A wonderful guide to raku. I like that you admit when you're not sure about the answer to some question and seem so dedicated to the pursuance of knowledge and sharing it with others!
I don't know anything about raku but I do know that with primitive pottery that is fired very quickly on a wood surface fire, that 20% temper by volume to dry clay is a common starting point. Also sand that is more course (not weathered or worn down) gives the clay more to bite into. Washing out the tiny/dusty particles of sand will also make it more resilient to thermal shock. That is, get out the big stuff and the little stuff. Great video, thank you.
So I know this is an older vid at this point but I think I figured out the answer to your question. I believe what is happening is since you're using a clay that you usually fire at higher temperature at a slower rate by adding sand to it and rapidly firing it, causes a chain reaction, first since the quartz inversion point is much lower than the final temperature your heating it too the clay is still in a softer state when the sand rapidly expands and contracts leaving the clay porous and then due to the fact that the clay is now porous it increases the surface area of the clay making you able to fire it at a lower temperature than what is typically needed for the clay. Now this is just my speculation using knowledge I had stored, I didn't even look anything up just sat here for an hour thinking of how it works then trying to put into words. so I don't know if you'll ever see this but I hope you have a wonderful day.
Thank you for your videos, it inspired me to start experimenting with a raku kiln, at the moment I'm preparing a batch of terracotta and it has some sand and mika from the mine I digged out. :)
I've been adding silica sand and diamond tacious earth. This works well in my wild clay dug in Spokane. I have old brick and failed pots to grind up next.
I make beautiful Raku-fired pieces and I use Ontario-based PSH white grog clay #415 cone 06 which I Raku glaze fire to 1900F. Never cracks during the thermal shock.
If you're using a cone 10 porcelain, you could probably do raku with it without adding anything! Raku temps are so much lower, it won't expand/contract much. Try both and let me know how it goes!
Also going to try it 8n Atwood Fire kiln we just built and a put fire...so exciting...love nature and how these could react to porcelain...I can’t decide what clay body I like best! I love them all!
There's something soothing about your videos.
A wonderful guide to raku. I like that you admit when you're not sure about the answer to some question and seem so dedicated to the pursuance of knowledge and sharing it with others!
I don't know anything about raku but I do know that with primitive pottery that is fired very quickly on a wood surface fire, that 20% temper by volume to dry clay is a common starting point. Also sand that is more course (not weathered or worn down) gives the clay more to bite into. Washing out the tiny/dusty particles of sand will also make it more resilient to thermal shock. That is, get out the big stuff and the little stuff. Great video, thank you.
So excited to see a new video! Keep it up brother!!
So I know this is an older vid at this point but I think I figured out the answer to your question. I believe what is happening is since you're using a clay that you usually fire at higher temperature at a slower rate by adding sand to it and rapidly firing it, causes a chain reaction, first since the quartz inversion point is much lower than the final temperature your heating it too the clay is still in a softer state when the sand rapidly expands and contracts leaving the clay porous and then due to the fact that the clay is now porous it increases the surface area of the clay making you able to fire it at a lower temperature than what is typically needed for the clay. Now this is just my speculation using knowledge I had stored, I didn't even look anything up just sat here for an hour thinking of how it works then trying to put into words. so I don't know if you'll ever see this but I hope you have a wonderful day.
Just found your channel. Great work!
Thank you for your videos, it inspired me to start experimenting with a raku kiln, at the moment I'm preparing a batch of terracotta and it has some sand and mika from the mine I digged out. :)
That's awesome! I expect the mica will work great, please update me when you've tried it!
I've been adding silica sand and diamond tacious earth. This works well in my wild clay dug in Spokane. I have old brick and failed pots to grind up next.
I make beautiful Raku-fired pieces and I use Ontario-based PSH white grog clay #415 cone 06 which I Raku glaze fire to 1900F. Never cracks during the thermal shock.
Great video. Really appreciate the insight
Paperclay raku anyone? No buiscing, glazes applied to greenware, firing slowly first but from 150°C to 1040© in 3hours, taken out and doing the whole raku procedure .. i do these kind of firings with friends in oneday rituals and it amazes me how seldom cracks and complete breakdowns appear. But how exactly and why that works, i do not know .. but speeddry the greenware at a pizza temperatures in a oven first. Just to make shute the water evaporates properly. Cellulose fibres will burnband desintegrate at 350© so prepare for a certain smell. But this feels like old/new tech ... Anyone having similar experience?
I use regular stoneware clay with no problems in raku firing. In fact my stoneware clay has shown cracking in high fire use.
Thank you for this video.
What kind of wheel?
So is Raku pottery tempered against freezing and cracking?
Yes, it will withstand large and rapid temperature changes
I was told to add silica to porcelain if I wanted to use it for raku...which I do...so I’ll let you know how it goes!
If you're using a cone 10 porcelain, you could probably do raku with it without adding anything! Raku temps are so much lower, it won't expand/contract much. Try both and let me know how it goes!
@@tinkerandthink no, using laguna, a translucent cone 6 porcelain...but thanks for that info...and I will let you know how it goes! Love sharing info!
Also going to try it 8n Atwood Fire kiln we just built and a put fire...so exciting...love nature and how these could react to porcelain...I can’t decide what clay body I like best! I love them all!
Very cool 😎
Is your grog molochite?
Try rolling a slab that is not throughly mixed and see what you get.
I like
Can any body tell me where he has gone though *_*
Still here! I'll be posting more videos soon 🙏
@@tinkerandthink yeah buddy i'm hella excited ...... love your vids bro
@@tinkerandthink glimpse of light shine through when I saw your reply 😃
Hey, you seem to have disappeared, hope you’re okay.