Care of underwater detectors
Many people have bought underwater detectors to hunt the beaches, lakes and rivers for treasure but many are still unaware of how to take care of their detector and protect it. For the salt water users the seawater will cause corrosion quickly and set up salt deposits to jam shaft connections. Detectors that are used in salt water should be rinsed off with a hose when it is brought back home.
Damage usually occurs by hunters who get lazy and do not give proper attention to the seals on the detector. Some buy them second hand without benefit of information on the detector or even the correct kind of sealant to prevent leakage into the unit.
In the early sixties I was an active scuba diver and had a diving shop where I had my first experience with the seals. I bought a terribly expensive underwater camera which had an “O” ring but did not come with any sealant. In the early sixties the silicone sealant was unheard of at least for me so I took a good look at the neoprene “O” ring and decided that it needed something to lubricate it and provide a good seal so that I wouldn’t get a leak in my new expensive camera. I looked around at my options and chose Vaseline jelly. It looked good to me so I lubricated the “O” ring with it and closed the housing up with the camera and film in it and took it to the salt water. Shortly after I entered the water with it I had one of the worst feelings that I have ever had! The salt water was rising up about half-way on the camera inside the casing. The seal had failed although I tightened it very good and could see that it was flattened out indicating it should prevent a leak.
Well folks, we all learn from our hard lessons, and that is one of the hard truths of life I guess. I also ran an electronics shop aside from the dive shop and so when the factory sent me back a refurbished or replaced camera I felt somewhat guilty because it was my duty to see that it did not leak! Nevertheless, I was glad to see it back looking dry again. Now I reflect on that because I probably should not have sent it back. It was my failure and I should have had to purchase a new one and not the factory.
Having a good camera again I also noticed at the wholesale electronics supply that they had a new silicone lubricant that I could use to coat the contacts in switches because the were silver and as they turned black they failed as contacts. The silicone worked wonders on the contacts and looked like it might fit the bill for the camera.
This time I got a little smarter. I took the camera out of the case and lubricated the “O” ring with the heavy silicone lubricant. The underwater case did not even leak a drop! ha! I finally found the right thing to use on the seal and sure enough I took it miles offshore in the ocean to a deep bottom and it never leaked. Feeling victorious about this I undertook to build underwater movie camera housings and using this method and success! I instinctively knew what to do when I got my first underwater detector some time ago. I have never had an underwater detector leak on me.
It should not be the fault of the manufacturer if you let your unit leak so take time and clean for your unit carefully. Every time you store your unit remove the batteries and clean the “O” ring seal of sand and salt buildup. I spend some time doing a good job because only “one” grain of sand can cause you to loose your detector. I use a lot of soft tissues and sometimes a little alcohol to clean off all the lubricant. After storage or after installing the new set of batteries then I clean my hands good and take a little bit of silicone lube and rub onto the “O” ring seal to coat it lightly all over. Next I apply a little silicone coating to both the clean faces of the seal plates. Then I carefully fit the unit together and tighten the unit until the seal is flattened fairly good. Take care not to apply too much pressure as you can damage the unit.
Some detectors have separate battery compartments from the electronics and that is a wise thing to do. However the Fisher CZ20 uses a different kind of gasket than the traditional “O” ring and I believe they should change it to an “O” ring as I have heard of several folks getting water in the battery compartment. I clean the seal and faces well and then apply a coat of silicone to all surfaces and tighten the screws onto the compartment carefully to apply even pressure to each side and also apply a good pressure to the seal.
When you purchase your underwater detector it may come with a tiny tube of silicone lube however it won’t last long if you hunt as often as I do. Some companies are very proud of their tiny tubes of lube and want very large prices for the stuff. I guess because of my experience with the problem I sought out a more price effective answer to the problem. I looked around for a while and finally found it at a local pool supply very cheaply. Beware that they also have many other kinds of silicone lube but only one kind that is very thick and white. They use it to seal the “O”rings in the chlorinaters on the pool pumps. I tested this for my own use down to a depth of five feet deep and it passed the test just fine. You may consider this alternative and if you choose to use it you may invalidate your warranty and you must use this at your own risk!. The name of the silicone that I bought was “Magic lube” number 650 in a red, one ounce plastic tub.
It is summer now and the car gets hot enough to fry eggs. You should know that if you put your sealed underwater detector in such a hot place and leave it that the internal pressure can build up and blow the seal and perhaps damage key components like capacitors or chips. If you take good care of your unit it should last you a long time and be a productive purchase but just take it for granted and you will likely loose it.