Keel cooler sealing advice

Discussion in 'Diesel Engines' started by cal_d_44, Jul 11, 2014.

  1. cal_d_44
    Joined: Jul 2008
    Posts: 18
    Likes: 1, Points: 0, Legacy Rep: 35
    Location: Australia

    cal_d_44 Junior Member

    Hi all, I am after some advice I have a Nanni 55 hp engine that is designed for keel cooling, the manufacture recommends 1.85 sqr/mtr of surface area for effective cooling at >18 deg C water temp, and as I will be sailing mainly in the tropics. I have built one side, and together it will have about 1.95 sqr/mtrs of surface area and hold around 20 ltrs of coolant total (inc engine). I have built one side and have pressure tested it to 20psi the overflow/heat expansion cap is pressure rated to 1bar/14.5 psi, now in over an hour it lost 0.5psi through two small pinprick holes that I can not get too to weld them effectively. Any advice on how I could seal them. Was thinking of filling it with a thinned oil base paint pressurising it and then draining and washing the paint out??? each cooler side hold around 4 ltrs. Any advice would be appreciated.

    Cheers

    Cal
     
  2. CDK
    Joined: Aug 2007
    Posts: 3,324
    Likes: 148, Points: 63, Legacy Rep: 1819
    Location: Adriatic sea

    CDK retired engineer

    2C epoxy adhesive can seal the pinholes if you can reach them with a thin object and the holes are dry. If you have access to a pump, pull some vacuum so the adhesive gets in all the way.

    If you have no access at all, use the stuff that seals car radiators.
     
  3. cal_d_44
    Joined: Jul 2008
    Posts: 18
    Likes: 1, Points: 0, Legacy Rep: 35
    Location: Australia

    cal_d_44 Junior Member

    Cheers CDK :idea:
     

  4. gonzo
    Joined: Aug 2002
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    Location: Milwaukee, WI

    gonzo Senior Member

    The engine will overheat in tropical shallow waters. They can get to over 30C. Also, any coating you put in the heat exchanger will lower its heat transfer rating.
     
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