**George is currently on a mooring ball in Hatchet Bay, Eleuthera, boatsitting while the owners are away on business. In between his long walks on the beach, studying for his paragliding certification, and missing me, he rebuilt a 10 yo Spectra Watermaker, because he IS That Boat Guy. And in his own words, here is how he did it:
When I first met Nick and his boat Summer Wind, I was complimentary about almost everything about the boat and the way it was fitted out for cruising. I asked if there was a watermaker and when Nick told me there was a Spectra onboard, I tried very hard to follow Thumper’s Father’s admonishment and “just say nothing at all.” Unfortunately I think my facial expression gave away the game. Not only was this a Spectra, but it was more than 10 years old, had been pickled (stored with preservatives) at least 4 years prior, and this was on the word of the broker who frankly could not have known first hand. The prognosis was not good and having been prodded for my opinion, I said so. I asked Nick to go ahead and order a membrane because I knew we would at the least need that, and it’s just a good idea to start out with a fresh one anyway.
So we tabled it. And there was always something more pressing to work on. Just little things but still. Until one fine day here in the Bahamas we could wait no longer. There simply was not a good free supply of water to fill the tanks anymore, and we decided to give the thing a try. It started, and then it stopped and declared (by way of its little display screen) that the salinity level was too high. This was in accordance with my expectations as I never imagined for a moment that the membrane (the fine high pressure filter) could have survived a storage stint like that. Nick had contacted Spectra in the meantime and in his usual first class way, told them to put together a kit with everything they thought he might need to recommission the watermaker. That’s just Nick. If I tell him I need an egg he brings me a dozen and the hen that laid them. They had put together a humdinger of a kit with everything except… a new membrane.
Meanwhile, the “experts” were telling me that it was probably not the membrane but the salinity sensor. OK, there was a new salinity sensor in the kit and it only took about an hour and a half to swap it out with the old one buried in the guts of the watermaker installed deep in the guts of the boat. Once again, the little display announced… salinity too high.
I could hear the Clark pump cycling, it was producing plenty of brine but I had my suspicions. The thing is tremendously complex and with a number of failure points that could cause our symptoms I figured the simplest explanation was that it had indeed failed. But the “experts” were telling us that the Clark pumps never fail. Alright, I decided to bypass everything and run it in manual mode. It produced zero product.
The experts (and the troubleshooting flow charts) then seemed to focus on the primary pump. And there in the humdinger kit was a new pump head for that pump. So I rebuilt the primary pump complete with broken bolts that had to be carefully drilled out. No change in anything.
So that settled that. We had a crew member flying home and then rejoining the boat after a few weeks, so we went ahead and ordered a membrane, which she could bring with her. And we ordered it from my buddy John at American R/O at a great discount to boot! I figured if the Clark pumps never fail, and I can hear it cycling, and we are still getting zero product, then this membrane must be toast.
So when the membrane arrived, I installed it. The stench from inside that pressure vessel when I pulled the old membrane was a bittersweet vindication. This thing had not been pickled.
Salinity too high. No product. So I wrote directly to Spectra, explaining everything I’d done to this point and expressing my suspicions about the Clark pump (which never fails). And although these pumps never fail, there was a giant assortment of o-rings in the humdinger parts kit that would provide for a complete overhaul of the pump. In a couple of days I got a reply, not from some technician which is what I expected, but from the GM of Spectra. He gave me a PDF dump of everything a handy tech would need to rebuild a Clark Pump and/or troubleshoot the remainder of the electronic control systems. I have to tip my hat to Spectra on this point. I may disagree with design philosophy, and that’s one thing, and frankly it’s just one guys opinion, but in the customer service department they are doing a great job. I explained who I was and what I needed and they gave me the help I was looking for. I decided it was best to wait until I was alone on the boat to tackle this. I read everything I was given forward and backward. I lined up the tools I would need and decided what I’d do to improvise around not having some of them. I arranged all those o-rings and other parts in a logical array.
If you have ever read the novel, “Zen and the Art of Motorcycle Maintenance”, then you know that the author is a very meticulous and hyper-organized mechanic. He would disassemble a machine piece by piece and spread his work out with all parts arranged in order of removal so as to have the best chance of getting everything back together again in the proper sequence. I rarely work that way. My process is more… chaotic. This time was an exception for me. It was just too complex a device with too many chances to lose some little critical part or get everything back together and discover some little seat or o-ring or poppet leftover.
And so began the saga of the rebuilding of the Clark pump that never fails. In the process, I found some trash in one of those many little failure points I was talking about earlier. Ah hah! It was a piece of plastic wrap about the size of a dime in one of four check valves. That’s what stopped this Seven Thousand Dollar watermaker from working – a piece of plastic wrap the size of a dime.
I reinstalled the newly rebuilt Clark pump into the watermaker. I reinstalled the watermaker into the boat. I started it up on manual and lo and behold! Product! Full output on this device is a tiny trickle of fresh water and that’s precisely what it was giving. And after giving it enough time to clear the storage chemicals, I tasted it (personal salinity detector) and declared it good!
So the next thing was the question of whether or not it would run on automatic. I gave that a try and it ran for a bit, then quit and restarted, then quit and restarted… 4 times… and then the little display declared… System Stalled. What? The system was not stalled, it was pumping away just fine. I switched back to manual mode and sure enough… cool clear clean fresh water.
So I went back to school. Apparently on the older units the the automatic system relies on a thingy called a Stroke Sensor to determine if the Clark pump is doing its thing. They put a magnet at one end of one of the pistons and every time it gets near the end of the cylinder it triggers a little magnetic reed switch and returns five volts back to the “brain” and illuminates a little LED light. The next stroke it does not return five volts and it turns off the little LED light and so on and so forth. If this sounds like a really complicated and readily fallible way to accomplish the task of determining if the watermaker is in fact making water, then you would be right. There was no light illuminating at any time. So I found a troubleshooting guide for that thing, went probing around with a volt meter in the electronic guts, and determined that it had indeed failed. I’m counting this as Clark pump failure number two by the way, the pump that never fails.
And so I took a little trip I’ve been taking since about age five. I decided that since it had failed anyway there was no harm in taking it apart to see how it ticks. At age five, this was quite literal as it was a dead alarm clock I’d been given. I fixed that alarm clock, too. I discovered a wire that went nowhere. As careful as I was in de-potting (removing the sealant encapsulating the little circuit board and connections) I couldn’t tell if the loose wire I discovered was the problem, or something I had accidentally done myself. One way to find out. I cleared away the remaining potting painstakingly in order to see how the components were arranged and where my wire must have been attached. I then re-soldered it. Then I re-potted everything and went for a long walk on the beach. When I got back the potting was dry, and I reinstalled the Stroke Sensor to the Clark pump and baddabing baddaboom! It’s working in fully automatic mode. Now all that anyone need do is push a button to make water. If the filters need changing, the machine will tell the human what to do. When it fails again of course it will display some little cryptic message on its tiny little display and someone will have to sort it out. Hopefully not me.
1. The Spectra Watermaker in its hole:
3. The “smoking gun.” A dime sized piece of plastic wrap that probably originally came as covering for one of the pre-filters:
4. The Stroke Sensor. Hey, I just wanted to see what was inside and you never know, I might just be able to fix it…:
5. Here it is fixed and reattached in its home in the Clark pump:
6. The work area after the job was completed. Big tool roundup to follow:
7. The infamous display, at long last displaying what it should…for now: