 This is large two-piece knife edge. This is a piece that Moore worked on over the years through the 60s. It worked on many things that Moore was doing at the time, organic objects. There were pieces that were enlarged from flints and bits and bones. You've got sort of the sharp edges of the bones, sort of cut bones. This piece is about two and three-quarter tons of bronze. It's not massive, you know, it's hollow, but it's a fair weight. Siting this work in such a prominent spot for Moore was hugely important as it was having major pieces or any of his work in major sites around Britain and especially London. It was about making the almost unapproachable work approachable for the public and there's no more approachable place than outside the House of Parliament. For him it was hugely important. The statue was gifted to the nation. The minister at the time accepted it on behalf of the nation, the donation, and it was installed. And the maintenance instructions were to wash it occasionally with fairy snow, that's in the file. But unfortunately over time the Ministry of Works changed and of course became partially the Department of Environment. Responsibility just disappeared really. So the sculpture sat here but nobody really cared for it at all. As this became known really as the most damaged, the most badly presented sculpture in central London. It's pretty horrendous actually. I mean, we're now looking at a surface which is two-thirds green. It's naturally oxidised but there's graffiti over the entire surface. Moore put in his own texture. We've now got other people putting in their own texture. It's lost that beautiful gold quality that had the subtlety of the shading in there. All of that has been lost because it's naturally done what it wanted to do itself. The lacquer itself has broken down. It's peeled. I've not seen one quite this bad for a very long time actually. Eventually Frank Doran MP who chairs the Speaker's Advisory Committee on Works of Art in the House of Commons laid a question to the Minister for DCMS asking who was going to care for this statue. And the Minister replied that would the House of Commons be willing to take on ownership of the sculpture and take on its care. And we were delighted when the House of Commons agreed to do that and it entered the Works of Art collection, which means that we can now care for this sculpture. To conserve a piece like this, we basically have to get back to the bare metal. Unfortunately, because of the damage that has been done to the surface, it's not something that you can do selectively. Bronze being what it is, it's started to corrode, turning darker browns, going through to green. So as now it's got a very almost camouflage appearance to the surface where it should be quite an even, rich, golden, yellow, honey colour. There's slight variations into the textured surfaces. It was very sensitive about the surface coatings of his sculptures. He not only was interested in the form, he was actually interested in the colour. And the colour on this one has gone completely. Our approach would be to remove all the protective coatings. Well, what's left of them? Remove the wax, remove the lacquer and get back to what remnants are of the original patina on the surface. As you can see, the surface of the bronze has got all this graffiti which, as you can, it's not done with a green pen. What has happened here is people have scratched their names into the surface. This has actually gone through the lacquer and we're getting preferential corrosion. This is copper corrosion here. The processes for cleaning the sculpture, initially we will remove the wax. That's removed with a steam cleaner. The wax is this dark area here which has got the black colouring in it. The steam cleaner will remove all of that. Then once that's actually gone, we're going to remove the lacquer which is in these yellow areas by applying... It's a water-based paint stripper, basically. It's friendly to the environment, may I add. And then once that's actually been removed, that will be removed by hand. Then when we've got it right back to body's bare metal, we will start to resurface the metal to remove the graffiti and any other marks on it. The emphasis is going to be on minimum intervention. We want to remove as little of the original metalwork as possible while getting rid of all this graffiti which has etched its way into the surface. The process that they're carrying out at the moment is the removal of the lacquer. The green on the surface there is a water-based varnish remover which has been on the surface for around 36 hours. We're just scraping off the surface now and it should be taking 99% of the lacquer with it. And then after this process has been carried out we'll steam clean the surface. They're all unique. There might be three of these in the world but there's only one in London. They've all got different surface coatings. They've all been put out here at different times in different conditions. It was very exciting to see what's being revealed beneath and beginning to get an idea of the colours that it will end up with. But also you can see the challenge ahead. You're never really sure what you're going to find underneath. As you can see already there's quite a mark difference between the area that hasn't been worked on and the area that has. You start to get that luscious luster of the original patina that Henry Moore intended. I'm hoping that when the hoarding comes down people will be actually really quite surprised as to how the sculpture looks. Striking, hopefully very lush and people will be sort of shocked in some way. This work really is quite iconic I think within this area of Parliament. Everybody is aware of this sculpture and to an extent it's become part of the landscape but I think once it's been conserved people will be very positively surprised and will hopefully start to really appreciate what they've got here. The sculpture was originally gifted to the nation by Henry Moore. He wanted many of his sculptures to have an appropriate background and for this sculpture he thought the House of Parliament was an appropriate background. It's in two parts. There was a gap in between where you could see the House of Parliament and that has given a different view of Parliament for anyone who's interested to see it. It's been a backdrop in hundreds of interviews of politicians on this very site and for all sorts of reasons it's a very important piece now for us and we are delighted and very happy to have it in the collection. This is wonderful isn't it? The view of it is fantastic. I mean the sculpture is about that the space between two forms. A patina is a chemical alteration of the surface which we can create colour from and once that's done you can seal it either indicate using a lacquer which was done before or in our case now we're going to seal it with a wax. The patination process is a chemical process that all sculptures go through after they've been cast in the foundry and you apply chemicals to the surface and you can create a whole range of colours from blacks to greens to blues to whites in the case of more sculptures they have a very pale patina with some darker areas and that is done usually using heat and cold patina applications the time it takes is very difficult to judge and that's why we had to allow in this project an adequate time to create this surface. The one thing that more sculptures particularly these ones that were taken from bones and fossils and pieces of chalk are that he wanted to get that mixture of texture from smooth surfaces to rougher, less reflective surfaces and he did that not only by working the surface to give that but also he then patinaed and coloured the surfaces so that accentuated the difference. What I'm doing at the moment is applying a very weak solution of ferric nitrate which when the bronzes heated gives these very subtle burnt sienna colours to the surface with a patina like this that's so thin you really need to apply a little bit of time and when I've finished this yellow colour we'll have a subtle orange tinge to it which just gives a little bit more warmth to the surface of the bronze the good thing about it as well is it will hide some of these marks in the surface from when the piece was cast. What we're aiming to achieve when we complete the job is to get life back into the sculpture more sculptures because they're a mixture of this tooled surface and the smoother surfaces it's all to do with the play of light and so that is what we need to achieve when we finish and I'm sure now we will get there but at the end of next week it'll be very good I think. It's wonderful to see it because it was looking very sad some of the patination had gone there was graffiti on it it looked very sad and sorry for itself and the team has been tremendous and we've seen a huge difference already and we're beginning to see the vision that Henry Moore had for this site and for his sculpture. Dividing a form into two or more parts you relate it more closely to landscape so you have the cliffs and valleys and chasms in this case that you might find in nature and of course his work comes from natural objects. The knife edge refers to this part of the sculpture where the form comes to a very fine blade and that sharpness derives from the edges of bones in this case particularly the bones of birds Moore really liked the fact that with bones you have very solid forms but also very fine edges and so there's that contrast between a very elegant line and almost a fragility but also a real toughness in the material. This sculpture is one of a family of forms that come in different sizes. It's typical of Moore's work in the first half of the 1960s which famously are based on organic forms that he finds in the landscape so in a way it's kind of archetypal of Moore's practice at the peak of his career when he's being commissioned to make or position sculptures in prominent places all over the world. What's unusual here is this strange dialogue between these sort of beautiful natural curves of his stones and bones and the sort of the gothic decoration of the palace opposite. Avondale Green is a key location right next door to the houses of parliament and for decades it's where interviews have taken place it's been the backdrop for life in parliament and here we are next to the Henry Moore statue which has stood centrally it's been there over that 45 year period and has witnessed the many comings and goings. We're now at the waxing stage which is after with patina bronze you get a wax coating which protects it from the elements the idea is it will stay this colour instead of deteriorating the challenges with a piece like this is the variation in surface you have the very smooth areas which are the trickiest to work on they're less forgiving than the rough textured areas that you might get with more historic bronzes it's got a very contemporary well modern finish you would say lots of varying colours which are quite challenging to achieve. The colour is beautiful it's absolutely as it should be the tones between dark and light and highlighting certain areas that project and darkening the crevices is exactly what Moore would have wanted. I hope now it's in the condition it was supposed to be people will see it again we become very complacent and blind to the things that are around us and as you walk through London or travel through on the top of a bus there are fantastic works of art a number of them by Henry Moore all over the city and anything we can do to make people more conscious that art is actually a part of their everyday life without them realising it is the better. The most satisfying thing about working on a sculpture like this is the transformation you look at the pictures from before and how it was so badly vandalised and it had all the inappropriate coatings on and then you can look at it now and it's as good as what you might find in a museum which is really satisfying. Because it's just been restored and it looks absolutely superb people will see it fresh and new.