For my final product I wanted to design and make a tea strainer. Seeking inspiration from tea strainer designs online I quickly developed a 3D CAD model of my chosen design (follow links below for PDFs).
I took these drawings to the jewellery department top ask about the optimum process to achieve the desired result. I was informant that the work would take roughly one and a half weeks to complete if I was to make it myself with supervision. I was also offered to commission one of the in-house designers to craft the piece; this option would take around 3 days whenever the designer was available. I didn’t have the ability to commit a week and a half to the creation of this piece and so I needed to think of some other method. I decide to change my angle slightly and make a bamboo tea strainer, using my wood crafting skills.
Using the bamboo method I would have the ability to create the bulk of the piece, however I would still need a mesh or holed part to catch the tea. I decide that I would like to try and make this part out of metal. Doing this would take roughly half a day due to the relative simplicity of the part. Below I will describe the process I underwent to produce the final parts seen below.
First things first, I needed some metal. I decide to use copper because it is relatively easy to work and its colour is in keeping with my design language. The copper was cut into manageable squares and the circles scratched on. Next the holes were neatly marked, so as to know where to drill them out. After the holes were drilled out, using a small pillar drill, we decided how to produce the depth in the parts. It was decide that the oval shape would be fly-pressed and the two circular ones would be hammered out.
Before the fly-press could be used we needed to soften the metal, this Is achieved by intruding a hot flame to the metal in the form of a blow torch (see below)
After the heating the metal is sharply cooled in the sink.
The metal is finally placed in the pickeler to remove the black sooty residue left by the flame.
Once all the heat treating had been completed we moved into the fly-press. The fly-press uses a pressured arm to physically push a shape out of the metal. This firstly requires the user to create a mould. I created three mould (26x26mm, 28x28mm and 27x30mm) I did this with the intention of fly-pressing all three is the pieces. As it turns out the circular parts can be hammered instead, a much easier process with the ability to make the depth larger. The three moulds were laser cut out of 5 mm acrylic, a material that is strong enough to withstand the pressures of the fly-press. The fly-press process involves placing your small sheet of metal over the mould and then place a lump of blue tack upon it. The blue tack will be pushed down into the cavity allowing for a uniform depth. Once the fly-press process had been completed all three sheets of copper (two of which have not yet been formed) must be cut out using a very fine jewellery saw.
After the three circles had been cut out they had to be filed down to the exact shape that was desired. After this process was completed I was left with one piece almost completed and two flat parts still needing hammered out. The hammering process involves using a metal block with cavities. Once I had determined what depth I wanted I simply placed the circular copper piece into the cavity and bashed it with a hammer that equalled the shape of the cavity. This resulted in two piece that were of uniform size.
Now that all three pieces had been shaped it was time to polish them. I use the polishing machine to get the texture and finish that I desired. After this I was left with three well finished copper parts. I intend to using there copper parts within my tea strained design, I will post my completed iterations soon.