HOW TO MAKE A COMPLEX MOLD for Sculpture - Silicone and Hydrostone / Plaster, Handmade Mould

So another thing I'd like to point out before I get started is on this the last time that we looked at it I knew it needed some things to be finished and I realized that this needed to be bent out a little more so I just gently moved this and the back here this is really what I wanted to point to. So the back looked kind of a mess really when it comes down to it. So I took a board and I put it up against here traced around it from the front side and used a squirrel saw to cut that out kind of buttered it up to the edges here and then I put clay in the cracks and that brought it out a little bit and I'm telling you if you do this with your clock if you do a clock in my case I had to bring the clock out another quarter inch from the wall which is fine because I broke my clock trying to work on it trying to get the weight right and I had to put a back brace on it to reinforce it so this all worked out well very fortuitous so there was a chunk missing here from a previous cut and I know that that's not perfect but it's up against the wall so I hit this with crystal clear also to help kind of seal the wood a little bit the silicone is it will go into a lot of tooth grain a lot of places it will replicate fingerprints so I just wanted to make sure that wood was sealed to help that let go a little better I went ahead and tightened up the edge to the bottom so and I have a base that's big enough about two inches going all the way around minimum to do a sculpture this overhang isn't terrible but it what's going to happen is when you run your silicone flange out and then you're going to do a mother mold on top of it you want to have that room for a foot especially if you're going to attach a bottom because some people like to put bottoms on their molds with a little plug hole so that you can put say like resin in there and then plug it and then slurry it around until it sets up like in a rotocasting machine or something of that nature so I just wanted to touch down on that before we get started let's go okay one of the things that I want to point out here before I go any further with this I did mix up another color and I put in some pigment so that I can tell where I've been on the sculpture you can see a color difference here of the original content color which is that orange color of the rebound 25 I put in a little of the the silk pigment s-i-l-c p-i-g is what they call it silk pig so they offer that through smooth on but I mixed in some red to give it a little darker contrast and this lets you know where you've been where you haven't been and I wanted to make sure that I got a consistent coat so I am going to put on another layer I feel as though I probably only got about a quarter inch thickness I want to get to about three-eighths in most areas not in all areas there's some areas in here where I'll plug that I'm going to plug that with some clay and that way that I have a little bit of play room as I'm pulling this off you know I don't have to just try to yank straight out of there I can play with it a little bit to loosen it up before I try to pull it out and in there also so I'll plug this when I do the mother mold and plug it over and hopefully in the other areas where there were some recesses I left a little bit of a niche here instead of just completely smoothing that flat to give this a little more room to kind of bounce into itself as I pop it out of there because this is more of that light bulb shape where a traditional plaster sculpture wouldn't let go this is the beauty of using silicone so with that said I have it on the back here I'll probably build like a support rib these flat areas tend to bow or sag inside of a mother mold so you can put little pieces of already cured rubber typically you want them to be shaped as something that could be grabbed onto but in a nutshell you want to have something that can hold this back to the mother mold really what's important to note here is I've decided where my seam line is going to be for cutting this open this is such a complex piece I'm not really afraid to zigzag over it but I've had enough experience with pulling molds apart to know that when you're handling the rubber sometimes it can get in the way and the weight of it and its bulk in your way actually can cause it to tear in some other areas so I feel like this is going to be the path of least resistance it's like trying to come down a mountain with a lot of ravine so I'm going to come up go over the feet over the hand up the arm I'm going to try to get it back to the back because we want to keep the show surface clean we really don't want the possibility of seam line showing on the front this isn't really that imperative with waxes although you want to keep the original as intact as possible without messing up the artist's intentional mark so this here is coming through the hair and hair is pretty easy to clean up and plus also with resins I want to add when you cast a resin it's kind of a one shot unless you're casting it in pieces assembling it and then doing a finished patina if you do something like a cold cast bronze you want to do these in one piece molds so seam lines are going to be very difficult to clean up okay anyway come over that will allow me to pull this out and this out without having this big bulk on the back we're trying to pop their heads out of this light bulb shape I'll take it around his back shoulder I'll bring it around over his fingers to allow the fingers to get free since they're sticking up and then I will bring it back down to this corner so I can have two halves of the mold this half essentially coming off and this half coming out so what I'm doing here is cutting a very shallow amount there into this seam that I've made and the straighter you can keep it the better I'm going to keep it straight not this kind of curve you know straight is better I mean there you may have to curve and that's okay so I know that I've got a line here it might be advantageous for me I'm only going to go to where I'm going to go here now but this point is that I want to try to continue this path up into here and now I can get the card to lay you know straight from here across here if I would have cut say this this way and that that way then I'd have to do something funky with the mold as I put it together so anywho so I know that my line is going to be somewhere like this is good then my line is going to be somewhere like that and I know that it's probably going to go somewhere up in here if I wanted to it could come clear up in here and that's okay I'll do that let's see what happens and I don't like it so I'm going to cut it okay so as I end up putting these together what I'm doing is stapling them so I don't have things clopping back and forth the first mold I ever made I used shims from like a pie pan they were aluminum shims and I didn't even fasten them together not even mechanically or you know with an adhesive or anything they were just there and I slapped down plaster and I'm trying to pull these shims out which made terrible gaps so that was a major no-no this here is just so that I know where my one part of the mold is going to be so after I throw down some plaster on top of this and this comes over and all the plaster is set what I'm going to end up doing at that point is pulling off this I'll pull it out and then on that side I'll only end up having the plaster which I'll grease up with Vaseline and then apply the next layer of plaster so I'll have plaster up against plaster it'll be an airtight seam and that's good oh when you cut into this do not make this all the way down you're only going into this ridge that you've made and if you have to do it on one that's only this here say like you're fixing somebody's mold or something like that you know don't go all the way through because there's a technique you can do that for the first like half of it but when you finally get down to the bottom I have a technique that keeps the the rubber jacket from just butting up against itself and falling in because that's not good what you want to do is create like a zipper effect and I'll show you in detail when I get there but as you are cutting that seam I go back and forth like so and it creates like a zipper as I drag that motion through and then when the two rubber halves come together it actually keeps it from falling in on itself and the seam line is pretty flawless it's just something you know you can knock down with the razor blade edge and barely ever find it so that's really good when it comes to editing your finals and you know having a more accurate copy of the original so that's what we're doing I'm just going to keep moving along here and hopefully we'll have something great okie dokie okay so as I'm going around this just remember that your cut I mean let me let me just start by saying this if you didn't want to use business cards you could take clay cut slabs of clay and work it that way this way is nice because it really grabs and it doesn't fall off and I can walk away from this and come back tomorrow clay obviously you'd have to wrap it you worry about the shrinking when you do put clay on this if you cover it you run the risk of it possibly shrinking overnight and then falling off and it's better to have a very plastic clay like a throwing clay or something like that when you do this so it'll stick but anyway right now we're using the cards and this is what we're going to use when you cut your seams here if you don't cut the seam exactly as you want it that's okay we're going to cover this with Vaseline like this part is kind of poking up a little bit and plaster will get under there which if I don't block it it's not a big deal I can just bust that piece off when I take these cards off on the next side but I've had to manipulate this also a little bit to make sure that I have more of a pie wedge if I create that light bulb shape in here I'm going to have a real heck of a time trying to get these two mother mold pieces apart so anyway try to create a pie wedge if you can get one half of that mold off the other parts by default will come off so I just wanted to share that with you real quick and I'm going around here and manipulating these as I go so have a nice overhang here and if these pieces like on this side there's buckling and such on the bottom side that's not a big deal what we're worried about I'm going to do this side first this is the side that I'm concerned about if this side ends up getting kind of weird and these pieces aren't coming together quite crisp that's fine because once this comes off you're going to have the reverse of this so this is what matters this is what matters back to work