Basic Slip Casting

[@erriiinnnng]

I'm doing some research for an internship so I've been watching a bunch of videos and this one is by far the best one I've seen. It's got all the elements an informational video like this one would need-- warm, educational, funny, and professional all at once. Thanks!

[@CaptMike]

Thanks for the kind words and thanks for watching my video!

[@michaelcaplan1589]

@@CaptMike I'm using it for my Materials Science class. They didn't understand slip casting of ceramics, so I found your video to explain it for them.

[@CaptMike]

@@michaelcaplan1589 If I can help in any way, please let me know.

[@thatjodiegirl72]

Agreed!

[@thecakeladytm]

Thank you so much for this video! Your voice is so pleasant to listen to and you sound so kind and reassuring. I have a buncha, buncha molds that I acquired super cheaply a couple years ago and never knew how easy it could be to get started using them. I'm going to go clean out a pottery room & get set up!

[@CaptMike]

Good luck with your slip casting. Let us know if you have question.

[@tarrahrobillard3300]

Capt. Mike- You are the nicest and best teacher ever

[@user-yk1hn2zx2b]

Great video! Thanks so much for sharing this information. You are so kind and generous. Wonderful!

[@CaptMike]

hank you for watching!

[@maggieann6437]

I've been taking my first cermics class and this has been really helpful, thanks so much!

[@bionicbulbasaur]

Thank you I'm doing research for a Christmas gift and this was super helpful

[@pontiacmoon]

Thank You

[@CaptMike]

Thank you for watching!

[@OUTSIDEMOORE_ANDMOORE]

Excellent breakdown Thank you

[@lukeprocopio3584]

The Bob Ross of clay.

[@baileybarnett2276]

Exactly what I was thinking!

[@mosseyw]

Thanks Captain , it was very informative 👍

[@CaptMike]

Thank you for watching my videos!

[@lorisvikel9504]

Love your video. What happens if you don't fire them because you don't have a kiln?

[@CaptMike]

Lori, you cast clay slip in a plaster mold. If you do not fire the clay it will remain soluable in water and if the piece gets wet or bumped (it's fragle) it will fall apart.

[@lorisvikel9504]

@@CaptMike Thanks!

[@claycool9435]

This is so cool.

[@CaptMike]

Thanks for watching!

[@matildasarrquinn]

Mike thank you so much for the tutorials. They are fun and easy for a novice like me to follow. I’ve just made a mould and put an unglazed pot into it, which is now stuck (as the plaster hardens). Happy to break the pot I want to replicate but my second problem is that I’m concerned about getting the slip out of the mould because the opening is small. What should I do? Haven’t started with the slip yet;)

[@CaptMike]

I the pot you are using as a mold is enclosed all around except for a small opening around the top, you will have to make a two part mold. If the pot is shaped like a flower pot, then when the plaster is dry (assuming the clay pot comes out) you will be in business as the clay slip will shrink as it dries and the molded pot will pop right out.

[@beatrizgrajales4181]

Capt. Mike, with the pandemic I had decided to try something new. I purchase a lot of plaster molds, wanted to start by using plaster París instead of slip clay, but it get stuck in the molds, can I work with plaster París or pottery plaster and do casting in the molds or I only can use clay slip on the ceramic/plaster molds. I am new and learning by reading and watching youtube. I enjoy yours. Please help

[@CaptMike]

The plaster molds are designed for clay slip. If you pour plaster into the you will not be able to get it out. A two part mold will stick completely together. If you cannot get clay slip, you can make it from moist clay. I have two videos on how to do this kzbin.info/www/bejne/gn-bqGB6fqqEgs0 and kzbin.info/www/bejne/pmTYiqmrbLafgMk

[@beatrizgrajales4181]

@@CaptMike thank you for the videos, it would be great if I can create a silicone mold using the plaster molds I already have. learning step by step thank you again.

[@CaptMike]

@@beatrizgrajales4181 I thank YOU for watching my videos. I wish you all the luck in your adventures. Glad to help where I can.

[@mariajohnston2147]

Thank you so much. This is totally new to me. It peaked my interest because I have a microwave kiln and while I make a lot of jewelry with stained glass I wanted to get more use out of the kiln and try something new. Can you please share where you got the slip and also the fiber to fix the kiln base. Thanks again

[@CaptMike]

No problem Maria. Tomorrow I will get to work on obtaining that info for you.

[@CaptMike]

Maria, you can start at Amazon for the Kiln fiber paper/blankets/liner, It comes in all thicknesses and lengths. As far as the slip goes, it depends on where you live as to how difficult it will be to obtain. I live in a small town in Georgia and I have to drive to Columbus, GA to get mine. It can be purchase on line, but the shipping might be a killer. Start here www.bigceramicstore.com/clays/clays-by-type/slip.html and do some research. As you will discover, it can also be purchased dry and you can mix it as you like. If you have other questions, please ask.

[@49lucky]

Well I'm a newbie now also great video.

[@FJR-ie7dk]

Good job It’s possible to tell us the interests for this liquid in details

[@CaptMike]

If you are refering to the clay, you can get commercial slip (liquid clay) or make it by liquifying a clay body and pouring it into a plaster moild.

[@shitheadjohnson2797]

be careful Mike! a mistake can be your last one!!! best wishes!

[@DellieTheBean]

Did you pour it out of the 3d mold as well?

[@CaptMike]

You only need to do one pour into a plaster mold. Pour in the slip. let it set for awhile (usually 30 60 mnutes) and pour out the excess slip. I usually let my molds set overnight, but at least until the clay is solid enough to be handled.

[@DellieTheBean]

Thank you :)

[@roybartels9827]

Great videos. Did you every make the one showing how you made the slip container?

[@CaptMike]

Roy, I have made only one video on how I make a simple plaster bowl mold for slip casting. There will be a video on two piece molds later.

[@aliciaowens7887]

Hi Capt Mike! I wonder if you are local to me! I just drive to Mackie’s last week and Val loaded us up! We are new to this..trying to start a church ministry. We just poured our first molds after watching this video. It is VERY hot in our metal barn. When we went to drain, some molds did not want to drain anything. Did we leave too long? We left the small ones about 20 minutes and large vintage mold about 35 minutes. We have had tons of rain but the heat was drying the slip quickly! Thanks

[@CaptMike]

I live in Elberton, GA. My shop is airconditioned so the high temps could play a big role. In a large mold I can leave the slip in for about an hour. Again, that depends on atmospheric conditions and how dry the mold is. What are the molds casting?

[@lauradavenport1645]

Do you need to do anything to prepare your molds before casting? Like put corn starch on them?

[@CaptMike]

I don't. I just make sure thay are dry enough. Maybe some one else here has an idea if something like that would help.

[@coleenhall7032]

Thank you so much for this!

[@CaptMike]

Thank YOU for watching!

[@HeatherWrightArt]

If you want a thicker walled bowl, can you let the first pouring of slip dry and then pour another layer before demolding? What did you do with all that leftover slip you poured out of the mold? I love your videos!

[@CaptMike]

Never tried a double pour. Usually I just let the slip sit longer in the mold. After the slip is ready to decant I just pour it back into the slip container.

[@HeatherWrightArt]

@@CaptMike ok, great, thank you!

[@ridgoro]

great video! thanks!

[@shaunimcgarva329]

wondering if you can do this with air dry clay slip

[@CaptMike]

Don't know anything about air dry clay slip, but if you can get it liquid enough it might work. What I would suggest is to first put some of the slip on the outside of the mold or on some plaster and see if it will release when dry.

[@pamelatyer1030]

How long do you wait before pour out of the squirrel

[@ArtesianDistillers]

Great detailed explanation . Thank you. What is the gray liquid material you pour into the plaster. Do you have video to show that also?

[@CaptMike]

The grey liquid is liquefied clay called slip. It can be bought commercially or you can make it by basically adding water to your clay body. When you pour it into the plaster mold, the mold adsorbs the water from the "slip" and solidifies it back into the clay body. The result is a cast of the inside of the plaster mold.

[@mikekiske]

@@CaptMike Is this clay food safe? Thank you.

[@CaptMike]

@@mikekiske The clay is food safe when bisque fired and the glaze will be depending on the type. All glazes will state whether they are food safe or not. Most are.

[@mikekiske]

@@CaptMike Thank you!

[@mrs.conscious]

Hello Capt. Mike EXCELLENT videos. I've been binge watching and learning. Thank you sir. Quick question I only have silicone mold that are food grade and can be heated so they are super durable. Can I use this for my clay slip? because I do not have plaster mold. My molds are only silicone grade. Or maybe I can use paris of plaster to pour into the silicone mold to make is plaster then use it with clay slip.. What do u suggest?

[@CaptMike]

The only problem with pouring slip into a silicon mold is the lack of absorption. That's what the plaster of Paris does. It absorbs the water from the slip leaving a clay shell. You clan press normal ceramic clay into the silicon mold and it will dry faster. You have nothing to lose by trying the slip. It will just take awhile to dry. Another idea (I am working on this as we communicate) is to make a master (positive) by pressing regular modeling clay into the silicon mold and then sticking it to the bottom of a container and then pouring plaster of Paris over that to form a mold.

[@mrs.conscious]

@@CaptMike hmmm I would love to see a video on your new idea you're cooking up and thx you. I'm not interested in making a clay shell. I want a full clay mold. Im making soap dishes btw. So either I can use modeling clay in the silicone mold or the slip.

[@samk8076]

You have such nice molds, how do you make them?

[@helpforhedgepigs8461]

Hi Capt Mike. I've watched loads of your glass fusing videos, and I'm intrigued to know if these types of castings once bisque fired, could also be used for glass casting? I've had limited success using clay for casting glass, and these look much more like the moulds I've had from Creative Paradise and Slumpys and it would be great to known if this is something I could use them for.

[@CaptMike]

Any clay item, bisque fired will work for slumping or forming glass. Well, at lest as far as the design permits. The bisque piece, once coated with glass release agent will stand the temps for glass work OK.

[@helpforhedgepigs8461]

@@CaptMike Thank you so much. I'm going to have a go at this. I think my clay pieces insulated the glass too much, but doing a thinner slip cast piece will allow more heat to get through the glass. Super excited. :-)

[@CaptMike]

@@helpforhedgepigs8461 Let me know how things turn out.

[@abigailmiller6983]

Hi! Excellent video. New to slip casting…how large do you recommend the length of the rubber bands relative to the circumference of the mold? I have a mold I just measured at 27”, so what size rubber band would you think I’d need for it to be tight enough, but not too tight? Thank you!!!

[@CaptMike]

Iuse 3 sizes, but off hand I don't know the lengths. However, Don't worry about the bands being too tight. Use the smallest you can get around the mold. thanks for watching!

[@tripslette]

Thank you, Capt Mike😂

[@nosvives7939]

Nice work Mike

[@RubyJuly24]

Nos Vives Thanks, Captain Mike! Very informative!.

[@miriamlipman6634]

Thanks for your videos, Capt Mike! After you initially pour the slip in, how long do you let the bowl molds sit in order for the sides to harden up?

[@CaptMike]

Depends om how dry the mold is and the weather. Usually, with fresh slip about an hour or until the slip looks to have formed about a 1/4 inch shell.

[@debbieclark5464]

I'm really new to doing ceramics. Can you tell me if you can make a plaster paris mold with a plaster paris object. So in other words I have a item that is made out of plaster paris and I want to make a mold of it in plaster plaster . Thank you I really enjoyed the video and have learned from it..

[@CaptMike]

If the final product is going to be a plaster duplicate of a plaster original, then I would make a mold from silicon or latex, depending on the subject. It is possible to coat a plaster master with enough stuff to keep it from sticking to the new plaster, but it is problematic. I have used cooking spray, Vaseline and Murphy;s oil soap to keep the second half of a two piece mold from sticking, but never tried to mold plaster to plaster. Unless the master is painted or something like that, I can assure you that plaster will stick to plaster. I will do a few experiments when I get a little time.

[@debbieclark5464]

I"m going to use the mold that I make with ceramic. I just need to make a mold from a object that is made already out of plaster paris. So i'm thinking that if i paint the object first with acrylic paint then use cooking oil , I"m thinking it will work ok...lol with fingers crossed. That will be great when you get free time to do some experiments ... Thank you for letting me pick your mind a bit...

[@catherinekuhle1859]

Do you know where the best place to order some slip mold I have one from a friend but I don’t know where they got it from

[@CaptMike]

You can start here: www.clay-king.com/slip-casting/slip-casting-molds.html or type "slip casting molds" in your browser and see where that takes you. Good luck.

[@shalomperez]

How long before you pour the excess slip out of the mold? how long was it before you pulled the acutual part out of the mold from the time you first poured the slit in?

[@CaptMike]

It depends n several factors, but mostly on how dry your mold is and the thickness of the slip. Under normal temperature 70-80 degrees F and average humidity my low fire slip obtains a desired thickness (shell) of about 3/16 to 1/4 inch in about 45 minutes; sometimes little longer. I live in Georgia USA. Demolding can be done as soon as the clay sip is ridged enough to be handled without deforming, usually 3 or 4 hours depending on the complexity of the molds. Slip can be left in simple molds overnight if you wish. Hope this helps.

[@markcaly342]

what do you do with the slip you discard? is it garbage or can it be re-used?

[@CaptMike]

I reuse it. Thanks for watching!

[@mygirlfriendismarcaline945]

So the water just needs to escape the clay right? Does this mean I can pour slip into silicon molds?

[@CaptMike]

Theoreticality you can, but the time it will take for the evaporation will be lengthy. Normally a plaster mold absorbs most of the water and speeds the drying.

[@alexandramascenon4052]

Did you use pottery plaster or plaster of paris for the mold?

[@CaptMike]

I used industrial plaster. I pay about $9 for a 50 pound bag.

[@MarchosArcade]

Hi Capt Mike , I'am new to this is it possible to pour molten aluminum in these plaster molds or will they not last long

[@CaptMike]

I don't think the plaster would hold up. If yu try, make sure the plaster is completely dry and use a flat one piece mold, not a 2 piece where you pour the metal inside.

[@vanimedeot7965]

💜Gracias.!🌹

[@hdb80]

So, this is how all those ceramic pieces are made that you go and paint and have glazed and fired at those art stores?

[@CaptMike]

Most of them that are ceramic bisque (fired clay). You can color them with ceramic glaze or use various paints to color them.

[@tmac20031]

How did you get the white finish?

[@CaptMike]

If you are refering to the molded piece, the "grey" slip turnes white after bisque firing to cone 06. The plaster to make the molds, of course, is white by nature.

[@jerrywhidby.]

Where will I find the rubber bands?

[@CaptMike]

Jerry, start here www.amazon.com/rubber-bands-molds/s?k=rubber+bands+for+molds

[@Metaldoodd]

How would you go about colouring a white or light coloured slip ? Would there be difference in dry time ?

[@CaptMike]

Here is a video I made on the subject. Hope it helps : kzbin.info/www/bejne/d2PIpnaQZqqGoq8

[@syafiqahmad1806]

Do you know what are the factors that affecting the casting rate/time?

[@CaptMike]

As best I can tell, water to plaster ratio, room temperature, and maybe the age of the plaster. I think I once read that using warm water would make the plaster set up faster and really cold water would make it set slower. Thanks for the idea. I will need to do a little experimentation.

[@syafiqahmad1806]

Thank you it is really helpful. Feel free to share your experimental results.

[@praveshpritvi3188]

Hello. Can someone tell the ingredients to mix in my clay for faster drying.

[@CaptMike]

As far as I know, there is no additive that will speed up the drying process without adversely effect the clay body (please jump in if some one knows differently). It should only take about three days, depending on your weather conditions for the clay to dry sufficiently to fire. Try a test piece in your kiln after 3 days and see if it holds up. A clue to whether the clay is dry enough is if it feels the dame temperature as the surrounding air when you hold it in your hands.

[@leroidesanimes]

olá! Fantástico seu trabalho. Poderia me passar a receita da barbotina? Obrigado!!!

[@rishabhmayank]

Can I use just clay solution as slip?

[@CaptMike]

Yes, I have put porcelain clay in a blender and added enough water to make it the right constancy. Don't add too much water as that will cause the mold to water log faster and your molding will not release properly.

[@rishabhmayank]

@@CaptMike Thanks a lot!

[@vishakhabhargava4070]

When I take my 2 piece mold apart, the piece is always brown in half. What am I doing wrong?

[@CaptMike]

By brown, do you mean inside the cavity? If I use my local clay for slip casting it always turns the inside of my mold brown/red. The casting will also be the same color. If you are using regular low fire clay slip purchased from a supply house, it usually will be grey in color and fire to white. Terracotta slip will be red. Let me know.

[@vishakhabhargava4070]

@@CaptMike sorry! That was a typo. What I meant to say is when I pull apart the piece, it's always broken in half. I measure the slip gravity everytime . I am starting to think it has to do with the mold itself. Do you ever find the slip being clogged in the mold? How do I make my molds better so they drain the slip properly?

[@CaptMike]

@@vishakhabhargava4070 after you pour the slip out of the mold, how thick is the walls of the cast? Do you wait long enough for the cast to set up. If the clay is too soft it will come apart when you demold. Better to wait until you are sure it is solid enough. If you are using a small mold,the slip might clog, but should not with a larger mold. Mind telling me what you are trying to cast?

[@shidiskas]

what is this clay - cement or what?

[@CaptMike]

The material poured into the mold is called slip clay. It is a liquified form of a regular clay body like you throw in a potters wheel, only formulated to be porable.

[@jensonrandall1557]

How much would you sell a mold for ?

[@CaptMike]

These are commercially produced molds. I bought mine here www.allisonceramicsupply.com/, but they are sold elsewhere.

[@gdzeek]

do these molds ever need some kind of mold release? My roomate said they need some kind of release? or is that just when the plaster molds are first being made?

[@CaptMike]

No they do not need any type of mold release. As you mentioned, the only time I use a release agent is when I am making the plaster old. Most of the time if the master is glass or plastic a mold release will be necessary. After the mold is made and dry all you have to do is pour the clay slip into it. As the slip dries it shrinks and pulls away from the plaster so you can remove the cast piece.

[@serafinflorendo340]

Where and how I can them fired up or use a kelm? Can I go to craft shop and have done there?

[@CaptMike]

If the craft shop sells bisque ware they usually have a kiln. Ask if the do and if they do not, ask if they know of anyone who works in ceramics. Usually anyone who has a kiln will fire stuff for you.

[@dosesandmimoses]

I used to love buttermilk.

[@mohammedlieze5519]

didnt knew forest gump doing slip casting is all i wanted

[@MrDragonfly1234]

Thanks !!!

[@jordanaryslim6236]

You sound just like my friend,Capt Greig Palmer

[@matthewshin621]

Where did you buy the raccoon mold?

[@CaptMike]

Here is their FaceBook page. I don't know if they have a website. Go figure. facebook.com/Allison-Ceramic-Supply-1042812882433088/

[@PengiwuCentral]

Plaster of Paris?

[@CaptMike]

Plaster of paris or plaster is what is used for slip casting. The plaster absorbs the miosture from the slip leaving a "shell" that will be bisqued.

[@PengiwuCentral]

@@CaptMike thank you for your reply. I just started experimenting with making my own moulds and learning that there are many types of plaster on the market, some not suitable for mould making. Like the kind you use to patch a wall, for example. I used plaster of Paris to make a few moulds and they turned out fantastic but when I used slip in them they didn’t form a shell and it was as if the slip curdled. So perhaps I need to try a different slip. But also making sure I have the right mould in the first place.

[@AlexRodriguez-ij7fh]

"Get online look it up" where do you think your video is? How do you think we stumbled into it?

[@CaptMike]

I'm sorry, I don't understand what you are commenting on.

[@2015072]

this is great!

[@daniellemarie6445]

Love it captain! Always a pleasure...

[@thewonderforest]

You sound like bob ross 🤗

[@CaptMike]

Just wish I had his artistic ability.

[@automaton20]

I was just going to say "If Bob Ross did ceramics".

[@accuratealloys]

Putting a clock in the video is impossible I suppose. How long did you wait before the pour or releasing them?

[@CaptMike]

I should have addressed the time involved, but in my haste I sometimes forget stuff. I mix the plaster into the water until it has all mixed in, about 3 or four minutes. When there are no more lumps to be seen I bump the container a few times to dislodge air bubbles and then slowly pour into the mold. Depending on several factors, temperature, humidity and plaster/water ratio, it should start to set up within 30 minutes....sometimes faster. Anytime after it has solidified it can be de-molded. Some directions say as little as 30 minutes. It can still be warm, but no water sitting on top. It is one of those things you will have to experiment with a little.

[@chalkychoochoo2304]

3:45 Doggo!

[@CaptMike]

Good eye! That's Toby.

[@chalkychoochoo2304]

@@CaptMike Toby is a cutie! Hey thanks for the extremely informative videos, been learning a lot!

[@GypsyPaz]

Nice video. Just wish you were more specific on times. "A little while" has much more context while your having a cup of coffee than it ever could in a paused video.

[@CaptMike]

Thanks for the comment Gypsy. If you could be more specific (what time in the video) you are referring to and I will try to learn from that. I am new to this KZbin thing and am aware I make a lot of mistakes. However, I try to learn from my mistakes and produce an enjoyable and informative video. I will re-watch the video again and try to see where I make vague references. Thanks again for you input.

[@DaveTexas]

All of those shapes are 3-D, so I don’t understand why he’s calling only one of them 3-D. 2-D would be perfectly flat and smooth, with no distinguishing features other than its outline.

[@CaptMike]

Hi David, I did not re-watch the video, but I guess I was referring to one piece molds vs 2 or 3 piece molds. In my experience a completely flat molding, regardless of how thick is a 1 D mold. A 2 D mold is one where you get detail on the top and maybe a little on the sides and a 3 D mold is one that completely detailed all around. this make any sense?