Time Menders has been awarded the contract to restore the tower clock at the V&A waterfront. This amazing clock has a completely mechanical mechanism and is one of the most finest examples of a well made mechanism that I have encountererd in my career as a clock maker. The clock was made by http://www.jamesritchieclockmakers.com/ . I will be documenting all the work and will post pictures for general interest.
Here is the breakdown of the work done on the clock;
Firstly all the paint was removed from every part of the clock, I soon realized that the gears were cast and very roughly finished so I made the decision to clean them up and expose the base metal (phosphor bronze). This was the most time consuming of all the work because each gear had to be filed, sanded and polished. In some of the gears I had to remove quite a lot of pit marks. Here is a picture of what the gears originally looked like.
Once this had been cleaned up it was then the task of finding and fixing faults. The first main problem was the main gear on the going side (the side that ticks and keeps time). At some stage something very heavy was dropped onto the gear ( I assume this, because it was so badly bent and this would require a very hard force). The gear was so badly damaged it was almost 1cm out and the spoke was bent. The problem was fixed by firstly cutting through the bent spoke, I made a template using the good side of the gear so I had some form of reference, I then welded two big pieces of steel onto a table and then used a large clamp against the steel to pull the gear back into shape, a wedge was then fitted into the spoke to keep it in shape. Here are a few pictures of the process.
The next step was the steel, after many years all of the steel bolts, nuts and screws were starting to rust or were badly rusted already. Every piece was polished and then blued, steel bluing is done with heat and has two functions, firstly the steel is more attractive and secondly it is much more protected from rust. The process is to bed the steel into brass filings (this helps to distribute heat evenly, the steel is then heated till it reaches the desired temperature. The temperature is not measured but you can tell because the metal changes colour, you then just heat it until you get it to a nice blue, then cool it in oil, this is also part of rust prevention. When metal gets hot it expands, under a microscope you would see microscopic pores in the metal getting bigger. When the metal is dropped into oil the oil penetrates these holes and helps to prevent rust. Here are some pictures of this being done.
There were one or two small mechanical problems but this was more replacing bent pinions and burnishing bushes.
The next stage was the painting, the entire base and all main castings were stripped and resprayed. All the brass was then polished and sprayed with industrial 2k lacquer to prevent tarnish. The pendulum and weights were also repainted so every part was refinished. All parts were first coated with a red oxide primer this prevents rust and primes the base metal for spraying, the next coat was 2k primer and then 2k green.
At this stage the clock was assembled one gear at a time each one was checked and tested to make sure it was running correctly. It was then assembled, the timing was set and all bushings were lubricated with graphite grease, I then set the clock up in my workshop to test run and make sure everything was working correctly but……. no luck! The escape wheel (wheel that makes the clock tick tock) was damaged badly, many teeth were slightly short and one was so bad that it needed to be replaced, a new piece was soldered in and filed to shape. The wheel was then put into a lathe and all the teeth were cut to the same length. After this process I had to adjust the pallet so that is worked correctly with the shorter teeth. Here is the escape wheel repair process.
In the final step of the process I test run the clock before delivery, it had been running perfectly for three days at that point. I was very pleased with the outcome and honoured to have been able to work on a piece of Cape Town’s history.
Here is a photo and video taken after the restoration.
Here is a short video of the clock being test run.