Saturday, July 27, 2013

Watermaker Update!

The past few days we have been running Viking Star's home-built watermaker (follow the whole story via this label link:  http://mvvikingstar.blogspot.com/search/label/Water%20Maker ).  Have put about 160 gallons into the tank and have a few more thoughts.

Do we still think we need it?

First off, we once again got into the conversation with a fellow boater about the 'need' for a watermaker.  This fellow has done a bit of cruising here in the BC area, and commented they never had issues finding water - even all the way up to Alaska.  It is something we have heard before, and yet we fired up our watermaker after leaving Ganges.   Why??

Well - see I think this is again a situation where you need to consider the cruising lifestyle of who is giving you an answer.  As with our questions about the South Sound, where we got 'it was great' or 'there is nothing down there',  I think it really depends on if the person we were asking liked to anchor out (it was great), or liked to go into full service Marinas (there is nothing down there).

And to the same end I am beginning to think the 'Yes, we use our Watermaker all the time' vs. the 'We never had any problem finding water' might fall into the same camp.

I have no question that water is available anywhere in the world, it really comes to a question of access and cost.  For our experience cruising in the South Sound last year, there was easy access to water at many of the public docks. And as such we did not use the Watermaker at all last year.  This year we had planned to take on water in Friday Harbor (which we did), with the next stop at Ganges where we again knew water was available on the public dock.  But in the end we did not take water at Ganges.    Oh, we tried - as we came to the dock a space opened up just our size, and while Kristi was prepping the boat for a Starboard side tie we got within 5 minutes when someone else planted themselves right in the middle of the open space.  So we went around and dropped Anchor (not in a great spot, but I was going to stay on the boat).   During the next three hours I watched boats come and go, and AT NO TIME was there a space large enough for us to get in.  It is Summer - and you see,  though water was available, but not accessible.  

Of course, we could have taken a slip in the local marina - that would have solved our access issue.  (At a cost of over $60 for the night).  We could have hung around for a few more hours, maybe into the evening, or we could do what we ended up doing:  Move on and run the watermaker.

So, in this example:  had we been the type to often pull into marinas, our access to water would be simple.  And I suspect that will be true elsewhere as we work more north.  But even this perhaps only in selected areas (Friday Harbor, Roche Harbor, Ganges, Nanaimo being the ones here we know of).  More likely, as water is a scarce commodity on many of these islands, even if we did pull into a marina many of them would not be able to let us take on 200 gallons.  Example: The upscale marina at Poets Cove limits you to 10 gallons / day, and the marina at Montague Harbor's water is undrinkable (they barge in water from Victoria for the local restaurant).  So, even the approach of Marina-to-Marina does not guarantee availability of water.  I have no doubt that if we wanted, we could find a marina with water every 10 days.  But even that brings up a point: when you also consider these places where water is available can easily be out of our way (we motored about 2 hours into and from Ganges primarily to secure water) - it does become one more thing to plan around.

Alright, back to that overriding question:  do you NEED a watermaker:  Well, for us - answered here in the RAIN FOREST of the Pacific Northwest - all I can say is:   We have already found it highly desirable; unless we wanted to purchase a night at the marina  or perhaps the fuel dock would have sold us water, like in Deep Cove - at $15/20 for a tank.    But for US at least, when you consider we are not interested in rationing our water (we use about 20 gallons / day between everything:  Showers, dishes, cooking, clothes washing, etc.),  and the time it takes to get into places like Ganges (which we would not go to this time of the year for any reason other than water),  I for one am glad we have our watermaker and expect to put many hours on it this summer.


Some Other Notes:
We have been operating in a rather high Algae area.  So much so that the 20u primary filter clogs up after 2-3 hours of run time!   The 1st time this happened, the system went out of normal operating range (vacuum on the pre-filters, and high pressure on the RO membranes) causing the single drive belt to squeal in complaint.   I changed the filter and all is well, but a few  notes from that experience:

  1. The Automation of the Generator is working so very very well, but there is NO automation of the watermaker.  That would be a major project, mostly around physically controlling the valves and such.  I am however going to look into monitoring critical pressures in the pre-filter and the high pressure pump, sounding warnings when they get a bit out of range and shutting things down when they turn critical.
  2. Until then, I need to shorten my check-in time while the Watermaker is running, check it every 10-15-20 minutes MAX.
  3. The high pressure pop-off did pop-off like it should have, but its capacity to release both the pressure the the flow from the CAT high pressure pump was not sufficient.  So, it in effect had no value.  Plus it did not reseated itself and continued to leak.  I have removed it for now, and will reconsider a replacement once I do some more research.
  4. I am not sure why the high pressure side went up when the pre-filters clogged, but one idea is a small bit of lint might have freed itself from the Oil filter element, passed downstream to partly restricted the pressure adjusting needle valve.  I am thinking this because I also had one of the three positions in the CAT pump drop out, resulting in a massive pulsation on the output.   After R&Ring the pump and inspecting  it, I seem to have cleared the issue - am wondering if some lint also got into one of the piston's valves, rendering that piston useless.  
  5. In any case I swapped the order of the Oil filter and the 5u filter, placing the 5u last.
  6. I had a stainless fitting split on me on the High Pressure hose.  Likely due to my ham-handed over tightening.  But I am SOO glad I have a pool of spares, just installed the spare hose and we are good to go.  Will get the original repaired / replaced this fall.

And on the primary 20u filters that get clogged up with Algae, I just clean them.   They get covered with about 1/4" of green 'slime' that I gently brush off in a pail of water, then I tie a string around them and dump them overboard for a few days floating around where lots of hungry guys get busy cleaning up the rest of the Green from the filters.  After that a few days in the Sun to 'bleach them out' and they are ready to go again.   

And this is why I selected the String type filters for the 20u, they are a lot more tough and able to stand this cleaning cycle.  I use the pleated accordion type filters to the 5u, as there is more surface area and they will last longer before requiring replacement.  (Not sure how well they will clean, mostly because anything in them would not be the soft green algae).

Or.....  maybe I should be saving this 'harvested' algae - drying it and selling as a health supplement!  Hum. . . . .

And one last thought -- I changed the order of the plumbing to run the seawater 1st through the Kubota's heat exchanger before sending it to the Watermaker system.  This was to raise the water temperature a little and improve the efficiency of the RO membranes.   I figure I am getting perhaps a 4-5 degree F raise doing this. However, someone asked a question about safety: what happens if the heat exchanger on the Kubota starts leaking and starts dumping antifreeze into the water before it gets sent to the watermaker.   

I think that is a great question...

So, I am going to be looking into coolant for the Kubota that does not involve the green antifreeze.  Maybe just plain water, or the Pink RV stuff?  Not really sure right now - I am more concerned about the mixed metals in the Kubota engine (steel and Aluminum) than freezing at low temperatures, and need to consider how to prevent excessive corrosion inside the Kubota...     Does anyone have some ideas on this???









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2 comments:

  1. Doesn't your heat exchanger have a zinc to compensate for the galvanic corrosion?

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    Replies
    1. Hi Tate,

      It does, but that protects only the seawater side of the heat exchanger and will do nothing for the 'freshwater' side. Not to worry, I found about low toxicity engine coolants and corrosion protection products, based on Propylene Glycol vs the highly toxic Ethylene Glycol (the Green Stuff). Example: "Prestone AF555 Low Tox Antifreeze".

      Given the US Gov allows a percentage of Propylene Glycol in our food as a preservative (common in wines I read), I think I will just move to that for the Kubota engine.

      We did our 3rd run of the Watermaker today and have just about filled the water tank (225 gallon). Can get about 2 hours on a filter before it needs cleaning. And in other good news: the new 'Integrated Engine Controller and Regulator' I built is allowing me to ALSO get 55A of battery charging from the 'generator' side of the system while making water! Something I could just not do using common commercial regulators.


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