Hywel Pratley talks about the silicone stage in the making of the statue of the late Queen Elizabeth II which will eventually be placed in Oakham
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00:00 So here I am again with sculptor Howell Pratley at your studio. We're at the next stage of the statue of Queen Elizabeth II, which is the pink mix.
00:11 Absolutely, yes, morning. The wonderful Naomi and I, there's Naomi over there.
00:18 Hello Naomi, good morning.
00:20 I'd like to say she's helping me make the mould, it's quite the other way around, I'm helping Naomi make the mould.
00:25 Naomi Edwards of Edwards Mouldings and Castings. We've done one layer of silicon, the pink is the colour of the catalyser, which makes silicon rubber set.
00:42 So we've done one layer all over, if you look around you'll see pink queen. Unfortunately we've had to decapitate her because when you're designing moulds you have to think about access in the casting of the wax cast, which is the next step.
01:03 Yes. So for ease of access and just to make the mould lighter, you sometimes want to design divisions in the mould, so we've cut her head off and closer inspection shows you that we've had to cut two of her fingers off for ease of access.
01:24 And I'm now mixing up, sorry if I'm distracted, 600 grams of silicon for Naomi to bead on a division wall. So 600 is 60. Sorry I'm thinking aloud.
01:41 Yeah, that's right, yeah.
01:43 60. Do you want to explain the wall Naomi?
01:46 Yeah, sure. And then what happens is, yeah, so once Hal's mixed that up, he will add a fixotropic additive to it, which will make it really thick and gloopy so it doesn't slump on.
01:57 Okay.
01:58 And then we basically put it in a highball bag, as if you were icing a cake.
02:02 Really? Seriously?
02:03 Yeah, pretty much. And then we pipe on a bead, and that's what we've done here on this bit here, so that you can see. We pipe on a bead which sticks to this and essentially gives us a nice edge, like a nice sausage that we can then slice into to put these shims in.
02:25 Right.
02:26 And the shims are what make the mould divisions, which is so that the mould can actually come off from the clay queen, so you know, it can actually fall away like that.
02:35 The bobbles are little registration points, so that each side connects together easily.
02:43 Okay.
02:44 So yeah, that's what the bead is for. We generally pipe it on, let it cure so it goes hard, and then use a scalpel to cut through, and then each little section of shim can slot in.
02:56 And then we tape it up, and then what will happen is we can start building our fixotropic layers.
03:02 How long does each layer take to harden?
03:05 You've got the, it'll basically be the curing time of the silicone, so half an hour.
03:12 Oh, it's quick.
03:13 Yeah, it's quite quick.
03:14 We have to work on this bucketful now, we've got what, 15 minutes to work with it before it starts getting a bit more viscous, and then...
03:22 It's not so malleable.
03:23 It's not so malleable, yeah.
03:24 Yeah.
03:25 So that's sort of time pressured, and then it will set.
03:29 Yeah.
03:30 You say an hour, did you say an hour?
03:31 Probably half an hour, it starts to get more and more gloopy and harder to work, and then it will gradually cure completely and it will be like a, you know, a hard rubber.
03:40 So what you see on the Queen's head, and all around you really, is the first liquid layer that we've brushed on, which is otherwise known as the detail layer.
03:49 Okay.
03:50 Or the capture layer, so we're capturing all the forms.
03:53 So the fact that it's dripped on the outside makes no difference at all, it's the inner form that you're after, aren't you?
03:58 That's the true negative that's important to capture later in the wax cast, in the lost wax process.
04:04 So provided you get into every crevice at this stage, you'll capture the likeness of the clay.
04:10 Exactly.
04:11 And then the taxotropic layers that we build on after that are purely to give the silicon some structure and some strength, so that you can then peel that away like a marigold glove and you've got a nice thickness to the silicon.
04:24 And that will be cradled by a fiberglass shell.
04:28 Yes, well that's the next stage.
04:29 Yes, that's the next stage.
04:30 We'll come to that, yeah.
04:31 So this is day three, we don't know of how many days.
04:35 Ask us how we are.
04:36 How are you?
04:37 Tired, I presume.
04:39 Feeling like, feeling two or three years older than we did two days ago.
04:42 Feeling really old.
04:43 Yeah.
04:44 Yeah, we can't quite believe how much work has already happened and how much is ahead of us, there's quite a lot.