using clay is because I wanted to try and microwave it while the glass was still molten (see Cody'slab video), and a steel or graphite crucible would be very bad in a microwave. Plus I wanted a glass cube, and I just moulded the crucible accordingly.
Think you could try making one with charcoal mixed in? Carbon stays solid up to ridiculous temperatures. Also, could you try different methods for decreasing the time it takes to dry, like using desiccants or heat and good air flow?
Carbon could replace the sand here, if it was in a form that couldn't get burned more, like ash. decreasing dry time is both possible but generally not recommended because the outside will dry at a much faster rate than the inside, which would lead to more and deeper 'checking' since the outside will shrink before the inside does.
True that without oxygen it can stay as it is, as is done with clay graphite crucibles. However this is also how expanded clay is made so unless you really know what you are doing, stay away from organics.
Have you found out how high you can fire this clay before it melts? If you're using a DIY kiln, do you have temperature cones to judge how hot it gets? Also, are you sure you want to glaze it? It seems like you'd be introducing an unnecessary variable into your melt. If you want a smooth surface couldn't you just dip it in a slip made from your clay body or burnish it?
I'll probably use a metal bar as a thermometer (color/temperature). I've heard that a glaze can be important, particularly when casting precious metals, since the pottery is porous and will absorb metal. As to how well this clay fires, well, that's what I'm here to find out. JF
Generally no. There's a lot of different kinds of stone, and the properties matter for this application. Most natural stone contains moisture, which can cause steam explosions and cause the crucible to break. Limestone breaks down in heat to become quick lime. Soapstone has decent enough properties, so it's been used traditionaly for making molds for bronze casting. But I'm not sure if it's been used for crucibles much. JB
To some extent it was but it has to be preheated and slowly brought up to temperature and they are prone to breaking, at least that's what I've heard. I make my own from clay.
Depends on the source rock and how much weathering the same has undergone. Also depends with Clay. Most of what we call Clay and sand is determined by particle size more than chemical makeup. JB
@GoodandBasic I understand what you are saying, but you are describing a clayey sand- or possibly a sandy soil, not sand on its own. Sand is just sand as in quartz grains under 2mm and over 2um in size. Its like saying glass has lead in it if you get it from a stain glass window... no it's glass. It's important because sand intrinsically has no charge- which has impacts for agriculture. Alumina is part of aluminosilicate complexes which are the building blocks of what we call clay. This has a lot of charge and also can hold water. And I'm so sorry you just happened to come across a soil scientist who was picking up on a minor point. I've spent a decade researching this, so it doesn't matter to most 😀 Google the soil texture triangle and you'll see all the available options. I hope we can still be friends!
@user-ug5sb6qg1u is the name of the best heavy metal band... Actually give it a look. A unique feature of the dirty triangle (that sounds far worse, but also is a good name for a band) and you will discover its a3d projection in 2d. It's possible to add height to it, enabling you to comprehend.... 4D ON A 2D SPACE!
There's definitely some risk, some of which comes from making my own crucible and some of which just comes from the fact that it's casting molten metal regardless of the crucible type involved. I'll be extra careful as I figure out how good these crucibles are. JF
I searched for your follow-up video, but was unsuccessful. BTW, awful video regardless. You literally did something and then said "I hope it works." What a waste of time. 1/10
Yep he did lots of surface level research but didn't watch a single youtube vid on making crucibles. This is the kind of video a 7 year old makes. No experience, and no depth of research.
If you are worried about cracking, slow out the drying process. Wrap it up loosly with a damp, wrung out paper rag. After a day, re wet the rag but open a small hole in the bag. Repeat this process for a week and each time make the hole a little bigger each time and it will reduce cracking.
Nice. We've been getting a some extra cracking on our smelt furnace and I bet it's because the temperature is rising with spring. JF
The grass will decompose to calcium carbonate or to calcium oxide if the temperature is high enough. Calcium carbonate melts at (+/-) 2400 F. Calcium oxide melts at (+/-) 4300 F. The hotter temperature the clay is fired at the more carbon will be driven out and the hotter the temperature the crucible will handle.
Hm good to know. I had thought about the grass mostly as a temporary structural reinforcement. I wonder what the consequences of calcium carbonate in the crucible will be. JF
@@GoodandBasic it works? Please reply🙏
I've always been fascinated by the "stone age / metal age transition period" but been too busy with other projects (or too lazy???) to experiment much.... so glad to see you two doing the experiments I haven't.... (excuse my alchemical joke) Keep up The Great Work!
I disliked you chemical joke, mate. You might wanna edit that out.
how did it turn out?
I’m interested to see how this holds up as a crucible. I do worry the thickness will make it prone to fracturing in the kiln.
I’m excited to see how this turns out. I’m currently prepping for a similar project, so I’ll probably use some of your experience for my work.
I’d recommend that you fire those as hot as possible, even if it’s far beyond the operating temperatures of your final application. The hotter they are fired, the more resistant to heat shock they are. If you have any kaolin deposits near you, that would probably bump up your crucible to another level.
And drying your crucibles slower should help with the cracking, if you end up trying again.
Thanks! I think the drying process could be further improved; I'm in a very dry environment so that's a factor. I will try to fire them as hot as I can, which will probably be an oxygen-fed wood fire in a semi-contained environment, so maybe 1800 degrees F as a ballpark. Good luck with yours and I hope you share! JF
This is a fun experiment I’m now invested in seeing to the end.
What about if you took charcoal and powdered it, then mixed it in with the clay?
Not for a newbie, it will cause expansion when fired
Thanks for your wonderful technical information you have shared in a short time. Really useful, from Jawaharlal Bharat 🙏
Would horsetail/equisetum not even better than grass clippings because of the Silicate?
I...think so? In theory it should, but I'm not sure at all. There is some in Utah, so depending how things go I might try it. JF
Use a dolly pot amd crush some quartz rocks, also you can crush some calcium alluminate brick and add that as well, i have not made one but the science adda up adding sillica and aluminate. I will try it since here a crucible is ridiculously hard to find or buy as an individual.
Looking forward to learn from your experience.
I am just about to make a ceramic holder for heating element with alumina and aluminium phosphate. They always started to disintegrate after some time...
fiber work as rebar in adobe. fiber is burnt down when bricks are cooked, making them lighter
Very interested about this whole process to reach metal
Yooooo, I figured out putting sand in clay to make it stiffer when I was 4 lived in Georgia, just kept digging in the sandbox till I hit clay (hope it was clay)
i'm using clay and sand mixed with ashes to see if it'll work well at high temps. hopefully the crucible will turn out good...
Dude, let me know. I'll be experimenting with more soon. JF
I made the crucible and it is light and handled melting a piece of copper wire with my small butane torch. It's interesting that the thing kinda worked!
That is so f-ing bizarre. I literally did this EXACT experiment last week. I wanted to try making glass, and I had clay on hand.
Tried with hay additive, beach sand and straight clay. The straight clay seemed to work the best and I'm currently drying my crucible for next weekend.
The reason I'm using clay is because I wanted to try and microwave it while the glass was still molten (see Cody'slab video), and a steel or graphite crucible would be very bad in a microwave. Plus I wanted a glass cube, and I just moulded the crucible accordingly.
Why not make video?
@@mamupelu565 A lot of work, that I have no experience with, and a whole 0 people would ever see :)
@@whynotdean8966 I subbed, now at least I will see ; )
@@mamupelu565 Cute, but don't hold your breath friend ;)
Think you could try making one with charcoal mixed in? Carbon stays solid up to ridiculous temperatures.
Also, could you try different methods for decreasing the time it takes to dry, like using desiccants or heat and good air flow?
Carbon could replace the sand here, if it was in a form that couldn't get burned more, like ash. decreasing dry time is both possible but generally not recommended because the outside will dry at a much faster rate than the inside, which would lead to more and deeper 'checking' since the outside will shrink before the inside does.
@@Animallovingpermie ricehusk have high silica and carbon content, can you replace fibre with that?
True that without oxygen it can stay as it is, as is done with clay graphite crucibles. However this is also how expanded clay is made so unless you really know what you are doing, stay away from organics.
Have you found out how high you can fire this clay before it melts? If you're using a DIY kiln, do you have temperature cones to judge how hot it gets?
Also, are you sure you want to glaze it? It seems like you'd be introducing an unnecessary variable into your melt. If you want a smooth surface couldn't you just dip it in a slip made from your clay body or burnish it?
I'll probably use a metal bar as a thermometer (color/temperature). I've heard that a glaze can be important, particularly when casting precious metals, since the pottery is porous and will absorb metal. As to how well this clay fires, well, that's what I'm here to find out. JF
Cool. Thanks man
random question, is it possible for roman concrete to be turned into a crucible?
No just clay and grog
Are stone crucibles better for metals.
Generally no. There's a lot of different kinds of stone, and the properties matter for this application. Most natural stone contains moisture, which can cause steam explosions and cause the crucible to break. Limestone breaks down in heat to become quick lime. Soapstone has decent enough properties, so it's been used traditionaly for making molds for bronze casting. But I'm not sure if it's been used for crucibles much. JB
To some extent it was but it has to be preheated and slowly brought up to temperature and they are prone to breaking, at least that's what I've heard. I make my own from clay.
The grass does not ad structural strength.
O
Theres red clay allover my yard
Makiking cruchible video
Please give me another video
Should add graphite
I'm a crucible theorist
Me too at this point.
Sand has no alumina, clay does though
Depends on the source rock and how much weathering the same has undergone. Also depends with Clay. Most of what we call Clay and sand is determined by particle size more than chemical makeup. JB
@GoodandBasic I understand what you are saying, but you are describing a clayey sand- or possibly a sandy soil, not sand on its own. Sand is just sand as in quartz grains under 2mm and over 2um in size. Its like saying glass has lead in it if you get it from a stain glass window... no it's glass.
It's important because sand intrinsically has no charge- which has impacts for agriculture. Alumina is part of aluminosilicate complexes which are the building blocks of what we call clay. This has a lot of charge and also can hold water.
And I'm so sorry you just happened to come across a soil scientist who was picking up on a minor point. I've spent a decade researching this, so it doesn't matter to most 😀
Google the soil texture triangle and you'll see all the available options. I hope we can still be friends!
Soil texture triangle sounds dirty.
@user-ug5sb6qg1u is the name of the best heavy metal band...
Actually give it a look. A unique feature of the dirty triangle (that sounds far worse, but also is a good name for a band) and you will discover its a3d projection in 2d. It's possible to add height to it, enabling you to comprehend.... 4D ON A 2D SPACE!
@@drfill9210 perversion and science, shaping up to be a good day. It's like watching Reanimator, but with more science.
My only question would be do you feel safe having something like this hold dangerous Molton metal surely there's a lot of risk involved
There's definitely some risk, some of which comes from making my own crucible and some of which just comes from the fact that it's casting molten metal regardless of the crucible type involved. I'll be extra careful as I figure out how good these crucibles are. JF
I searched for your follow-up video, but was unsuccessful. BTW, awful video regardless. You literally did something and then said "I hope it works." What a waste of time. 1/10
Yep he did lots of surface level research but didn't watch a single youtube vid on making crucibles. This is the kind of video a 7 year old makes. No experience, and no depth of research.