1. The Marketplace Forums can be useful for members who know one another well from forum discussions and offline communications and wish to post boatbuilding tools, drafting tools, molds and tooling, and other professional equipment for sale or trade. However, caution and good judgement should always be used. Especially when considering any business with anyone not already well known to you and trusted, due diligence must be used to confirm details and identity and be sure the transaction is safe before any money or property changes hands. Always use good judgement and perform due dilligence and follow these guidelines.

My little piece of peace

Discussion in 'Marketplace' started by masalai, Feb 5, 2009.

Thread Status:
Not open for further replies.
  1. groper
    Joined: Jun 2011
    Posts: 2,467
    Likes: 123, Points: 73, Legacy Rep: 693
    Location: australia

    groper Senior Member

    Im not talking about micro mesh filters, the unit i bought is a true reverse osmosis membrane system with a micro mesh filter and carbon filter inline with it. Its no different in principle operation to a marine desalinator... Its just the setup and support systems that need to be worked out... I believe it can be done for well under $1000
     
  2. masalai
    Joined: Oct 2007
    Posts: 6,823
    Likes: 121, Points: 0, Legacy Rep: 1882
    Location: cruising, Australia

    masalai masalai

    Hi groper,
    Have a read of the instruction/operating manual attached in the above post, and you will understand the difference MAKE sure that your water holding tanks are purged or all domestic supply as it usually has chemicals that will destroy your ocean water salt removing membrane... The difference is in the membrane and at around $1000 for a 40 inch one that will deliver 60 litres per hour treat it with care and respect...

    If you are thinking of increasing the product water output the flow rate needs to be maintained to flush the salt/waste water through the system as algai and other contaminants may grow and "kill the effectiveness" of the membrane. so in that case set the raw water through one membrane and from the waste side pass that through the next membrane, thus there will be sufficient flow to ensure the operating system will be flushed and discharged overboard and product (the clean fresh water will be almost doubled so long as the discharge flow rate is more than minimum recommended volume (by the flow meter on the waste flow) and that the product (fresh) water does NOT exceed the maximum rate for the membrane...
    148742
     
  3. groper
    Joined: Jun 2011
    Posts: 2,467
    Likes: 123, Points: 73, Legacy Rep: 693
    Location: australia

    groper Senior Member

    The reason my unit was cheap is because its very small... It only makes about 15-20 litres per hour... The plan was to run it for long periods or almost continuously whilst at sea and use rather large holding tanks. When returned to port, i can remove the unit, its very portable, and take it home to flush it and store it. Each replacement membrane is $70 and made in usa.
     
  4. masalai
    Joined: Oct 2007
    Posts: 6,823
    Likes: 121, Points: 0, Legacy Rep: 1882
    Location: cruising, Australia

    masalai masalai

    groper,
    - - - Again read the pdf - - - and check the suitability of your TOY membrane to process SEA WATER... It will still need a 80 psi pump as a minimum to push the fresh water through the membrane and that will probably BURST the membrane as domestic water is usually 40 to 80 psi - 800+ psi is used to extract fresh water from salty SEA WATER and domestic membranes will not handle salt and domestic water will KILL the membrane of a SALT water designed membrane / pressure canister...
     
  5. groper
    Joined: Jun 2011
    Posts: 2,467
    Likes: 123, Points: 73, Legacy Rep: 693
    Location: australia

    groper Senior Member

    Ok, masalai you are correct, the small household unit i have will not be suitable.

    So, this led me to some more research as i would like to find a cheap solution for water making on my boat...

    I Found in the US, several websites selling proper seawater RO membranes and fibreglass high pressure housings upto 1000psi. A 2540 membrane is $200usd or a slightly smaller 2521 can be had for about $150usd. The high pressure housing for teh 2540 runs about $450usd and the 2120 around $350usd.

    Then you need to get the pressure upto it and i can see several ways of doing this;
    1. use a high pressure pump - the proper marine units are quite expensive
    2. use a low pressure pump, plumbed through a mechanical hydraulic pressure intensifier.
    3. for maximum energy efficiency, would consider the use of a brine pressure booster to recover some of the lost energy and use it help boost pressure on the inlet side.

    I dont know what the pressure intensifiers cost these days, probably a couple hundred dollars, and the low pressure pumps are quite cheap. Add a few micro mesh filters and seawater strainer, should be good to go still under $1000 provided you can live with 'manual flushing' and 'sampling before collecting'.

    The hardest part is the energy requirements, a small system needs about 1Kw/h to run a decent size pump and with a 2540 membrane should deliver around 80litres per hour.

    Any thoughts on this?
     
  6. groper
    Joined: Jun 2011
    Posts: 2,467
    Likes: 123, Points: 73, Legacy Rep: 693
    Location: australia

    groper Senior Member

    somebody has even gone to the trouble;
    [​IMG]
     
  7. Manie B
    Joined: Sep 2006
    Posts: 2,041
    Likes: 117, Points: 63, Legacy Rep: 1818
    Location: Cape Town South Africa

    Manie B Senior Member

    I have been searching all over but cant find the Youtube article anymore.
    Maybe some body else saved it.

    The guy stripped a normal high pressure cleaner and coupled that to the membrane cartage. It really worked well and was much cheaper. More maintenance but everything easily obtainable parts.
     

    Attached Files:

  8. masalai
    Joined: Oct 2007
    Posts: 6,823
    Likes: 121, Points: 0, Legacy Rep: 1882
    Location: cruising, Australia

    masalai masalai

    Hi Groper,

    That is, as far as I recall, exactly what I suggested, and included that several in USA, (self build RO water-makers by hardware sourced parts), HAS been done many times, this and as published elsewhere,

    BUT THE FREIGHT COSTS from USA and Europe for small items are INSANELY EXPENSIVE....

    So I am seeking local supplies for the AUSTRALIANS and seeking a target of about Au$2000 for local supply of the parts...

    Hi Manie,
    I have seen a K'Archer "cheaper model" high pressure wash-down unit running on 220/240VAC using a bronze pump-head, (more than 100 less than 200 price range), but did not pay great heed to, (as I have one that cost Au$90 but need to inspect the pump head first before using it for my 'desal project'), because if the pump-head is cast iron, it will not last very long with 800psi salt water...

    - The membranes are not designed to sustain 'usual pump pressures' that are usually above 1600psi and beyond to somewhere around 3000psi and that would surely burst the membrane as well as the pressure vessel

    The "Filmtech-membranes-DOW.pdf" will print to A4 paper in portrait mode - 2 pages...

    The "RO-watermaker-flow-diag.jpg" will print nicely on A4 paper in landscape mode...

    The "DC_Operation_instructions.pdf" will also print to A4 paper and is 2 pages...
    149222
     

    Attached Files:

  9. groper
    Joined: Jun 2011
    Posts: 2,467
    Likes: 123, Points: 73, Legacy Rep: 693
    Location: australia

    groper Senior Member

    Masalai,

    Ive imported heaps of gear from teh USA, the frieght is not that expensive, in fact ive often paid more to ship an item of equal size WITHIN AUSTRALIA!

    They wont take very large items, (a 2540 membrane and housing might be a problem) but the best value shipping from the USA is via USPS (us postal service)... i never use FEDEX or UPS etc as these guys are way too expensive...
     
  10. masalai
    Joined: Oct 2007
    Posts: 6,823
    Likes: 121, Points: 0, Legacy Rep: 1882
    Location: cruising, Australia

    masalai masalai

    Tomorrow is "fueltank day" and I will have an additional 500litres capacity...

    Next is to sort out the water tanks (just clean and check) ready to take on 200 litres of water as once the fuel drums are stored access to check the water tanks will be very difficult as the fuel tanks will block access...

    I still have to empty the engine oil and fill both engine oil and sail-drive leg oil, check coolant, and wipe up any trace of dirt and oil from the engine bays...

    Weather is still cold and cloudy and offshore the wind is seat about 20 knots meaning the doldrums are still not operating and consequently seas are up in the Cairns to Samarai leg of about 480 nMiles... - - MAIN REASON IS - - - In cold weather I am disinclined to 'work outdoors'.... The seas are from the east even in a weeks time http://www.bom.gov.au/australia/cha...EST&area=Au&model=CG&chartSubmit=Refresh View
     
  11. groper
    Joined: Jun 2011
    Posts: 2,467
    Likes: 123, Points: 73, Legacy Rep: 693
    Location: australia

    groper Senior Member

    You wont get doldrums in the cairns to samurai leg until about november mas, its blowing its **** off up here right now, strong wind warning and all... its not so bad however, you will be running north with the swell and not punching into it...
     
  12. masalai
    Joined: Oct 2007
    Posts: 6,823
    Likes: 121, Points: 0, Legacy Rep: 1882
    Location: cruising, Australia

    masalai masalai

    The only seas I do not like are beam on... when the swell is long (100 metres, trough to trough) is OK but the short stuff from local influences is a pain... and I really relish a good 4 metre plus set heading for Samarai - - PERFECT...
     
  13. groper
    Joined: Jun 2011
    Posts: 2,467
    Likes: 123, Points: 73, Legacy Rep: 693
    Location: australia

    groper Senior Member

    you will be surfing all the way :D

    the return leg is the killer tho... if you plan your return november - december, even october can be ok, you might be able to ride the northerlies home too?? much nicer than punching into a strong SE all the way back to SEQ, been there done that :(
     
  14. masalai
    Joined: Oct 2007
    Posts: 6,823
    Likes: 121, Points: 0, Legacy Rep: 1882
    Location: cruising, Australia

    masalai masalai

    Surfing is the way - I like surfing, but could never master standing on those little boards, - - but sitting on the longer surf-ski's I liked, and I would paddle for miles to get the exercise...

    With recent experience on CNO, surfing was GREAT, and with the bigger propellers pushing me at better than 10 knots instead of the screaming engines to get 8 knots I look forward to some long rides - - as I was doing 19.5 knots surfing whilst heading up to the lee of South Percy last year... I hope to hold it for longer this trip... and the boat showed NO inclination to broach even when running at a quarter instead of keeping square down hill of the following sea...
    149362
     

  15. pdwiley
    Joined: Jun 2008
    Posts: 1,004
    Likes: 86, Points: 48, Legacy Rep: 933
    Location: Hobart

    pdwiley Senior Member

    It doesn't *get* cold where you are. I've just come back from a week in NSW, out where it drops below 0C at night. I was working outdoors all day and mainly stripped down to a T shirt. Daytime temps were over 15C.

    I escaped working on *my* boat in Tasmania because it's cold there (and I've other demands on my time). You're in the sub-tropics.

    Now, sloth is a perfect reason for not working, but blaming the cold in Brisbane is just unbelievable.

    PDW
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.
Thread Status:
Not open for further replies.