14 Feb 2011, 18:20
The Making Of; the Superlative Oil filled Casio F-91W DeepSea
The humble yet iconic Casio F-91W is a pretty good watch and costing only some 12 euros it is just about impossible to beat its value for money. Small wonder it is the world´s most worn wristwatch by far.
It does have two weaker points:
* the strap, which is prone to break over tome
* the water resistance, which is only shower proof
The first issue is easily enough solved using G-shock strap adaptors so it can be used on a ´Nato´ type woven strap.This way mounted on the strap the head does not get stressed when there is a pull on the strap and the strap itself is unbreakable.
The water resistance is a more challenging issue. There is however a solution which is as effective as simple to apply; fill the head with liquid to start with.
Since a liquid cannot be compressed simply filling the watch with liquid without any bubbles would fill it at zero pressure meaning the liquid will stay in as the seals can take thát.
Since a liquid cannot be compressed simply filling the watch with liquid would make the watch resistant to any further liquid ingress to whatever depth since it already ís 100% full.
Ok. So what liquid to use?
Oil is the simplest since it does not conduct low voltage currents and is water repellant.
Vegetable oil would be compatible with rubber and plastics.
Since the F-91W is thé campo watch worn by just about áll workers in the olive oil industry and extra virgin olive oil is the superlative vegetable oil, the choice was made; extra virgin olive oil.
A first test revealed that the quartz module would submersed in oil indeed keep funcioning as Casio intended.
It also proved to be a bit of a pain to fill it for 100%;.
The idea however proved sound as lowering into a two metres deep tank gave no problems.
Time to do it properly:
Step 1. prepare everything needed
Step 2. once prepared with a bocadillo seranito and a nice glass of Tempranillo, fill the bowl and remove the case back
Step 3. lower the head into the oil, with one side down and sssssslooooooowly inmersing it to give all the air time to rise and exit
Step 4. lower the case back, inner side up and while inmersed turn it round and put it on the back of the head, taking care not to trap any air
Step 5. put the screws back while retaining the oil
Step 6. check
Step 7. clean the watch and enjoy the Superlative oil filled F-91W
Using this olive oil has the additional advantage that the greenish colour cléarly shows that the watch is filled with it.
I forgot to mention:
Because there is now no air inside, there is no refraction on the inside of the ´crystal´, so the legibility under the slightest angle has been noticeably improved. It is like the inside has the ultimate AR coating.
Petrus
The humble yet iconic Casio F-91W is a pretty good watch and costing only some 12 euros it is just about impossible to beat its value for money. Small wonder it is the world´s most worn wristwatch by far.
It does have two weaker points:
* the strap, which is prone to break over tome
* the water resistance, which is only shower proof
The first issue is easily enough solved using G-shock strap adaptors so it can be used on a ´Nato´ type woven strap.This way mounted on the strap the head does not get stressed when there is a pull on the strap and the strap itself is unbreakable.
The water resistance is a more challenging issue. There is however a solution which is as effective as simple to apply; fill the head with liquid to start with.
Since a liquid cannot be compressed simply filling the watch with liquid without any bubbles would fill it at zero pressure meaning the liquid will stay in as the seals can take thát.
Since a liquid cannot be compressed simply filling the watch with liquid would make the watch resistant to any further liquid ingress to whatever depth since it already ís 100% full.
Ok. So what liquid to use?
Oil is the simplest since it does not conduct low voltage currents and is water repellant.
Vegetable oil would be compatible with rubber and plastics.
Since the F-91W is thé campo watch worn by just about áll workers in the olive oil industry and extra virgin olive oil is the superlative vegetable oil, the choice was made; extra virgin olive oil.
A first test revealed that the quartz module would submersed in oil indeed keep funcioning as Casio intended.
It also proved to be a bit of a pain to fill it for 100%;.
The idea however proved sound as lowering into a two metres deep tank gave no problems.
Time to do it properly:
Step 1. prepare everything needed
Step 2. once prepared with a bocadillo seranito and a nice glass of Tempranillo, fill the bowl and remove the case back
Step 3. lower the head into the oil, with one side down and sssssslooooooowly inmersing it to give all the air time to rise and exit
Step 4. lower the case back, inner side up and while inmersed turn it round and put it on the back of the head, taking care not to trap any air
Step 5. put the screws back while retaining the oil
Step 6. check
Step 7. clean the watch and enjoy the Superlative oil filled F-91W
Using this olive oil has the additional advantage that the greenish colour cléarly shows that the watch is filled with it.
I forgot to mention:
Because there is now no air inside, there is no refraction on the inside of the ´crystal´, so the legibility under the slightest angle has been noticeably improved. It is like the inside has the ultimate AR coating.
Petrus
´Design oder nicht sein´
