Making a two piece plaster mold

[@SaSeshen]

Honestly, I love the fact you just went ahead and did this, with no BS commentary and just describing, quickly, but efficiently every step of the process. This is fantastic!

[@TheEstanton5]

I was just coming to comment this same thing I love how easy it was to understand

[@Brunomgonzalez]

I appreciate you showing me the down and dirty way John! This is going to help with my sculpting class. Thank you sir.

[@johnbrittpottery]

Nuts and bolts all day long.

[@julielorusso4410]

You do an excellent job explaining and getting to the point. This is the best most no nonsense technique I’ve seen. Thank you!,

[@joeygunzilla6878]

👏 THANK YOU! I just needed the basics of how this is done.. my project isn't anything critical. I remember a time when KZbin was this simple! Straight, to the point, solid info.. those were the good days ✌️😎🤙

[@bwolfwilloughby]

Awesome! Everything you needed prepared for quick shooting, your camera focused close in when needed, great quick technique (LOVE the flashing!), clear audio. Excellent tutorial! Thank you!

[@iwannatry2]

Great tutorial. Clear and straight to the point. I feel more confident about making plaster molds now. Thank you so much!

[@marcrosenthalstudio]

Love the use of the tin for the coddle. This is a lot simpler than dealing with belts or bands and it is locked into place with the clay. Thanks, John!

[@lynndomsicz6155]

love the vid. no fluff or filler. got right to the point . great

[@yosrael-saghir9256]

Fast, accurate, clean, thorough.. best video for casting

[@Engelhafen]

You are a great instructor - right to the point and clear

[@Dookiedolf]

Im new to mold making so I've been watching lots of videos to glean as much info as I can before starting. I've learnt 4 techniques from your video that I havent seen on others. Brilliant video packed solid with info. Thanks for taking the time to share your knowledge.

[@stadafradabrikenbraken9106]

I like the way you do your videos John ..you don't linger you just quickly go through the process and let us figure out the rest ..perfect

[@TDGCmote]

thank you! I have wanted to move from 2D art to 3D for a long time, and this is incredibly helpful!

[@johnbrittpottery]

Just did a 3 piece mold video.

[@wang-lingchou1023]

Thank you so much. Your method is so simple and easy, yet still have very good result. I introduce your videos to my students. The way you demonstrated fits our need and situation very well. I am deeply appreciate your videos.

[@123Christeena]

Such a wonderful video. Very clear and easy to understand. Thank you.

[@youdication]

@johnbrittpottery many thanks for sharing the info.my daughter had a school project ,and i kept searching the internet for ways to mold the seashells and there it is! i found your nice, informative, down to the point video.. thanks for taking the time to share it.

[@006guitarplayer]

This helped out tremendously. I plan on using this 2 piece plaster mold method to cast aluminum. Can't wait to try it out!

[@DZAROVNY]

That definitely took the mystery out of it, I'm now confident to go do one tomorrow while its hella raining outside. Thanks John!

[@mamabird231]

Down and dirty is good. Thanks for about 2 dozen new hints!!

[@DirtKickerPottery]

Made a little one today for beads. Turned out great! Thanks a million John :)

[@marc0871]

yes, it does. i worked with a professional moldmaker. he used a closed cilinder with a low speed blender and a vacuum pump to get the trapped air out of the plaster. but you could get the most of the big bubbles out by gently stirring it or tapping the bucket on the ground. break the bubbles by blowing on it or remove them with a spoon.

[@johnbrittpottery]

You have to wait for the clay to stiffen in the mold. I press them at 5:00 p.m. and then in the morning they are ready to take out.But if your plaster is too hard ( meaning non-absorbent) then you can use any release - like Murphy's Oil soap, Or if you aren't going to pour it EVER then you can use Vaseline but that will seal up the plaster and mess up the absorbency. (Which is why you use plaster - it absorbs the water from the clay and the clay then shrinks to release itself.)

[@Exiria]

WOW! Surfing the web figuring out how I'm going to DIY some festive candy moulds, it's all become so much simpler now. THANK YOU!

[@taradouglass336]

Finally a good video that explains how to make a mold. I looked at a lot before this.

[@klarenaugen]

this seriously saved me so much time by your little trick! thank you! I want to know more of your tricks

[@satsypox]

i have been looking for you for years..thanks for sharing your knowledge..

[@cheffjeffB]

Clear and to the point, very helpful. I am experimenting with ways to use recycled HDPE (plastic) and might try your technique to make molds I can press the hot gooey plastic in to form and cool. Plaster may not take sufficient heat and pressure to do the job but that is part of the experiment. Thanks.

[@bucu1988]

This is really a nice simple method. I like it.

[@2techshop]

Thanks, love your video. Great job, explaining the mold making process.

[@madogaso]

A great way "how to" make a plaster mold! thank you very much for your useful help!

[@johnbrittpottery]

You could cast with anything, but just drill hopes on both sides sides so the plaster can get in. You need to seal the mold and the holes so the new plaster doesn't stick in there. People who make plaster pieces prefer rubber molds.

[@alancastaneda8322]

Did you use cooking oil as a separator for the two gypsum pieces of your mold wouldn't stick to each other?

[@johnbrittpottery]

Yes

[@marc0871]

you could try to get a hold of a bar of sunlight soap, cut it up in a pan and heat it up in a bigger pan with water (au bain marie). mix it up with some vetageble oil and cook it for about an hour while regularly stirring. you can use the resulting substance as a releasing agent.

[@nealabornman294]

Greetings from South Africa - so pleased I have found your videos! Can you use this method for making a two piece mold for a dinner plate? I want to slip cast plates. Love your teaching style!

[@Cate7451]

Yes

[@Birshykat]

Hi John, First off, thanks so much for the great video! You made mold making seem less intimidating. I made the first half of my mold yesterday & planned to pour the second today or tomorrow. After thinking about it, I was wondering, do I have to wait for the first half to dry completely, before pouring the second half of the mold? If so, couldn't that take a week or two? I guess my question is how long should I wait before pouring second half of my mold? This mold is for a Christmas ornament that I plan on making for family and friends, so time is a factor. Any info would be appreciated.

[@johnbrittpottery]

Birshykat you just wait until it is hard...30 minutes. You will feel it get warm.

[@Birshykat]

Thank you, John. Made a mold for an annual Christmas ornament, that I make for family members. Had a few hiccups, but my mold turned out good enough for the purpose I needed it for. If interested, you can see pictures of my hair-raising process & completed ornament here! Your video was so helpful. Not sure what I would do without these type of videos. www.flickr.com/photos/43442753@N08/with/32198013816/

[@makdoes]

Thank you, this was my exact question too.

[@AllyCarts]

I tried to make a plaster mold but the plaster dried to fast for me to properly pour it in, should I just add more water or what?

[@sadville13]

You should probably restart and next time add the water first and only add plaster till it reaches the top of the water. If it's too runny you can shave plaster off into it and it will start setting quicker. Just play around until you learn how to use it in different ways.

[@jewel.Bug.Creations]

Thanks going to try in a few days for my wax warmers

[@illucy2]

John how do you make a mold you pour the slip in from the top? I'm just learning and I have something I want to make a mold for.

[@RyanReta97]

This is gonna help out a lot. Great video 👌👌👌

[@pseudoweapon]

Well done. Thanks for the video. What way would you suggest if I wanted to make a plaster mold of a walking stick that I have?

[@celesterobertson5238]

Thank you so much, I've been trying to find a vid this useful for days!

[@sarahmorgan574]

Do you think this would work to make a mold for slipcasting?

[@shannon165]

First, what kind of clay do you press your bones into? It doesn't harden? Second, great video, I can't wait to get started making a two piece mold of my own :) THanks!

[@sadville13]

This man knows how to get a job done! Down and dirty for sure.

[@brandonartificial]

@John Britt just curious, if you can make a two piece plaster mold and use it to form a plaster mold. That might sound a little confusing, basically... once your 2 piece plaster mold is made, can you pour plaster in it, (instead of the clay like you did) or will it just form a brick? I need a way of making a 2 piece mold so I can make plaster pots faster and with just 1 mold

[@Cate7451]

Seal it with mold release agent

[@DirtKickerPottery]

Thanks John. So when are you going to get around to writing a cone 6 glaze book?

[@beesinitaly2416]

What does he mean by cleaning the "undercuts" at 0:23 ?

[@peterchessell1949]

+Bees in Italy He showed you!!!

[@sadville13]

He means that there is a flat edge between the clay and the object you wish to make a mold from. If you have crevices and things the plaster will be so thin in those parts that it will break off.

[@kevindonohue2912]

Whatever you are making should come out of the mold easily, so the edge of the mold needs to follow the object's widest point. Think of a ball - if more than half the ball is in either piece of the mold, you won't be able to remove it.

[@RainOfTerrorFilms]

Simple Easy Down and dirty Thanks man you have Re assured my prop making possibilities

[@k.l.taylor6558]

Hello John, I need to make a mold of a bowl type structures that has some odd undercuts. Being that the shape is round would I need to make a 3 part mold with square outside corners so I can hold the mold together with a cinch belt? This mold will be used for Terracotta.

[@Mikemillering1]

Thanks for the video! It helped us create an awesome gnome!

[@emmin.556]

Hi John, Is that oil based clay or air-dry clay?

[@hossamslime9354]

Nice video I just asked What formula of dish melting of metal like gold

[@johnbrittpottery]

???

[@joedouglas3696]

Great. What's the purpose/reason for the small amounts of clay on the bones in the plaster cast at the end? Following the method, shouldn't it just be plaster on plaster?

[@johnbrittpottery]

Removing undercuts

[@chezsuzie]

Genius! SO easy! Thank you for sharing this! A couple of questions: you mention using soap as a release. What kind of soap and assuming you mix with water, the ratio of soap to water? Also, can I use Plaster of Paris?

[@Birshykat]

I have been told you should use pottery plaster for the best results when mold making. Last week, I purchased 25lbs. of K-60 pottery plaster for about $12. Look for a pottery supply store in your area. I went to my local pottery supply shop and explained my project to the clerk. He thought K-60 would work best for what I planned to make. First half of mold poured and this plaster has been really easy to work with. BUT...by no means am I an expert!

[@Cate7451]

Birshykat not an expert either but yes potters plaster is stronger than plaster of Paris so the latter won't last as long.

[@b4letta]

I am going to attempt to make a vase using your "Making a two piece mold" video. I will be using it to pour slip or wet clay so how do you make a pour gate?

[@draggersprez]

how would i go about making a mould of something that isn't totally 3d like a fin of a mermaid tail? would it work exactly the same? (i mean, would i cast or sculpt the fin first then push the hardened fin sculpt into clay like the chicken bones and cast from there?)

[@johnbrittpottery]

Try it and see. If you keep the blade from making a vortex it doesn't. Also check out professional plaster people and you will see they often use a blunger.The worst way to mix is with your hand!

[@Whiteboy199888]

Can u make a mold for soft plastic fishing lures?

[@nedman98]

Say I were going to put a ball bearing into a molding process, would this technique work for making a mould to be used repeatedly?

[@bigjallday1]

can u also, instead of pushing clay, just lay strips of paper in the mold to make the paper bones?

[@GauleyRiverPotteryMountLookout]

awesome! Love the flashing idea.

[@CecilyHeron]

Great video, it's surprisingly hard to find simple, easy to follow instructional videos on the internet! Regarding using soap as a release agent, do you mean mixing a bar of soap with water, or should I use liquid soap?

[@TheCreater51]

thank you for this video Im in Ap art at my school and tried doing a mold of a figurine but i never scraped the sides like you did. would cardboard work instead of the sheet metal? and also for a release agent all i have is WD 40 would that suffice or would something like non stick pan spray work better?

[@killerbeenl83]

I down and dirty put a lit on the mix with a hole and a small hole on the side. And put the vacuum cleaner on it for 5 minutes to get the air out. Works like a dime. Mix slowly every minute. And repeat.

[@Thatdude1281]

I tried this just a day ago with an old badge . I used just hardware store plaster of Paris . Most of the detail broke off into the existing piece when I separated it . Is plaster of Paris the wrong type ?? Did I maybe not let it dry long enough ( it was about 1-1/2 - 2-1/2inches thick ) and I let it dry for about 10-11 hours . Am I using the wrong type of plaster? Or being impatient

[@johnbrittpottery]

Did you vaseline the badge? Also fill undercuts? Try those ideas and then stronger plaster...#1 pottery plaster is what I used. Many types, hydrocal is hard but Not good for slip casting.

[@Thatdude1281]

John Britt I managed to get one that came out good . I didn’t use anything to lube the surface for the first one but used mineral oil lightly brushed on the mold for the second and it came out good . They’re just far too fragile . I may just use resin. But I had plaster on hand so used that haha . I didn’t know about pottery plaster ?? I wanted to try and slip cast a mug . But everything I’ve looked up to make slip needs old dried clay and a blender . Seems like a lot of extra work when there MUST be an already usable slip to cast a mug ? That also doesn’t have to be kiln fired ? I’m green as hell so sorry if this all sounds really stupid haha . I’m just bored and can’t tattoo so need to create something . And this was something I’ve always wanted to try and do . Thanks for the advice !!!!!

[@johnbrittpottery]

@@Thatdude1281 you can buy slip..Try AXNER Pottery supply...You need plaster because it absorbs water from slip .

[@Thatdude1281]

John Britt thank you ! I didn’t know I could buy slip . I will definitely look that up .

[@benwf007]

Hi, Great video, was very insightful! however I have a question, If instead of filling the mould with clay , would it be possible to cast the chicken bones out of plaster, as to get the final product made out of plaster. How would you go about creating venting holes to pour plaster into the mould? Or is there another approach? Thanks

[@shelliharsha]

Can you cast concrete in a plaster mold? I'm trying to find a more inexpensive way to mold concrete than using rubber. The piece will only be 3-6 inches.

[@lizzykorwan]

can you use this for making ceramic pot molds too i'm a potter and i just wanna ask that

[@munchegod]

Thanks, one more question, would it be better to make these moulds with a thinner mixture of plaster, I used much thicker stuff than you for my moulds. Thanks again.

[@centaurus777]

So is the bone chair made from plaster bones or is it made of hardened clay of some sort?

[@johnbrittpottery]

If there are undercuts the mold or model won't release.

[@johnbrittpottery]

They have Release Soap but you can use Murphy's Oil Soap.

[@johnbrittpottery]

Well the absorption of the plaster is a function of the ratio of water to plaster so if you add a lot of plaster it will absorb less water/be more dense. So the way I do it is by the chart. Google a plaster water ratio.

[@shawndoe2834]

Hello & Thanx for your video. Can you omit the clay & just use Plaster-Of-Paris (POP) for both sides? Example: Pour POP, wait till it firms up, then push your chicken bones 1/2 way into the POP, and wait till it hardens? Thanx For Your Time: 191,560 is a lot of views!!!

[@manuelluis5456]

... ????? you would have ONLY HALF of the coins / ( my bad sorry ) HALF OF THE BONES ... ( am l right ? )

[@kevindonohue2912]

In theory, yes - but plaster hardens from a chemical reaction that happens pretty quickly. If you press something in too soon, it might sink into the plaster, too late and the plaster will get too hard. If you can get the timing just right it should work, but starting with clay gives you more time and control.

[@whatshername3158]

i love guys' vids,straight and to the point.women babble endlessly,i can 't take it!cool!!i've always wanted to do this!great vid,thanx!!i subscribed!

[@saduck1]

Thanks I'll try this, thank you for taking the time to teach us!!

[@sorin990]

Can you put plaster and\or cement in the plaster mold ???

[@johnbrittpottery]

yes. jus seal mold first.

[@sorin990]

John Britt and by seal mold you mean adding demolding agent ? ....thanks for your info ^^ great video !

[@Cate7451]

sorin990 yes

[@MedleyUnlimited]

Thanks for this video. It gave me some ideas for new projects.

[@claybakin2478]

brilliant, thank you john!

[@tetherflex]

I'm looking to make a plate mold with a design on the rim. Would I need to make a 2 piece mold? And how would I pour slip in to make it?

[@johnbrittpottery]

You can do it with a two piece mold. Just do the top first then the bottom and leave a hole for slip. Get a slip casting mold and look at it first.

[@RoyAndrews82]

Very nice video. I was just wondering.. Can you use this mold to cast Silver? I need a high detail mold for silver casting.. Would this work? (+1 : 454)

[@mylolzers]

I would also like to know if it work by too hot if i cast brass in it.

[@WarriorSkaldr]

According to Wikipedia (look up Plaster mold casting), it will work for anything non-ferrous(iron). I've seen people on KZbin use it for aluminium and copper casting. Brass (made of mostly copper) and Silver, iirc have melting temperatures close to copper so I think it should be fine, just do a little research.

[@chimpichompi4690]

Thanks! Nice and clear. Just what I needed.

[@sueheald7815]

Is it plain plaster cause I was told u need lots of chemicals.

[@johnturnbull5103]

Hi are there any issues about molten lead and moisture content of plaster molds . Do they need to be baked or fired before pouring the lead ?

[@centaurus777]

They must be fired or they will explode with contact of the hot metal

[@munchegod]

I am pressing clay skulls and they are getting stuck. Any tips on getting the clay out? As it gets larger it gets very difficult to get my skulls out is there any lubricant you would recommend?

[@FIREassassin1000]

Can this plaster be used the cast metal?

[@CoolKoon]

FIREassassin1000 It depends on the type of metal. According to Wikipedia it can only be used for non-ferrous metals (and obviously ones that have an even higher melting temperature than iron itself): en.wikipedia.org/wiki/Plaster_mold_casting

[@mihirbenipuri]

Is there a way i can make a human skull mold easily which u know??

[@shelliharsha]

Is there a product u recommend to seal it?

[@kikigogoljuk5953]

Brilliant! Thank you so much!

[@enterBJ40]

cool! Now i know how to make plastic parts for my rig !. Thank you very much.

[@johnbrittpottery]

You can case many things in this kind of mold but it have to find out the problems with each material. Some use rubber molds.

[@chimpichompi4690]

Just checked your channel. Interesting. I'm subscribed.

[@johnbrittpottery]

no, you can cast as soon as it is hard.

[@munchegod]

Thanks for all your help!

[@betonidesigns3450]

Cool video, is that plaster, or plaster of paris?

[@Cate7451]

Use potters plaster as it is stronger.

[@sobizzr]

very nice video and tricks John, but I am just wondering if you are using the mold for compression casting? there seems to be no sprue in the mold to pour for metal casting or urethane or similar .. ?

[@jewelryandarts1081]

can you use leather hard or bone dry piece to mold with this technique?

[@johnbrittpottery]

Either, but if bone dry seal with something like shellac because the water in the plaster may rehydrate it and mess up details.

[@jewelryandarts1081]

Thank you so much, your videos are fantastic!

[@wongwongfavor]

hello, may I ask what kind of clay you are using?

[@catrina339]

it can be done but you have to seal off the plaster with a clear coat first. good luck

[@johnbrittpottery]

Various kinds. you could start with a groggy body.