Pressure Testing Your Watch
A popular watch repair we are asked to perform at Timepiece Watch Repairs in Wigan is a watch 'pressure' test. A pressure test will confirm that your watch is still water resistant to the manufacturers specification once a repair has been carried out. This is normally required after a new battery is fitted or occasionally when other case repairs are carried out such as a replacement glass, pusher or winder. Each of these watch components play a part in your wristwatch's resistancy to water.
A sealed watch (splash-resistant or higher) was originally manufactured with a seal at each entry point of the watch case. These entry points include:
- Glass/Crystal
- Case back
- Buttons & Pushers
Some watches may have other entry points however the ones listed are the most common. Over time, the seals on these entry points can begin to wear out. If one of these seals is removed in order to gain entry to the case or to replace a damaged part, the watch will no longer be guaranteed water resistant and a pressure test will be necessary. A 'reseal' and pressure test can be carried out for you at our branch of Timepiece Watch Repairs in Wigan after a battery replacement or other watch repair.
If the seals are worn out, they can normally be replaced. Over time, rubber seals will dry out and start to crack, especially if the watch is used in salty or chlorinated water. If the seals are in good condition, applying the correct greases will maintain their good condition at each reseal. Once your timepiece has been correctly sealed, it is time for a pressure test. This test can be done in a variety of ways. The most common of these are either an air test or a water test.
Water Testing
A water test involves placing your watch in a pocket of air over water inside a water testing tank. The air pressure inside the tank is then increased. After a minute the watch is submerged in the water and the air pressure is then slowly released. As with an air test, any air that had leaked into the watch before it was submerged will try to equalise with the lower pressure outside the watch. If this happens, it is clearly visible in the form of a constant stream of bubbles coming from the position of the leak. It is important to note that air is coming out and not water going in. If bubbling doesn't occur, then the watch is air tight. Unlike an air test, the air pressure can be altered to test for different water pressures e.g. 10 metres, 50 metres etc. This type of test takes a little longer than an air test but is far more accurate and allows a technician to spot the exact position of a leak making any required repairs quicker and more cost effective.
At Timepiece Watch Repairs in Wigan we use a water tester and our technicians can usually install a new high quality battery and pressure test your watch to its original specification within half an hour. At Timepiece Watch Repairs in Wigan we only use high quality silver oxide batteries. Poor quality batteries can leak, sometimes damaging your watch irreparably. Alkaline batteries, although similar in appearance, don't usually last much more than a few months and yet again there's a high risk of these batteries leaking when used in a watch. Our staff are well trained and experienced and will replace your watch battery correctly and professionally without damaging the case back, movement or battery clamp.
Air Testing
To carry out an air test (also known as a vacuum test), your watch case is placed, case back down, on a podium inside an air testing machine with a fine 'needle' resting on the centre of the watch glass. Air is removed from inside the machine creating an air vacuum around your watch. The air pressure inside your watch will attempt to equalise with the air pressure outside the watch making the glass of your watch bend very slightly outwards. This convex bend is measured by the needle resting on the glass. Over the next minute, this measurement needs to be checked for changes. If the measurement has altered, then the pressure has equalised (if only slightly) signifying an air leak. If it hasn't changed, the watch is most likely air tight.
The advantage of this kind of test is that it is quick and uses no water. The disadvantage is that watches with a thick glass can fail to bend, so no variation will be observed. If your glass is curved (or domed) then the needle can move giving an inaccurate reading. Also, no specific pressure is defined, only that the watch is air tight to a degree.
We carry out many other watch repairs including servicing to the majority of watches. Please call in to your local Timepiece store and speak to one of our helpful technicians for advice on your watch repair. We also stock a large range of quality watches in store.
