Pressure Testing Your Watch
All sealed watches are constructed with seals of various types at each entry point of the watch case. Water entry points include the watch glass, case back and the buttons and pushers. At Timepiece Watch Repairs in Oldham we regularly carry out watch 'pressure' testing. This is normally required when a new battery is installed or if other repairs are carried out on the case such as a new glass, pusher or winder. Some watches may also have other entry points. All these parts play an important part in your wristwatch's resistancy to water. If your watch passes its pressure test, your watch is guaranteed water resistant to it's original depth after a repair has been carried out. Over time the seals on your watch can begin to wear. Whenever a sealed part is removed to gain access to the case or to replace a damaged component, the seal will no longer be guaranteed water resistant and a pressure test is necessary. A reseal and pressure test can be carried out for you by Timepiece Watch Repairs in Oldham after your battery is replaced or if any other repair is carried out to the case. If the watch seals are worn, they will require replacing. Rubber seals dry out and begin to crack over time, particularly if the watch is worn in salty or chlorinated water. If the seals are in good condition, applying the correct greases maintains their condition.
Once your watch has been properly sealed, it is time for the watch to be pressure tested. Pressure testing can be carried out in a number of ways. The usual methods are air testing and water testing. With air testing, also known as a vacuum testing, the watch case is placed with it's case back upon a podium inside an air testing machine with a needle resting on the middle of the watch glass. A pump then sucks the air from inside the machine making an air vacuum around your watch. The air pressure within your watch will then try to equalise with the pressure outside the watch. This will cause the glass of your watch to bend a tiny amount outwards. The bend in the glass is then measured by the resting needle. After a minute, this measurement needs to be checked to see if it has changed. If the measurement has changed, then the air pressure has escaped from the watch signifying a leak. If the measurement hasn't altered, the watch is probably air tight with no leak. The benefit of this type of test is that it is reasonably quick and uses no water. The problem with this type of test is that a watch with a thick glass can sometimes fail to bend and no variation will be measured. Also, if the watch glass is domed then the needle will sometimes move meaning that the reading is inaccurate. Another problem with an air test is that no pressure is defined, meaning only that the watch is air or water tight to a certain degree but with no specific depth measurement.
A water test involves putting the watch in a pocket of air above some water inside a water testing tank. The air pressure in the water testing tank is then slowly increased. After about a minute, the watch is submerged in the water. Then, the air pressure is slowly released. Just as with an air test, any air that has leaked into the watch case before submersion will now attempt to equalise with the lower pressure outside the watch. If there is a leak, it is seen in the form of a persistent stream of small bubbles coming from the position of the leak. Note that air is coming out, not water going in. If bubbling doesn't occur, then the watch is correctly sealed. The air pressure can be adjusted to test for different strengths of sealing e.g. 50 metres, 100 metres etc.; an option not available with an air test. A water test takes slightly longer than an air test but is far more accurate than an air test and allows location of the exact position of any leak. This can make any repairs quicker and probably more cost effective.
Our technicians at Timepiece Watch Repairs in Oldham use water testers and can frequently replace your battery and pressure test your watch to the original specification inside half an hour. At Timepiece Watch Repairs in Oldham we use high quality silver oxide batteries from well known manufacturers. Poor quality batteries frequently leak, possibly damaging your watch irreparably. Alkaline batteries, although similar in appearance, normally only last a few months and again, there is a risk of leakage when used in your watch. Our well trained and experienced staff can replace your battery correctly and professionally without damaging the case back, battery clamp or movement.
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 and on our website at www.watchesbytimepiece.com.