This is explained and demonstrated so well ❤ watched all your glaze chemistry videos and bought your books. I’m systematically trying each of your cone 6 crystalline glazes. Such a wealth of information 🤗
A simple tip so you know if you have added the right amount of defloculant. When you finish mixing the slip wait and watch it move in the bucket. When it stops moving keep an eye on a fixed spot usually a bubble. If when after it stops moving it moves back slightly in the other direction that tells you it's ok. This comes from over 30 years of mixing slip.
Eight years after you commented, but hey, why not? You’re saying that, if you have the right amount of additive, a deflocculated slip will stop stirring sort of like a car stopping a little rough, with a subtle jerk backwards? I’ll see if I can notice that! Interesting! Thank you. :)
Yes, because less water means less shrinkage. In industry they use deflocculated casting slip to put on handles - without- scoring. Tom Coleman used a cone 6 slip (thickened) as his joining slip because more flux help the joint better (as well as less water).
Great Video, John! I love your teaching style. You are so easy to understand. I have your glaze chemistry video and both the high fire and medium fire glaze recipe books, and have followed along with all your great videos for a long time. I always learn so much from you! THANK YOU for sharing all your knowledge! Keep being awesome!
Oh my goodness! Thank you so much for this. I made 50 mugs out porcelain and the join cracked in every one. I dried very slowly and attached pre pulled and dried handles and still got fissures. No breaks but lots of fissures. I am hoping that I will be good to go now.
I've been playing with slip decoration and had tried putting a little sodium silicate in, only to find it made my slip entirely too 'wet'. I'll have to try adding some more clay in, or epson salt water. Thank you so much for the video!
God, I've tried this many times, with many types of clay and I just can't get it to be magically liquid? Can you help me and explain what am I doing wrong? I was sick of buying expensive slip by the gallon online because there's no ceramic/pottery supply store in my town and with the shipping it's an absurd amount of money, almost $40.00 for 1 gallon of slip. In my previous town I would pay from $10 -$15 a gallon. I don't do this for living. I was always fascinated by clay and it's magic of creation. I bought 50lbs clay powder mix, half a pint of Darvan from Laguna company and couldn't wait to try making my own casting slip (I also have bout 10 plaster molds)..... I've also experimented with sodium silicate in the past with no luck as well. The slip turned out thicker than it was when I added the sodium silicate, a complete mess. I can not believe all the money I've spent and still can not make this work. I watch people's videos making it so easily without measuring or anything. I refuse to spend more money to buy and learn how to use one of those fluidity measuring tools. Ok, this is what I did: poured some lukewarm water in 5 gallon bucket (about 1 gallon), with about a table spoon of DARVAN and mixed it adding a little clay at a time until it was the fluidity I thought was about right (I mixed it for about 15 min.) Than I got one of my small molds and tested a little be to see how it would turn out. 5 min later the slip started shrinking and cracking so I added a little more DARVAN and clay as I mixed just in case the problem was too much water. Tried again and cracked. I was going to throw that batch away but I thought to myself, why not try 2 drops of sodium silicate. Tried, and didn't work. At one point I thought it was the mixer not being powerful enough to mix the slip well so I made my husband buy me an expensive DEWALT drill and a mixer attachment that coated over $100....This time, I did the exact same procedure of warm water and DARVAN first than add clay as I mixed with the exception of adding more water. So I kept mixing it and testing it on my molds and nothing. I've used most of the 50lbs dry clay mix and almost the entire DARVAN jar and the slip never worked nor it became super fluid like in this video. The thinner I could achieve was a semi thick pancake batter consistency/fluidity. Can you please help me understand why my slips don't work? I envy you and all the people that can make it with ease. Thank you!
PS. I own your Book! And I love it! At first I bought it because of the beautiful vase on the cover by Scote Cameron than I felt in love with all the info on so many additives and ingredients that I had no idea how to use. I hate that when I took pottery classes all we used was already industrialized stuff like glazes, over glazes, moist clays.......i'm too intimidated to try it, there are so many additives and chemicals and the way I'm OCD I would spend all my husband's money in order to experiment and try everything. So for the time being, I'm sticking to stupid pre made supplies (except the slip.... lol.....I won't rest 'till I get it right). But I love to know that your book is there whenever I decide to let go my fears and embark on the journey! thank you!
Thanks so much for this information, im in South Africa and i work with earthenware slip, can i use this same method to flocculate and deffloculate my casting slip? i dig moulds out of amp sand then i cast with slip inside, im on my way to develop a slip body durable enough for the brittle sand mould, you input will help.
John this was great, people have told me the process before, but I could not relate until I saw your demonstration. I am going to make a batch of slip for my porcelain mug handle attachments, and possibly some slip trailing. Does the same process work with stoneware slip making for handle attachment slip? Looking forward to the next video.
After using the Darvan, 811, my slip is gorgeous! Thank you! Do you then add more Epson salt solution back into your finished batch of thick slip to make it even more “fluffy”? Thank you, John, I have learned so much!
Great information! Thank you so much! I'm wondering about bacteria growth and mold within finished product. Is bacteria or mold an issue? How do you prevent it? I could make a smaller batch, eh? However, I would like to make a big batch to have on hand when needed.
Bacteria and mold are just a sign of aging. If you are reprocessing your clay, this can be good thing because they improve the workability of the clay. But they do this by increasing flocculation, so you might need to add more Darvan to keep the slip deflocculated (although tbh i have never had to do that). And, unless you have a mold/mildew allergy, I don't believe there are any health effects. Hth.
That is so fascinating John. If you are sliptrailng with the thinned more watery slip will it stay raised since the clay content is so high. When Angi uses a thick slip to trail with she gets lots of air trapped in the slip.
When I mix it up and it becomes fluid again "thixatropic?" it wants to flow and flatten right out on the surface of my pots. How can I keep that from happening? I want to keep it thick and standing up. Obviously i am by nature moving/mixing it when I apply and use it. Thanks
Hello. I just would like to make some regular slipware, and try to understand what to do with regulas slip (water and cly), to make a slip that does not crack on the pots after applying and drying or firing. Can someone please help!?
Not sure what you are asking..Regular Slip is not a term....Slip from your throwing bucket is very high in clay and clay dries and shrinks. You may want a Slip Recipe with low clay so less shrinkage?
Hi John. Love to watch your videos. You make it so easy to understand. I am trying to deflocculate some slip which is made from my clay body trimming (porcelain) to use in screenprinting. I am only trying in a very small amount. When I added Sodium Silicate, it thickened instantly, instead of thinning. I am not sure why. Can you share some light? Also, what would you suggest % of sodium silicate add to slip to use in screenprinting?
so when you add the darvan 811, you make the slip "thin" but it will be a trailing slip? more clay per water molecule? or do you just make a super think slip, 2 parts clay to 1 part water, and then add the darvan? i know, clear as mud. for sgraffito you would use a thin but unshrinking slip?
Peter, he is using an immersible blender stick, like you would mix smoothies or mixed drinks in the kitchen. A lot of potters that I know (including myself) like to keep one of these dedicated to clay use handy for things like this and mixing clay. You can usually pick up one from the kitchen section of any department stores for fairly cheap.
It's an immersion blender he is using to mix the slip. Cooks use them, so try a kitchen supply store. They are usually smaller than that one. You can also use a paint mixer attachment from your local home improvement store, affixed to a hand drill.
Add a bit of chlorix bleach to kill bacteria, but it is really unnecessary. In a white body it will make it black or grey, but go back to white as it dries.
This is the go to guy for answers. Always a big help.
great video! I can tell you are a scientist but you keep it simple for the rest of us! Thanks John
This is explained and demonstrated so well ❤ watched all your glaze chemistry videos and bought your books. I’m systematically trying each of your cone 6 crystalline glazes. Such a wealth of information 🤗
A simple tip so you know if you have added the right amount of defloculant. When you finish mixing the slip wait and watch it move in the bucket. When it stops moving keep an eye on a fixed spot usually a bubble. If when after it stops moving it moves back slightly in the other direction that tells you it's ok. This comes from over 30 years of mixing slip.
Eight years after you commented, but hey, why not?
You’re saying that, if you have the right amount of additive, a deflocculated slip will stop stirring sort of like a car stopping a little rough, with a subtle jerk backwards? I’ll see if I can notice that! Interesting! Thank you. :)
Yes, because less water means less shrinkage. In industry they use deflocculated casting slip to put on handles - without- scoring. Tom Coleman used a cone 6 slip (thickened) as his joining slip because more flux help the joint better (as well as less water).
Always enjoy your mini classes!
Great Video, John! I love your teaching style. You are so easy to understand. I have your glaze chemistry video and both the high fire and medium fire glaze recipe books, and have followed along with all your great videos for a long time. I always learn so much from you! THANK YOU for sharing all your knowledge! Keep being awesome!
John- You make the best videos :) This is something I really needed to know, so I appreciate it so much!!!
Great demonstration of an interesting technique. Thanks.
Dude. This video just blew my mind.
learningsomething new while drinking my morning tea a good start to the day thanks john.
Awesome explanation, John. Thanks once again!
Wow, that was fascinating!
Worked very well! I used sodium carbonate (washing soda).
Oh my goodness! Thank you so much for this. I made 50 mugs out porcelain and the join cracked in every one. I dried very slowly and attached pre pulled and dried handles and still got fissures. No breaks but lots of fissures. I am hoping that I will be good to go now.
I've been playing with slip decoration and had tried putting a little sodium silicate in, only to find it made my slip entirely too 'wet'. I'll have to try adding some more clay in, or epson salt water. Thank you so much for the video!
Great information! Thank you so much
Nice Bruce....thanks.
Actually quite amazing !
God, I've tried this many times, with many types of clay and I just can't get it to be magically liquid? Can you help me and explain what am I doing wrong? I was sick of buying expensive slip by the gallon online because there's no ceramic/pottery supply store in my town and with the shipping it's an absurd amount of money, almost $40.00 for 1 gallon of slip. In my previous town I would pay from $10 -$15 a gallon. I don't do this for living. I was always fascinated by clay and it's magic of creation. I bought 50lbs clay powder mix, half a pint of Darvan from Laguna company and couldn't wait to try making my own casting slip (I also have bout 10 plaster molds)..... I've also experimented with sodium silicate in the past with no luck as well. The slip turned out thicker than it was when I added the sodium silicate, a complete mess. I can not believe all the money I've spent and still can not make this work. I watch people's videos making it so easily without measuring or anything. I refuse to spend more money to buy and learn how to use one of those fluidity measuring tools. Ok, this is what I did: poured some lukewarm water in 5 gallon bucket (about 1 gallon), with about a table spoon of DARVAN and mixed it adding a little clay at a time until it was the fluidity I thought was about right (I mixed it for about 15 min.) Than I got one of my small molds and tested a little be to see how it would turn out. 5 min later the slip started shrinking and cracking so I added a little more DARVAN and clay as I mixed just in case the problem was too much water. Tried again and cracked. I was going to throw that batch away but I thought to myself, why not try 2 drops of sodium silicate. Tried, and didn't work. At one point I thought it was the mixer not being powerful enough to mix the slip well so I made my husband buy me an expensive DEWALT drill and a mixer attachment that coated over $100....This time, I did the exact same procedure of warm water and DARVAN first than add clay as I mixed with the exception of adding more water. So I kept mixing it and testing it on my molds and nothing. I've used most of the 50lbs dry clay mix and almost the entire DARVAN jar and the slip never worked nor it became super fluid like in this video. The thinner I could achieve was a semi thick pancake batter consistency/fluidity. Can you please help me understand why my slips don't work? I envy you and all the people that can make it with ease. Thank you!
PS. I own your Book! And I love it! At first I bought it because of the beautiful vase on the cover by Scote Cameron than I felt in love with all the info on so many additives and ingredients that I had no idea how to use. I hate that when I took pottery classes all we used was already industrialized stuff like glazes, over glazes, moist clays.......i'm too intimidated to try it, there are so many additives and chemicals and the way I'm OCD I would spend all my husband's money in order to experiment and try everything. So for the time being, I'm sticking to stupid pre made supplies (except the slip.... lol.....I won't rest 'till I get it right). But I love to know that your book is there whenever I decide to let go my fears and embark on the journey! thank you!
Thanks so much for this information, im in South Africa and i work with earthenware slip, can i use this same method to flocculate and deffloculate my casting slip? i dig moulds out of amp sand then i cast with slip inside, im on my way to develop a slip body durable enough for the brittle sand mould, you input will help.
John this was great, people have told me the process before, but I could not relate until I saw your demonstration. I am going to make a batch of slip for my porcelain mug handle attachments, and possibly some slip trailing.
Does the same process work with stoneware slip making for handle attachment slip?
Looking forward to the next video.
After using the Darvan, 811, my slip is gorgeous! Thank you! Do you then add more Epson salt solution back into your finished batch of thick slip to make it even more “fluffy”? Thank you, John, I have learned so much!
You deflocculate it, then add more clay - which thickens it.
And when you use that slip, it holds together twice as well, because of the added clay
Great information! Thank you so much! I'm wondering about bacteria growth and mold within finished product. Is bacteria or mold an issue? How do you prevent it? I could make a smaller batch, eh? However, I would like to make a big batch to have on hand when needed.
Bacteria and mold are just a sign of aging. If you are reprocessing your clay, this can be good thing because they improve the workability of the clay. But they do this by increasing flocculation, so you might need to add more Darvan to keep the slip deflocculated (although tbh i have never had to do that). And, unless you have a mold/mildew allergy, I don't believe there are any health effects. Hth.
That is so fascinating John. If you are sliptrailng with the thinned more watery slip will it stay raised since the clay content is so high. When Angi uses a thick slip to trail with she gets lots of air trapped in the slip.
Just let it sit a while and then tap the squirter bottle.
Very smart. Appreciated video.
What a great video, so informative for a newibe, THANKS
When I mix it up and it becomes fluid again "thixatropic?" it wants to flow and flatten right out on the surface of my pots. How can I keep that from happening? I want to keep it thick and standing up. Obviously i am by nature moving/mixing it when I apply and use it. Thanks
Will it still flow thru the slip trail bottles?
@@leahmallow9863 yes
Hello.
I just would like to make some regular slipware, and try to understand what to do with regulas slip (water and cly), to make a slip that does not crack on the pots after applying and drying or firing. Can someone please help!?
Not sure what you are asking..Regular Slip is not a term....Slip from your throwing bucket is very high in clay and clay dries and shrinks. You may want a Slip Recipe with low clay so less shrinkage?
Hi John. Love to watch your videos. You make it so easy to understand. I am trying to deflocculate some slip which is made from my clay body trimming (porcelain) to use in screenprinting. I am only trying in a very small amount. When I added Sodium Silicate, it thickened instantly, instead of thinning. I am not sure why. Can you share some light? Also, what would you suggest % of sodium silicate add to slip to use in screenprinting?
Sosan, watch his video again. He answers your question.
Is it possible to mold with slip? I'd like to make a sculpture but i only have a bucket of slip.
Not really
so when you add the darvan 811, you make the slip "thin" but it will be a trailing slip? more clay per water molecule? or do you just make a super think slip, 2 parts clay to 1 part water, and then add the darvan? i know, clear as mud. for sgraffito you would use a thin but unshrinking slip?
Yes, but stoneware slip has grog which can clog applicators so watch that.
If I make a thickened slip in the manner you describe, will it work better as joining slip, and why? Thanks much!
Please sir can you telling me all material to make liquid clay
Hi John, is it sufficient to just use Sodium Silicate? Or is the soda ash necessary?
For what I am doing...sodium silicate is good....for slip casting you need both...
@@johnbrittpottery Ok, thanks!
Hello is it necessary to add sodium silicate and what is its role?
To deflocculate the slip
please make video on cte
hi I have a pail of ceramic slip that's way to thick I added silicate but it's not working or maybe I used to much😮
Not sure...try adding some water.
Hey John we tried this using Darvan 7 and it didn't make much of a difference at all. Not nearly as dramatic as 811. Is that normal?
The strength of 811 (and price) is different from 7. Hope this helps!
What is the name of that electric hand tool you are using? Pete
Immersion blender..walmart..
Peter, he is using an immersible blender stick, like you would mix smoothies or mixed drinks in the kitchen. A lot of potters that I know (including myself) like to keep one of these dedicated to clay use handy for things like this and mixing clay. You can usually pick up one from the kitchen section of any department stores for fairly cheap.
Thanks much!
crazy question.... What is the brand name of your handheld blender? My handheld keeps dying.
they all die..I consider them disposable so buy a new one every three months or so...walmart
I keep getting points on my slip trailed dots. How do I avoid that?
Sponge before bisque firing!
waaooo! what is the name of the thing that you used to mix the slip?
I think he said Darvan 811
It's an immersion blender he is using to mix the slip. Cooks use them, so try a kitchen supply store. They are usually smaller than that one. You can also use a paint mixer attachment from your local home improvement store, affixed to a hand drill.
clay how to do and what I should add and to get ?
Watch more videos on slip trailing. Add darvan by the tablespoon to the slip mix well. Or add sodium silicate.
good info. thanks
Add a bit of chlorix bleach to kill bacteria, but it is really unnecessary. In a white body it will make it black or grey, but go back to white as it dries.
yes, 811 is Very strong.
can you use this porcelain slip for slip trailing on stoneware
I dindnt know you can use water.
Sometimes it is just a bit short on water/fluid to make it work. Funny ratio and if not right it gets stiff.
I try anything
too much sodium silicate. ...only need TINY amount!
thank you!