MOTHERMOLDS FOR SCULPTURE successfully open the mold and reassembly for a perfect seamless casting

Hey there YouTube this is John Burns with John Burns Fine Art where I teach you what I know about sculpture. So today I want to cover mold making once again. Hydrostone mother mold with fiberglass. Let's get to it. So while I'm working my magic with the silicone here I just want to say thank you for watching my videos it means a lot to me. If you haven't subscribed would you please subscribe and select all notifications. Don't forget to like the video and please check out the description down below. It has my social media links where you can see more of my work and in the description below you can see if there's any materials that might be relevant to you. If you do see anything that you're interested in I encourage you to go ahead and make that purchase and get started on your sculptures right away. So in this part of the process we have the paneling nails all inserted where we've determined our parting line to be. And I take strips of oil-based clay that's just a tube that I've rolled and then flattened out and trimmed with a straight edge. I put them on the one side of the nails so the surface side that I'm going to mold I leave smooth side out you know. The back side here doesn't really matter what this side looks like at this point. But I just use a piece of clay there on top of the nail head and that keeps that secured. So I'll just work my way up here and then I will manipulate the clay to have it follow the contour of the form. This center section where the pipe is going into the sculpture I have in another video called removing the armature pipe and I show how to do that there. But in the meantime we are going to work around that area and after we have this all set up we'll make the one mother mold half so it comes off on that side. Then we can take the clay and the nails off and make the second half pull off on this side. Okay my hands there suggest how the mold is going to have to come off the form to come off because of some slight hooks in the arm right there. I will put some clay in there to help reduce that. And sometimes it's okay to leave gaps between the mother mold and the rubber if the rubber is thick enough to support itself. So as I put this clay shim or wall up against these nails I can use a hard blunt object like the back of my fettling knife handle and kind of push the clay from the opposite side while I brace it with the handle. And then that way it helps line up with my parting line a little better and it buries the nail and creates a little more rigid of a wall. Then I can use a little piece of clay to help kind of bury that further. And of course it leaves a little bit of smudge marks and anomalies on the show surface side which if you want to leave them that's fine that acts as registration but if you're particular you can go back and smooth that out that's fine. And you'll see where your clay walls come together you're also going to have little areas to clean up anyway to smooth that out. So I'm working my way up here and this can be where it gets a little tricky when you're working around curves. What I would like to add here is the note that when you create a little circle like that make sure that the mold is going to let that go. It would be nice ideally if that center section that you're balling up to be pulled straight out. So if you lean that wall inward towards the center it's not going to do that. But you know the beauty of this method is that you can manipulate the clay wall as you see fit and then join it and you can cut it just how you need it. You need to cut a little extra to tuck it in there to fill up a hole you can do that as well. To go beyond the fact I create a condition for myself and dwell in it and think from it instead of thinking of it. For the great fallacy of the world is perpetual construction the third occupancy. Create and create in my mind's eye all kinds of lovely things I would like to realize but I never occupy them. I do not penetrate the state and go right into it and give it too big reality. But I know and you know and it's not difficult to understand why. The sense of touch is something we believe in more profoundly than we do in the sense of sight or the sense of hearing or the sense of smell. So I tell you facts are the flood. That's the damage. There was no other kind of flood. We are actually inundated with the facts of life. And these facts we change them every day. Today this is the cause of so-and-so. Tomorrow that's nothing. So it's another cause we found. And then the next day another cause. But while we have among the next cause we believe that to be the fact. And we worship the facts. So I tell you all things are in the human imagination. Man is all imagination. And God is man. And exists in us and we live. The eternal body of man is the imagination. And that is God himself. There is no other God. It's all your own wonderful human imagination. And the one thing the whole vast world aches for is the awakening of the imagination. And when it comes it comes with the birth of the promised child. Which sets a man free from the horrors of this world we call the world of nature. And I'm just finishing this up here. Bringing this wall down. You can see how I kind of curve that clay and pinch it. When I get it close to the silicone I just kind of give it a little squeeze. And that helps draw it in a little closer. Closes off the gap. And when I'm done I'm going to take my wooden tool, wooden knife. And go ahead and smooth that clay wall up to the form. In essence what we're doing here is creating a shim. So that as we build up the plaster and applying the bandages. We're creating the two halves. And this is how they're going to be bolted together. Okay so I'm just finishing the little pinching there. And I've got my wood tool. And it almost looks like I'm tracing along the edge. But what I'm doing is forcing a little bit of that clay at the bottom. Up against the surface. And that is in essence sealing it. So that when I apply plaster I don't have a lot of bleed under. I mean it's just more to clean up later. But at least this way I'm going to have what I can expect to be a clean edge. A nice parting line there. And you can see I didn't show this. But you can see how I drove a wall out there on the base. And of course the plaster is going to flood down. So I want to make sure that it's not going to roll behind the sculpture. That is part of the parting line. The bottom there. And I'm using just a regular petroleum jelly. It can be Vaseline or any brand. It doesn't matter as long as it's petroleum jelly. I've even used some vegetable shortenings. Things of that nature. But Vaseline is the best. It doesn't bleed through the plaster. And it doesn't dry out and shrink. Like vegetable oil does. So this part of the process. Applying the Vaseline helps the plaster let go per se of the silicone and the clay. If you use water-based clay you can also apply the Vaseline to the water-based clay. But you want to be really careful. Because when you create that mother mold and you have your two halves. It will want to fall off the sculpture on the other side while you're working. So just be mindful of that. If you don't use the Vaseline sometimes it has a tendency to really grab. And it will let go. But you'll see remnants of the material on the plaster. So you'll see sometimes little remnants of the water-based clay. Or remnants of the oil-based clay. Things like that that are trapped in the plaster. Nothing wrong with it. But it's good practice to use the Vaseline so you don't forget on the second half. You're just in the habit of remembering to grease everything before you apply plaster. Okay so I don't know if it's really obvious what I did here. I had to wait until it really started setting up. I let it sit for probably 10 minutes. After I sifted it over the water I let it sit for about 10 minutes. And it was super saturated. You saw that I took this clay off. So basically this mold's going to be done. So this one here it was just looking too messy for my taste. The surface quality. This is still a little choppy but I'll be okay. And I tried to paint one last layer on here and let it kind of run. So I have something smooth to write on. I can put the name of this thing right there and date it. But I used a brush and I used this bottle. Just water. Tap water. And I just kept spraying it and then running the brush. And that's how you can keep this moving. Because if you just use your hand or use a brush and you're trying to apply this while it is like really starting to do that final kick where it's getting hard and you can't apply it anymore. It'll have a real crumbly look. Well I didn't have my spritzer bottle handy. So this time I did. I mixed up another batch. Applied it. And when you spray it you can keep it moving. And that does not affect the hardness level of the plaster that I've seen. Just don't. If the plaster goes dead. Meaning it's kicked and it's crumbly and it no longer has any fluidness to it. Like this here. This is no good. I mean I'm playing with it but it's so short. At this point there's no more plasticity. Don't try to spray that with water and smooth it out. Just get another batch going and try again. So that's my tip. Water. Brush. You can get a smoother surface. I want to add one more tip. When your gloves and things like this are covered with plaster. Don't rinse them in the sink. Just let them dry with the stuff on there. Or have a slot bucket. If you need to rinse your gloves off. A slot bucket. Just full of water so you can rub your hands off in it. And get most of the plaster. I mean I'm talking 99% of the plaster off your gloves. Before you go over to the sink. It's much better. Because if you even take a little bit of plaster. That is still liquid and dump it down your drain. If that seizes up in your pipe. You're going to have a really expensive. You know you're going to be paying somebody to fix your plumbing. So just let it dry. And you can break it off and put it in the trash. Or have a slot bucket to rinse your hands in. And over time that slot bucket will have the suspended particle plaster. Plaster particles and it'll settle down to the bottom. And you can skim off the water on the top. And then just let that settlement at the bottom. That sediment. It will dry. And you can dump it out into the trash. So either way. There's safe ways to do this. But this is starting to get really warm right now. So it is starting to cure. And we're just going to take a coffee break or something okay. Or try to figure out what we're going to do next. All right so I've got my mess cleaned up. And I want to show how to prep this for the next part. But I want to point out that you know. It's very difficult to work vertically with a mother mold. Because the plaster naturally as a liquid wants to fall. So you're kind of in this weird place trying to keep it going up. But so I wanted to lay it down on its side. But I can see by evidence where some of this plaster has dripped over. It's up against this clay shim. That it was there was a gap there. And then when I pushed it back. I realized there was a space underneath the front. And I what I deduced is that this is moving slightly. Just like that. So I can twist the sculpture this way a little bit. It's pivoting right here. And what that ends up doing is it's like kinking the sculpture. And that will ultimately cause your. I've had this happen on a different mold. And I wasn't aware at the time. So you want to make sure that it's straight. Because even if you end up getting your two mother mold pieces together. What you've done is aligned the silicone jacket to this one. And then you twisted it so it's out of shape. And then this side will match the new silicone position. So when you end up cutting it open. It never wants to lay right inside. And that's what happened to my other one. And I have gaps in it. And it causes leaks. So even though that seam line can be cleaned up. I can go through and clean up the inside of the mother mold where it leaks through. It's something that should be avoided. So I'll let you watch me clean this up before I go in there and shim up the second part. What I'm hoping to do here is create a circle around here. There's a slight black line. And I'm going to take the clay and make a wall around here. Because in another video I want to show how to patch up this pipe. It's a real nuisance when you're trying to make molds. And you pull this out. And you just have like a hole in the back of your sculpture. That you have to go and fix up every time. So in a related video I'm going to show how to cut this open. Clean up the back. And then reseal it with silicone. And then you can put your third window. Or your plaster mother mold on top of it. Which can eventually be incorporated into one of the other pieces. Or it can just be a loose piece you know. But either way it'll just be less work. And in theory hopefully all you'll have to do is clean up this thin line. Where you patch your work back up. You won't have to go in here and plug it and re-grind the center. So that's good. Some people like to use aluminum shims. And then just do two sides. And then pull the shims out. But that leaves a gap. I mean ultimately it leaves a gap. If you're fine with that. Well more power to you. But if you want to have an airtight fit. This is how you do it. You put your clay shim. Or you can use cards or pie pans or you know. If you want to do the aluminum shims that's fine. That's fine. But the idea is that you remove it before you do the second side. So if you use aluminum shims. Throw your plaster on. And then pull the shims out. And grease up your plaster. Because that's what I'm going to have to do. I'm going to have to take more Vaseline now. And put Vaseline on here. And then once I have Vaseline on there. I can throw that plaster on there. And then have the tightest airtight seam. And these gaps. These air bubbles. You just fill that up with Vaseline. And make it smooth. You don't need to get plaster in there. That'll just make it more difficult to pull apart. So just smooth it over with Vaseline. And you don't need registration marks per se. Because there's enough you know anomalies in this. They'll lock together fine. It'll register fine. Just having the waves to follow along the figure. So I just want to say. I'm going to go ahead and finish this. Because you already saw what the other side did. It's not that important. I'm going to drill some holes. Just to keep it clamped together. So it doesn't open up on me. It may fall open. Because I put a release on the silicone. But the next step is to lay this down. And get the black pipe. Or in this case the galvanized pipe out of her back. Then I'll show how to patch this up. Which will be in another video. But this will be the next window. Okay so these are plaster bandages. I found this technique to be very useful. So before you lay down your fiberglass bandages. Use the plaster bandages. Just lay them straight into the Hydrostone. To hydrate them. And then apply them. That helps prevent the running and the sagging of the Hydrostone. So do that first. And then you create a nice first layer. And you can go back and lay your fiberglass bandages on top. So here once I've determined I have a nice thickness. I use a sharpie marker to pre-mark my holes. Drill them. Get the bolts in there. To make sure that the mold stays together as I work on it. Last thing you want is for a mold to fall open while you're working on it. So bolt it together. Get your edges cleaned up. And I use a variety of tools. The Sureform there. I use a knife. A folding knife. Just an old cheap Walmart knife. You might find useful to help kind of work that edge. Be mindful that your hands are going to be in the way quite a bit while you're using these tools. So have a first aid kit handy if you're a little reckless. This plaster has completely set up. Cured. It is at its hardness. So the Sureform isn't cutting it. The blade that I'm using is old and I didn't have a new one handy. So I elected to go with a cutting wheel and Dremel. So there's a variety of ways you can do this. The Sureform you can use a Dremel cutting wheel. Let it walk itself. That's just an extra tip there. Pre-mark the line. That way you know exactly where to cut. Do you see all this extra dust coming through there? Have a good ventilating system. So with that first pass of the cutting wheel, I just used my knife and then kind of pried it till it popped. Make a second pass and pop up what I can. Use the Sureform to level it off. And the best bet is to really take the mold outside. There is quite a bit of dust that you'll find in the oddest places. You can set up a box fan with a filter on it so that as it sucks the air through, it'll help trap that. Go ahead and turn it over. Mark your line. You can use a Dremel wheel to cut along your line. And then you can get a Sureform and clean it up. I really find that marking lines ahead of time is kind of the same philosophy of measure twice, cut once. So once you get this all set up here, we're going to get ready to flip it over and get a base cut out for it. You'll see that the board isn't quite a perfect fit, but we're using a ruler to measure across and find the measurement that's going to fit the board that we have here. You can trace around it, get it all scribbled out so I know exactly where to cut. I'm going to take it over to my bandsaw and get it cut out. Again, I'm using the Sharpie pre-marker I'm going to drill. Take it off my Lazy Susan, put it over the styrofoam there. And then that way, I don't have to worry about that after I cut it out. I try to get all my markings done first and then lift things off and do all the cutting. Okay, check it out. So I've got carriage bolts here. They're just the bolts that have a square underneath the head there so that they go into place and they don't spin while you're spinning them down. So anyway, when I put those in the board, you know, just give them a good whack with a hammer, you know, hanging over the edge of the table or something to help put them in there. So I know this is the back of my mold. I got it lined up here. Sometimes it's not quite so easy to get the bolts to start through the silicone. So I know where the holes are. I can see them here. So I'm just going to, my phone would stop, I'm just going to do a quick little hole and that'll open that up so that those bolts can go through a lot easier, you know. And Vaseline, just go over the top and that'll help, that'll help get it to go through. And if it's still not going through easily, it's probably because you didn't drill your hole straight. So there we go. Okay, so I got my wing nuts. If you want to put down washers, feel free. That'll keep you from screwing into this. And if your plaster is a little softer, use washers because this will dig right down into it and chew it up. And then you'll lose your grab and you'll have to drill new holes. So, and if that happens, you can get really wide washers and put them down and that'll kind of act as a, if I can have better words, like a splint. So this mold is pretty much done as far as construction. At this point, we're just going to demold it. That's the next step. So I'll get my splitting tools and, and the splitting tools are nothing more than, let's see, auto body panel removal tools. I can list those in the description. The carriage bolts, I will list those in the description. You're going to see a lot, a lot of other things in the description that are going to be useful in helping you here. So I myself realized I need to get new blades for my sureform. Those are getting pretty dull. They felt sharp, not sharp enough, so I need to get some blades there. And anyway, I'll try to get this stuff listed in the description for you guys so you can find it and stick around. We're going to get it demolded. That's the next video. Happy days. Happy days. Something else I'd like to mention here before we get going is that when this video goes live, I try to stick around and answer any questions that people might have if you got any questions about this. And the way to know when these videos go live is to hit the subscribe button and turn the bell on so you get all notifications. I don't release more than a video a week. Sometimes I only do two or three videos a month. But when it goes up, if you want to see what's up, I'll be there and I'm willing to answer questions. So for the first half hour or so, I may go a little longer. Yeah, subscribe, get some free questions answered or get some questions answered for free. How about that?