Within this article, I explain the process and the techniques used for creating my Zenith 1939 tabletop model. The project took 5 weeks as part of my Final Major Project at The Arts University College of Bournemouth. Further images can be found within my Portfolio.
For part of my Final Major Project at The Arts University College of Bournemouth, I decided to make a 1:1 product model of a 1939 Zentih tabletop radio. I chose to make this as I had around 5 weeks remaining and wanted to make something, which I could use a variety of materials, techniques and processes on. The idea was to improve my knowledge of these aspects and I chose this radio, mainly because I just thought it looked cool. The Art Deco style of the radio helps bring the basic box-shape radio to life, as does the bakelite materials combined with the wood grain and dials.
I actually found several versions of the radio as you can see in the images below. The main differences are the speaker surround and the centre-piece, which use different materials; as does the button panel. My idea was to use elements from both radios to create my own.
I gathered a range of images to get going and started by creating an MDF shell to create the main section of the radio. As I needed to chamfer the edges, I used 22mm MDF. Using the mill, I bored out a hole in the centre, and I cut a rectangle where the speaker section would sit. All sides were then assembled together.
Once the main shell was assembled, I then chamfered the edges with a sander and hand finished them to get the desired finish. I then applied a styrene sheet to the bottom to which I would spray bakelite colour.
For the speaker section, I decided to lasercut it which meant cutting several components and assembling it together. This was fairly quick to construct. I drew the parts out in Rhino as it offered accurate 2d lines. I then exported the lines into Illustrator which meant I could prepare the file for lasercutting. Once cut, I assembled the components together.
With the main shell constructed, I then made the side panels. I used Chemiwood for this as I wanted a high and crisp finish which would not have been achieved as well if I had used MDF. As these side panels also needed chamfering, I handsanded the edges using the main MDF shell as a guide.
With the side panels shaped and the speaker section assembled, I then prepared them to spray brown, which would represent the bakelite parts of the radio. The MDF speaker section was sand sealed, the styrene was keyed and sprayed with plastic primer. The chemiwood required no treatment before spraying. All parts were primed with grey cellulose paint. This was to pick up any irregular parts and uneven surfaces. All necessary parts were then sanded back and any extreme irregularities were filled and sanded. Everything was primed for a second time. Once I was happy with the finish, I then sprayed the components with brown cellulose paint with a high finish to achieve the bakelite material. I feel the spray finish was of a high standard.
Now that the side panels were sprayed, I the started to clad the main MDF shell with veneer. This was a little problematic as the chamfered edges needed the veneer to bend against the grain. I used iron on glue film which also provided enough heat for the veneer to bend against the grain. I applied the veneer to both the main shell and the speaker part. The iron on glue wasn't the most effective as I had to apply other adhesive to strentghten in various parts but it was suitable due to the heat and bending the veneer. The veneer used was Crown Cut Sapele.
For the strip on the right, I used zebrano veneer. The problem was that the grain had to lay across the length and this was difficult to find. I ended up joining 5 small strips together which worked well as the join were made invisible. I also attached some brass wire mesh to the back of the speaker at this point.
Both the Crown Cut Sapele and Zebrano veneers were later finished with a medium wood dye to match the reference photos of the original radio. I then applied a satin varnish to both of the veneers for the end result.
For the main dials, I modelled one in Rhino, and then 3d printed it using a powder print. The ABS print did not turn out as well and required some cleaning up. The powder print was good enough to use straight away so I strengthened it with superglue.
For the other buttons, I turned them from blocks of chemiwood on the lathe. I made one of each button and dial so I could mould and cast them.
For the buttons and dials, I made simple silicone block moulds using the 3d print dial and turned chemiwood as masters. Once cured, I then cast them all in Polyurethane resin (Fast Cast).
For the button panel, I made a quick sketch model using card and the resin casts of the buttons I made. This gave me an idea of how it would all be assembled. I made the final button panel from acrylic, which I cut grooves out using the mill. This provided the correct depth and accurate lines. With this acrylic panel, I then made a silicone block mould and cast it in polyuerthane resin like I did with the buttons. I added brass metal powders to the resin to give the brass effect. I then later attached the button panel to the main part of the radio.
For the centre piece, I used an MDF template and used a router to achieve the curve. Chemiwood would have been a better material to use but I already had the MDF template and I didn't have enough time to re-cut it. Although MDF is often not crisp, I managed to achieve a perfect finish by sanding, priming, and filling several times. I used milliput to sculpt the three rings around the top of the centre piece. Once the milliput had set, I then sprayed the whole centre piece the same brown as the side panels.
The glass dome was achieved using a vacuum former, a former and PTEG plastic. For the graphics, because there was no picture at the correct size, I drew everything from scratch using Illustrator and then Photoshop. I made the ticker using a lasercutter from drawings I made in Rhino. I then made a silicone block mould of the acrylic parts and then cast in polyuerathane resin and metal powders.
The centre piece assembled together can be seen in the images below.
Here are images of the final radio.