Waste Mold of Portrait Sculpture

heyyo I'm Dana younger a sculptor in Austin Texas and I've got a video here for you about the waste molding process this is a really cool process where you can make a one-time-use mold off of a water-based clay original this video is also about my shirt getting very very dirty over the course of this project you're in for about twenty minutes here a video and I will try my best to explain to you all of the processes that you have to go through to get a cast from your waste mold I always go over my clay original one last time and make sure I'm happy with it because you only get one shot at the waste mold okay so your first step is going to be to create a parting seam you need this mold to come apart into two pieces so that you can get it apart and take all of the clay out before you cast plaster into it I like to make my parting seam with shims this is aluminum flashing that I buy at the Home Depot I cut it into strips and then I cut it as needed into pieces to create the parting scene when I am creating the parting seam I generally make a small piece on the back and that's the piece that I want to have come off it's a little bit smaller than the main part so that it comes off easily as I'm putting the shims on I like to kind of tighten up those seams and hold the shins together with some duct tape and this is actual duct tape the kind that's metal where you peel the paper backing off you can see that I've created the whole parting seam and I try to put it in a place that's gonna be as inconspicuous as possible mmm but it does have to go the whole way I like to use Puritan pottery plaster for my plaster project it's kind of a good mid weight plaster and it's I find it easy to work with you can see I added a little bit of pigment to the plaster so that when I create the two layers that I'm gonna use in my waste mold I can see the difference as I'm chipping it off not going to belabor the mixing of plaster if you don't have information about how to mix plaster that is pretty easy for you to find when I'm doing this part of it I like to just mix it quickly and I check to see if I have a good mix by sticking my finger in and looking at it to see if it's covered if it looks watery and thin then I probably need some more powder in my mix okay so I'm ready to start applying the plaster directly to my clay model I always start with the face plaster thickens over time and so I like to start with the most important areas first while the plaster is thin you can see I'm just blowing to get air bubbles out of the corners of the eyes and things like that this is a very messy process I've got some plastic bags on some of my other work surfaces and it's gets plastered everywhere it's also not a terribly fast process you have to move quickly I have to mix multiple batches of plaster and the idea is I'm gonna cover the entire sculpture with this first layer of plaster I'm looking for this layer to be about a quarter of an inch thick all over it's a little hard to gauge that but I generally am putting it on with a brush until it starts to get thicker and then I will sometimes apply some by hand once I've got a good layer on the whole thing I'm gonna add some texture to it when this is with the thickened pasty plaster at the end of its process and you can see I'm just glomming it on to the surface and what this is gonna do is it's gonna create some manual locks between the layers I'm gonna put a separator in between the layers and I want but I want those layers to stay attached to each other when I D mold and so those keys those chunks of plaster that I've added on there those help the two layers kind of lock together okay so now you can see I've mixed up another batch and I'm going to apply that to the back it is the same process I'm putting a little bit of pigment in that first layer and getting about a quarter of an inch built up and I'm adding the keys and so it has the manual lock and then I will have my first layer complete you can see I'm brushing it all the way out to the edges of the flanges sometimes scrape the edge of the flange because I want to be able to see that flange edge as I go through the entire process all right next step I've got some clay slip now this is just simply clay mixed with water it's kind of thin and I'm brushing it over the whole thing and this is going to create separation between my layers once I have that clay slip on there then I can come back with a thicker layer and build up my shell to a 1/2 or 3/4 of an inch and you can see I'm putting that over the whole thing all at the same time also scraping as I go to keep that flange edge visible but I want the plaster shell to be thick enough that it's gonna be strong when I D mold it but not so thick that I have to really fight it to get it off this is a rigid mold remember and so after I cast my plaster into it I'm gonna be chipping it off of the surface now on the back because this is the piece that I want to have come off I'm adding a little bit of hemp fiber I don't really need it on the front because I'm gonna be digging the clay out but this back piece needs to be able to withstand the pressures of me prying it loose from the clay original so I like to add a little bit of hemp fiber just to give that back piece a bit of extra strength I always take my hemp fiber fiber and soak it in water and then I set it into the wet plaster and then I come back and I add more plaster on top of that I like to keep my molds as tidy as I can without being super meticulous about it I am gonna destroy this but I do like to make sure that the hemp fiber is fully encased in plaster you can see that I like to use my hand kind of as a squeegee working across the surface now I have to come back and really scrape down those edges I'll use a shirt form tool or anything I can to make sure that I'm seeing that aluminum flange edge all the way around now this part you want to be really careful so I'm starting to create a little bit of space and I do that very slowly this whole process took over an hour I created a little bit of space I squirt it put some water in there put a wedge in and I work all the way around until I've got a good amount of space around the whole piece and I know that it's gonna come off easily I never cry I'm never gonna stick something in there and try to pry that piece off you want to work very slowly now I start digging the clay out this also takes a bit of time a dug enough out that I can remove it from my armature once I've got the arm you're out of the way it's a little bit easier to get the rest of the clay out as I'm digging the clay out I tend to use a wooden tool because I'm less likely to damage the inside of my mold metal tools can scrape the inside and then that's more things that you have to fix so you can see I'm using my wooden tool and prying that clay out of there it generally comes out pretty easily but it always leaves some amount of clay residue behind once I've got most of the clay out then I take it over to the sink and I'm gonna wash it in water and with a soft plastic brush I just scrub the surface and that's gonna break loose all that clay residue and get the mold nice and clean before I make a casting I also want the mold to be really wet because I'm gonna use a plaster separator that is a combination of water and Murphy's Oil Soap and that's gonna soak into the plaster so you want the plaster to be wet already so here I am with my cup full of Murphy's Oil Soap and water the ratio I use is about two-thirds water to one-third Murphy's Oil Soap and then I brush that all over the surface I brush it on the flange and everywhere I can inside it there once I've got a good coating in there I tipped the mold upside down and I dump out the excess and let it sit and dry it generally takes about three passes of this to get the mold fully sealed truth be told on this one I probably cut short the number of passes with the plaster separator and getting the plaster chipped off was a little bit more work than it usually is so I encourage you if you try this to use plenty of plaster separator you'll save yourself a lot of time all right so I've separated I put in my splash coat of plaster I like to mix the my cast plaster my casting plaster by hand it mixes less air bubbles into it I put in the first layer with a brush I laid some hemp fiber in and now I'm gonna come back in and cover up that hemp fiber and try to get myself to a good quarter inch or so shell inside the mold while the mold is open it's a lot easier to do this when the mold is open if the mold did once the mold is closed it's very difficult to get fiber in there or to get an even coating again I'm looking to see that my plaster is well mixed that it's covering my hand and then I know I'm ready to use it okay so I put this layer in with a brush as well just tamping down that hemp fiber and getting a nice even coat inside the whole thing I don't worry too much about keeping it off of the flange I just work my way through and then before I'm ready to close the mold I can scrape that flange off with a plastic scraper so it's a messy business you can see my shirt has gotten very dirty it's going to get dirtier all right I'm doing a test-fit see how it looks okay let me show you that one more time in slow motion you don't want a dilly-dally but you don't want to rush it you just pick up the back and set it down where it goes give it a little jostle to make sure that it's keyed well in place just like that nice and easy once it's seated where you want then you want to come back and put some straps or rubber bands or something to hold those two parts together gotta get it really well bound together now I'm not gonna fill this with plaster what I want is a hollow shell it's a lot stronger when it's hollow now my camera died when I was doing the slush casting part of this so I'm gonna just slow this down and show you I throw a bucket down I pick up the mould and set it in the bucket and then I'm gonna pour some plaster in there trying to pour it down the seam I pour it down the seam I roll it around and then I pick up the whole thing and dump out the excess plaster you always want to dump out the excess plaster otherwise your head's gonna be solid and heavy and the body will be hollow and light and it's gonna break at the neck it's really important as you do these slush casting layers that you pour in plaster roll it around really good all inside of there especially on the seams and then dump out the excess okay here goes I know my head's in the way but you get the idea I dumped some in I took the mold so that it rolls down the seam as I pour it in and then I pick it up and dump it out okay I've done that a number of times I've thickened up the bottom edge by hand so that it's good and strong and it is time for the D mold now I'm gonna take all my straps off and then I just simply start chipping away at it at the seam now that those two layers that I created in there those two layers will separate from each other and I see that light blue layer down by the surface it's hard to see that in this video but as you're doing this process you'll see it and that means you're getting close to the surface and you need to be careful you don't want to destroy your casting it's inevitable that you're gonna do a little bit of damage to it a few little gouges here and there and those are easy to fix we'll take a look at that a little bit later now if I'd used more plaster separator I probably would have this coming off in bigger chunks this cast has of this sculpture has a lot of texture and so the texture was sort of grabbing on so it took me a little bit of time to get it all off of there I start with a big screwdriver and knock off the stuff that comes easy and then I start to work with a small chisel often not with a hammer and just removing little bits at a time by hand it should just flake off of the surface so it's just surface tension that's holding it on there the Murphy's Oil Soap and water plaster separator that we used means that your casting is not bonded with the mold but it does have surface tension and so you just have to gently go through and pry off all the little bits it takes some time it takes some patience but you can do it it totally works and this is a very cheap way to make a mold compared to making a rubber mold this is a very fast and very cheap process this whole piece the waste mold and the casting took me a little less than one bag of plaster so about 25 bucks I think that's pretty cheap so I just take my time and I work my way around and get all of that plaster off and into the trash can I can use a plaster tool I can use a chisel it's the screwdriver anything that works I can change my light around and that will help me see that light blue layer I like light blue because it's not super noticeable then when I come back and put a finish on the sculpture if there's little bits of that still left on there it's not real obvious that's why I just put a little bit of pigment in okay now the mold is off and I've got a plaster casting there's a little bit of damage to it and so I need to do some patching when I go to patch I always really soak the area you want to make sure that your casting is really well soaked before you start patching so that the casting doesn't leach all the water out of your fresh plaster you're putting on top of it when that happens you get a consistency difference and your patch will be harder and darker than your casting and that's not ideal so you want to soak it really good and then I generally use a plaster tool which is just a very thin flat oval shaped piece of metal I scrape it nice and clean so that I get a smooth edge and then I just trowel it onto the surface following the contours of the form troweling it on and then I'll use a little bit of the spray bottle water to soften those edges and this is an art like anything else takes some practice and you just kind of have to keep doing it until you get something that you like I had a few little spots that I'd hit the surface with my chisel and so I just needed to fill those in I use my thumb a little bit the thing you don't want to do with plaster is to sand it when you sand plaster you just kill the life of it so I don't recommend it it's better to add fresh plaster trowel it back with your plaster tool or chisel or something like that if you don't like the way it looks just scrape it back but don't sand it because it will just make things look bad it's a subtle business and this patching took me some time this whole process took me about six hours start to finish and here is my plaster cast that I got from my waste vault thanks for watching

Channel: danayounger_sculptor

Views: 21,861

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Id: t6d10ngvSYo

Length: 19min 42sec (1182 seconds)

Published: Fri Sep 13 2019