I decided to keep the bronze in a fairly natural bronze finish, when i think if bronze i think of warm gold, orange bronze slightly tarnished like many public sculptures. I wanted a material that set quickly but could be poured. I bought quick set concrete and was bale to pour it in to a condom and set on the frame. With this method it often forms the shape and build up a column but with concrete when it is partially set i was able to remove this and smooth out the shape with out damaging the organic form.
I had to experiment with the right consistency to pour the concrete, as more water was messier, easier to pour but took longer to set. this meant i had to support the concrete in the form while it set, as it has a tendency to slip through the structure. Where as with less water it was harder to pour in to the condom but took less time to set. i decided to use more water
After the concrete had set the form actually looks more stone like than a concrete, which further emphasises the organic contrast within the whole form. The juxtaposition between the very natural forming of the concrete and the worked and manipulated bronze also plays into the dichotomy on the pieces.
I initially set out to have 3-5 inside pieces made of ceramic, after making the initial main piece i realised that how complex and difficult it would be to make 5 pieces and make sure they all fit due to shrinkage and glazing. I decided to keep my main piece as ceramic and make the other out of concrete or jesmonite, it would still involve the same process just without the slip casting and firing.
To create the ceramic i :
- Created a former, this was my wooden maquette
- filled a condom with plaster and set it on the same
- Gently removed the plaster from the frame
- Made a 5 part plaster mould from the inside shape
- used this mould to make slip casts,
- fettled the slip casts
- bisque fired them
- applied glaze
- re fired
- set in wax/bronze frame
This is the plaster mould after it had been used for a slip cast mould i ued this a a former to create the accompanying wax form after the original had broken. Although i used this to line up the cuts, i knew form a ceramic test that when fired to 1100 degrees Celsius the maximum the ceramic would be fire to it shrunk by 10%. SO although this was a guide i had made the wax to 10% smaller than the actual plaster form.
I originally was going to leave the ceramic a matt white or use a transparent glaze, but after making the decision to use concrete i wanted to carry on the tones of gray, making the ceramic similar to the concrete but different enough to show that it is a different material.
I started to look in to velvet under glaze. as they had a range from matt to satin depending on the firing temperature. they also come in a variety of colour with strong pigment.
i ordered a white, dark grey and dark green as this could compliment the gold tones of the bronze. I fired them to 1000 and decided that grey was the best option as it better reflected the colour schemes through the rest of the pieces.
After dipping the molochite shells for a week, the shells had got to roughly 3kg for the largest. Although it doesn’t seem like much weight they are very large figures with only a small hook to hold them by. This made them very challenging to dip but very impressive to look at.
Unfortunately at this point my schedule got very disrupted as the extraction for the foundry failed, meaning any wax work, the burn out or the bronze pour got postponed. I was at a very critical point and to be able to finish the project on time i need the foundry to be functioning. Dallas the foundry technical demonstrator allowed and helped me to complete my burn out outside meaning i could continue on with my forms.
This is a process where the wax and molochite forms, get places upside down in a kiln and the wax is burnt out in to a pool of water. It cools allowing it to be scooped out from under the kiln.
Fortunately a few days after the burn out the extraction was fixed and i was able to complete my bronze pour. Another reason why choose to use a casting method for the bronze was the fluid act of pour the metal. The concrete and plaster were poured forms, its very fitting that the bronze is also a complete poured form, it is one entity rather than several pieces joined together. The fact that both object have a similar way of pouring to create them to me creates a more cohesive sculpture.
After the pour, there is a lot of work needed to finish the bronze:
- Angle grinding- cutting off the risers and pour hole
- Air pressure gun- sanding rough edges
- Dremel- sanding down smaller areas
- Hand filing
- sanding with sand paper
- polisher- buffing and polishing
- patinating – chemicals and blow tortch
- wire brush, polishing
This is a picture of Patinating bronze. I used sulphur nitrate in warm water and sprayed on to the warmed bronze, then heated again with the blow torch. I repeated this till it goes from warm yellow to dark. it is very difficult to burn the atina and the bronze in this process, so it takes a lot of concentration and knowledge of when to heat and when not to. I went for a dark colour so i could buff back the high points of the structures to catch the light but to also look slightly aged, I did not want to over patinate it will colours so its takes away from the fact that it is bronze.
I also experimented with cold patina which is where the chemical is put in hot water an applied directly to the metal there is not heating with blow torch. This method works for small area or touch up, but for the whole form i prefer hot patina.
I started off lightly sanding the bronze to catch the the texture and organic nature of form i had created. However, the contrast was to stark and i then went in with a brass wire brush to smooth the colours out and make it have more of a natural bronze look. Bronze is a versatile material and will pick up what ever colour metal you are applying to it so with a steel wire brush the bronze would take on a more chrome colour. I prefer the more golden tones of the brass brush, so i stayed with this tool and waxed the pieces to lock in the colouring.
After making the wooden frame the next step was to to replicate them in wax. I have picked the lost wax process instead of buy rods of bronze because i want to create a geometric frame, but one that is irregular and organic. The central piece are free formed shapes except for the few geometric lines that cut into the form allowing it to fully sit in the frame. To reverse this and embody the dichotomy element of this project the frame is irregular geometric.
This design really challenged the boundarys of the lost wax process as the structure was made from 6x6ml wax rods, the structure was very large and difficult to support when adding the risers. Which is why It tough me some of the limits of the material, and what limitations there are to achieve the look i want.
I decided to make a smaller structure and sand cast three out planes to re-create the size of the main sculpture. This is a process of packing silica sand around a form building a up a mould to then create a negative space of the desired casting object. However, due to the mould sitting horizontally the mould did not fully fill. I decided to leave the height of the piece as this particular form will be the only one to have a ceramic centre and be a vessel which will make it stand out from the other forms.
Continuing on with the lost wax process, the other forms were all small or wide and low enough to support themselves. the difficulty with this process is due to the joining of the rods with a hot knife, as the wax is already so thin a lot of the wax was melting away, which made joining difficult. However, any thicker and the frames would look to big and wouldn’t be as elegant.
Making the wax form is a relatively quick process, the longest process is adding the risers and pour holes. The wax is very fragile and to support the unusual structures i had to create some unusual supports, this added a lot of weight to the wax during the molochite stage.
I set out to push my skills in bronze, the size and intricacy of the forms have certainly pushed my foundry skills i had to combat lots of hurdles to create a whole form that was happy with as two previous attempts had no worked. Although it was difficult this process was still playing to my strength rather then TIG welding bought rods of bronze. I don’t think there would have been an organic feel to welding as the amount of precision needed would have either looked to static or looked messy. The wax was worth the risk and experimentation.
I do not think i would have been able to achieve such an intricate shape, with cutting and welding Bronze rods. Although i worked out a lot of the main angles in my drawings and Maquette, i didn’t not feel confident in cutting the angles in the rod as it would be very difficult to fix. Wax is reusable and easier is not more delicate to work with, i also think the organic feel to the frames was a successful choice regarding the entire form and concept i am working with.
From the previous experiment of expanding ceramics i knew i had to acknowledged shrinkage. To test the shape of my structures and plan out measurements, i decided to buy strip pine to work out the structure.
I created this structures to form the central forms from plaster and to use as a guide when creating the wax structures. This way i was able to replicate the shape that fits the plaster form. I did not make this out of CAD as i want an element of fluidity. I wanted to create a form where each line is responsive to the lines surrounding it, which i think it best achieved through physical experimentation rather on a computer screen.
If i were to create a business or mass produce this technique where many designs would be needed i would work on my CAD skills to be able to mock up the designs in CAD, laser cut the pieces and then re cut them in the appropriate smaller percentage. However, at the beginning of this project the wooden frames started as mock ups that were actually used to form the plaster and then re created in wax.
The next challenge was to attempt to make a organic globular form. I played around with the idea of casting objects. However, finding objects that fir the frames would be very difficult and time consuming. Instead i wanted to make objects responsive to the form they are sat within. Plaster is a material that is poured as liquid and sets due to a exothermic reaction meaning it does not need, to be exposed to the air. Balloons or condoms are expandable forms that would allow me to set the plaster in a shape according to each frame. Balloons were a bit stiff and awkward to pour plaster in so i tired using condoms. The picture above are from testing this technique, and resting the plaster over a 8mm piece of acrylic.
I had already experimented with some wax forms, so i decided to put on of the design in rhino. This allowed me to test shapes without wasting materials. This also allowed me to work out dimensions.