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Maintenance
Caring for the watermaker
Periodically check that the 6 nuts and bolts of the clamping fittings are tight on each end of the tow tube
The life of a Waterlog can be considered as the life of the unit itself and the life of the membrane element.
The Waterlog is built of marine grade 316 stainless steel and should last a lifetime. If the owner so wishes, he or she may replace any of the individual internal components, i.e., Bearing block or the pump, which is a simple job. If it is desired to replace the bearing block or pump, remove the screws holding these in the body. There are three of them for each of the components (block and pump). Slide out the parts as required and reassemble observing the procedure as set out below for replacing the membrane element.
The membrane element can run continually for 5 to 7 years non stop under ideal bench test conditions. However, the oceans of the world are not ideal conditions. In general, a membrane in a cruising application will probably last between two and five years if properly cared for. Much depends on how clean the input feed water is over its lifetime. A membrane may be replaced by removal of the three screws around the nose block, pulling out the nose block and then pulling out the membrane element.
To replace the membrane element, open the sealed poly pack containing the new element. You will note that the element has a short tube or nose at each end. One is white, the other is a little larger in diameter and is black. Lubricate each nose each end with a little smear of edible glycerin or washing up liquid (DO NOT USE ANY TYPE OF OIL - EDIBLE OR OTHERWISE). Firmly slide the new membrane element into the body of the unit with the BLACK NOSE FIRST. Likewise, lubricate the "O" ring on the nose block and insert it into the body. Care must be taken not to damage the "O" ring when inserting it.
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Things to note:
If your unit is fitted with mesh filtration, check the filter every time before use to ensure it is clean. To do this, with the impellor removed, rotate the ring fully (about one eight of a turn) on the impellor end of the unit and pull it off. (It is a self locking arrangement to enable quick access to the filter by hand without any tools). The outer stainless filter cover tube can now be slid off the unit, revealing the mesh filter. Slide off the mesh filter to be washed out if necessary. Note that the filter is actually three layers of stainless steel mesh, the center layer (which is not visible) is very fine so take care when handling and cleaning not to puncture with a sharp object. Use running water, detergent (washing up liquid) and a soft brush to clean.
To replace the filter, carefully slide it onto the unit, easing it over the screw heads on the body until it sits on the lip of the black ring surrounding the main body. You may need to turn it a little ("wiggle" it) to get it properly seated in its position. Slide on the stainless steel filter cover tube. This is a little loose as the tiny gap around the edge and end is the first stage of filtration. Replace the filter retaining ring by rotating it until it moves forward and then twist it to lock. Never use a watermaker with a dirty, occluded or punctured filter. This could shorten the life of the unit or cause damage. Checking the filter only takes a few seconds before using.
Treating the unit for storage
It is essential that the blanking plug is kept inserted in the center hole of the nose block at all times and is only removed when in use, i.e., while the hydroplane / tow tube is fitted. If the watermaker is not going to be used for some time, such as many days or weeks, particularly in hot weather, it will be desirable to treat the unit with biocide. This is to inhibit the development of bacteria inside the unit leading to "last years water tank taste". Although not necessarily a threat to health,
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it is nonetheless unacceptable. Waterlog produce small jars of biocide suitable for their own membranes. If you do not have a hygiene kit, a solution of food grade sodium metabisulfite in a ratio of 1.5 percent in water is appropriate.
Quick biocide treatment for short term storage. Take the recirculation tube (the short piece of small black tubing with a swivel elbow fitting on each end) and very carefully screw the elbows into the holes on the side of both the filter retaining ring, and the nose block (which is attached to the hydroplane / tow tube assembly). DO NOT use any spanner or other tool - screw in only finger tight. Take care to ensure that when inserting the elbows that you do not "cross thread" them. If you feel any resistance at all, lift away the fitting and gently try again until they screw in smoothly.
Rotate the filter retaining ring and pull it forward until it reaches the impellor blades. Look around the circumference of the exposed part of the bearing block and you will see a large hole. With this hole facing upwards, carefully pour in the powder contents of a Green spot jar, or as directed by the brand label on the suppliers packaging. The volume to be treated is 1.0 liter approximately.
The watermaker now has the appearance of a silver tube with a very small black flexible tube running from one end to the other. Replace the filter retaining ring and twist to lock in the usual way. With the vessel stopped, invert the unit so it is hanging by the tow tube with the impellor facing the water. (some water will leak out - this is normal). Without delay lower the unit into the water. Bring the boat up to a speed of about 4 knots. After some 30 seconds (do not exceed 60 seconds) at that speed, stop the vessel and retrieve the unit aboard.
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Remove the recirculation tube, impellor and tow tube and insert the blanking plug. The unit can now be stowed.
Biocide treatment for longer term storage. Wait 24 hours since last use. Remove the nose block (see below) and empty the unit of water. Open a jar of biocide (green spot), dissolve in a liter of clean water and pour into the unit. Replace the nose block (see below). The unit may now be stowed away.
Pickling. If best maintenance and maximum life of the membrane is to be achieved, it must occasionally be treated with chemicals which remove the accumulated deposits from the surface of the membrane. (See page 18). Waterlog produce special formulations in powder form to do this and are available as a spare part kit. ("Hygiene kit" - part No. 17). If you do not have a Waterlog hygiene kit, there are numerous preparations available from boat equipment suppliers. In general, the procedure may be the same as for using biocide, however, it is better to remove the element from the unit by releasing the three screws at the tow tube end and remove the nose block. Before removing these screws wait 24 hours since last used to allow any residual pressure inside the unit to dissipate. The membrane element may then be withdrawn / pulled out of the body. It may then be immersed in the pickling solution in any appropriate container available. If using Waterlog pickling compounds, this may be done without removing the membrane element. Always take great care when handling any solutions and immediately rinse any area of skin or surfaces which may come into contact with the solution.
As the cost of replacement Waterlog membranes is modest, many do not bother to "pickle" their membrane (membrane life may be substantially reduced however) and carry a spare element should it be needed.
Spare parts
Spare parts and technical advice is available from waterlogenquiry@aol.com