the rate of shrinking of clay isn't linear, a bulk of it happens at the quartz inversion temperature. If you preheat your clay to that it should suffer less dunting perhaps? it would have to be put back in the kiln to cool off after being torched of course. think about how glass blowers work. Your glass is just slightly more refractory :) I suspect what is happening with the wet clay is the force of escaping water, both physical and mineral, is so great it takes the clay unvitrified and dusts it around your studio. I'd try it with bone dry. Also I'm not sure if you've seen the thread few years back on digital fire about making your own crucibles by throwing 90% zircopax / 10% veegum on a wheel but that sounds like something up your alley. Cheers
I'd be interested to see what it does to a pot that's been glazed but not fired. What kind of effects can you get from hitting the raw glaze. And how could you incorporate that into a design 🤔
My very limited (~10 hours) glassworking experience yields a few thoughts: 1. preheating the area around the main site might prevent cracking. Maybe preheating the whole piece. Kinda depends on piece shape. You could try putting a piece on the wheel to apply heat evenly around the whole circumference, SLOWLY (over like 60-180 seconds, maybe) bringing the torch in from far away to let it heat up. 2. As another comment says, use more oxygen. 3. Glassworkers have special glasses that filter out "sodium flare", the bright yellow fire you get when applying flame to glass; might help you see what's going on, depending on how the other ingredients react to fire. Two thoughts on why the first test turned to dust. 1. Maybe the dried clay just got blown off by the air pressure? 2. I hear that heating wet clay causes water to boil off faster than it can escape, causing cracking. Maybe it was happening so fast that clay flakes just exploded off. Slow heating could again help either of those, maybe.
Very unique. I wonder if you could get a more broad effect with a rose bud tip. Also maybe pull a pot from a kiln while red hot like in a raku firing and use the torch on it then. That way the surface wouldn't be as shocked by the torch and prone to exploding.
The glassy look just reminds me of embedding pieces of glass into the outside of a pot. That would be a better way of achieving that look without the risk of breakage.
A few decades ago, a person was reheating ceramic materials with aluminum dust or even a solid piece of aluminum. The ceramic would absorb the aluminum and become stronger, and also had a musical quality! What you are doing tho, is turning the clay into glass, but like glass, it needs a few more ingredients to form better, like soda ash. Keep experimenting!
The sand dissipates the heat. So use it as a way to dissipate the heat I'm a item you want to use. Then let it cool and try and avoid any more thermal shock.
How about pulling pots from a Raku kiln, then augmenting them with the torch, then anneal in sawdust or whatever? Great experiment, i've always wanted to try this. Now I don't have to!
Amazing heat protection properties especially with the sand acting as a heat dissapator in the last one ❤amazing.i wonder if you put a laser temp gun on it while heating what the actual Temps where live time I'm curious now 😂 beautiful video very helpful!!!
To melt it without cracking I think you would almost need to do the melting inside the furnace. The ceramic would need to be very hot throughout, and it would need to cool slowly and evenly.
Not a scientist. Would say that as there was so much moisture in the clay, you essentially boiled the clay. The steam created then pushed the clay away, which is what caused the dust. With that you might has left over clay ranging from raw to vitrified in places. Most likely the hot steam would have ex-pulsed anything before you could really vitrify, but again not a scientist. As your second experiment shows with no water you were able to melt. Could be cool to use the carbon scarring for a sgraffito effect....
Not going to work. Ceramic is very heat resistant...i think you would need to go bigger. I say liquid oxygen, lots of pressure, stainless steel nozzle. Don't stand too close xD
It's quite a unique effect. Perhaps pre-heating the pieces in the kiln could help reduce the thermal shock/cracking issue.
the rate of shrinking of clay isn't linear, a bulk of it happens at the quartz inversion temperature. If you preheat your clay to that it should suffer less dunting perhaps? it would have to be put back in the kiln to cool off after being torched of course. think about how glass blowers work. Your glass is just slightly more refractory :)
I suspect what is happening with the wet clay is the force of escaping water, both physical and mineral, is so great it takes the clay unvitrified and dusts it around your studio. I'd try it with bone dry. Also I'm not sure if you've seen the thread few years back on digital fire about making your own crucibles by throwing 90% zircopax / 10% veegum on a wheel but that sounds like something up your alley. Cheers
I'd be interested to see what it does to a pot that's been glazed but not fired. What kind of effects can you get from hitting the raw glaze. And how could you incorporate that into a design 🤔
My very limited (~10 hours) glassworking experience yields a few thoughts: 1. preheating the area around the main site might prevent cracking. Maybe preheating the whole piece. Kinda depends on piece shape. You could try putting a piece on the wheel to apply heat evenly around the whole circumference, SLOWLY (over like 60-180 seconds, maybe) bringing the torch in from far away to let it heat up. 2. As another comment says, use more oxygen. 3. Glassworkers have special glasses that filter out "sodium flare", the bright yellow fire you get when applying flame to glass; might help you see what's going on, depending on how the other ingredients react to fire.
Two thoughts on why the first test turned to dust. 1. Maybe the dried clay just got blown off by the air pressure? 2. I hear that heating wet clay causes water to boil off faster than it can escape, causing cracking. Maybe it was happening so fast that clay flakes just exploded off.
Slow heating could again help either of those, maybe.
Very unique. I wonder if you could get a more broad effect with a rose bud tip. Also maybe pull a pot from a kiln while red hot like in a raku firing and use the torch on it then. That way the surface wouldn't be as shocked by the torch and prone to exploding.
What about doing it when it’s still hot from the kiln? The temperature may distribute better and maybe no cracks ?
The glassy look just reminds me of embedding pieces of glass into the outside of a pot.
That would be a better way of achieving that look without the risk of breakage.
A few decades ago, a person was reheating ceramic materials with aluminum dust or even a solid piece of aluminum. The ceramic would absorb the aluminum and become stronger, and also had a musical quality!
What you are doing tho, is turning the clay into glass, but like glass, it needs a few more ingredients to form better, like soda ash. Keep experimenting!
The sand dissipates the heat. So use it as a way to dissipate the heat I'm a item you want to use. Then let it cool and try and avoid any more thermal shock.
How about pulling pots from a Raku kiln, then augmenting them with the torch, then anneal in sawdust or whatever? Great experiment, i've always wanted to try this. Now I don't have to!
Amazing heat protection properties especially with the sand acting as a heat dissapator in the last one ❤amazing.i wonder if you put a laser temp gun on it while heating what the actual Temps where live time I'm curious now 😂 beautiful video very helpful!!!
Idea. Maybe preheating the ceramic before casting.
To melt it without cracking I think you would almost need to do the melting inside the furnace. The ceramic would need to be very hot throughout, and it would need to cool slowly and evenly.
It's mini explosions on the surface spraying off.
Really cool video.... just be carful the silica is volatile at theses temperatures and can a major risk to you.
The smoke effect is really cool. I wonder if you could preserve it?👏🏻
Your flame isn’t right. It should be blue . Too much acetylene not enough oxygen!
You're totally right. My glove kept bumping down the oxygen knob. Way to yellow and sooty flame. :)
This is a little off topic, but has anyone melted metal, say 925 silver onto a glazed (cone 10 porcelain) pot? I don’t want to compromise the pot
Not a scientist. Would say that as there was so much moisture in the clay, you essentially boiled the clay. The steam created then pushed the clay away, which is what caused the dust. With that you might has left over clay ranging from raw to vitrified in places. Most likely the hot steam would have ex-pulsed anything before you could really vitrify, but again not a scientist. As your second experiment shows with no water you were able to melt. Could be cool to use the carbon scarring for a sgraffito effect....
Try melting the test pots together
Do you have to apply so much direct close up heat? How about trying to stay back and using the end of where the heat is shooting out?
What did you think would happen with a torch that can weld and melt metal together? Think the ceramic is stronger?
Not going to work. Ceramic is very heat resistant...i think you would need to go bigger. I say liquid oxygen, lots of pressure, stainless steel nozzle. Don't stand too close xD