Cummins Marine Diesel Repower Specialists Forums All Other Marine Diesels Genset Heat Exchanger Maintenance

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  • #14988

    Rob Schepis
    Forum Moderator
    Vessel Name: Tenacious
    Engines: 6BTA 5.9 330's - "Seaboard Style"
    Location: Long Island, NY
    Country: USA

    Pulled the heat exchanger off my Kohler 5EOZ genny yesterday and pressure tested it last night.

    I looped the seawater ports with one of the seawater hoses to close off the seawater side and I used the zinc port for pressure test. It takes a 1/4″ zinc so I used a 1/4″M to 1/8″F adapter bushing and then connected my 1/8″ fittings, gauge and schrader valve.

    I put plastic bag material over the coolant ports this way if I did get a loss of pressure I would know if it was internal or if it was simply one of my test fittings.  If internal, the loose plastic bag would tighten up.

    It held 15psi for a several hours before I left the air out. Next I will acid clean (at 10:1) and then do the pressure test again.  More to follow…..

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  • #15052

    Rob Schepis
    Forum Moderator
    Vessel Name: Tenacious
    Engines: 6BTA 5.9 330's - "Seaboard Style"
    Location: Long Island, NY
    Country: USA

    Phil, In my reply to your inquiries I should have also mentioned that I flushed with fresh water after the acid and again at the end..

    #15048

    Rob Schepis
    Forum Moderator
    Vessel Name: Tenacious
    Engines: 6BTA 5.9 330's - "Seaboard Style"
    Location: Long Island, NY
    Country: USA

    A few answers.

    Phil, Following your same sequence:

    1.  No can do.  I do not have gauges on my genset, only alarms.  All was well before this heat exchanger maintenance, I simply chose to do it 100% in the spirit of preventative maintenance.

    2. I’ll pop the end cap in 3 seasons and take a peak at the tubes and go from there.

    3. Approx 30 minutes

    4. A few ounces in that 2 cup measuring cup.  I went about other things after pouring it in but maybe it was in there 30 minutes or so.

    As far as acid vs. ultrasonic on the seawater side of coolers:  I’ve always followed Tony’s writings on maintenance and other things and he has reported that ultrasonic cleaning on the salt water side does not do much for the layers of deposits, old zinc, mussels, marine growth, etc., only manually rodding out the heavy stuff and proper acid based cleaning solution.  Plus I don’t own an ultrasonic cleaner!     Hope this helps. Appreciate the interest.

    #15046

    Philip
    Participant
    Vessel Name: 2007 35’ Cabo ‘FUGA’
    Engines: Cummins QSC8.3-540’s
    Location: Long Beach, CA

    A few questions.

    Rob,

    A few questions. 

    1. When you get her all back together please post your operating results and any cooling improvements you notice.

    2. How long till you intend to do the same cleaning again? 

    3. How long did you leave the 10:1 acid solution in contact?

    4. What ratio soda ash did you use and how long did you let it neutralize for?

    i don’t mind the personal shop rate as I enjoy working on my boat myself and was planning to go the ultrasonic route. Wondering how much difference/better hydrocloroc acid vs. ultrasonic is and if acid can be used at 2 or 3 year intervals.

     

    Phil

    #15044

    Rob Schepis
    Forum Moderator
    Vessel Name: Tenacious
    Engines: 6BTA 5.9 330's - "Seaboard Style"
    Location: Long Island, NY
    Country: USA

    Thanks for the comments and info. Yes, could be a tough one to justify to Joe Customer at “shop rate” but at the current DIY rate ($0.50 an hour last time I checked) it’s fun to get into this type of stuff….. By the time I get it prepped, painted, reinstalled and coolant replaced it’s easily a full days work start to finish…

    #15039

    Tony Athens
    Moderator
    Vessel Name: Local Banks
    Engines: QSB 6.7 550 HP
    Location: Oxnard, CA
    Country: USA

    You know,  this looked very tedious, but the end result was worth it.. Now, you know for sure…………….A very good job and thanks for documenting it…………………..FYI, down the road, a 10-25 Lbs bag of common soda ash in super cheap and nice thing to store in lidded 5 gal bucket for all sorts of things that can happen when you need a  vary safe all purpose  acid and safe  “neutralizer” around the house.. Works great on animal “piss” too.. But, it won’t double when making bread..  I think is was used in the old days  to help soften water when washing cloths?

     

        Tony

    #15028

    Rob Schepis
    Forum Moderator
    Vessel Name: Tenacious
    Engines: 6BTA 5.9 330's - "Seaboard Style"
    Location: Long Island, NY
    Country: USA

    Cleaned, Neutralized and PSI Tested

    Acid cleaned 10:1 pool acid, neutralized, rinsed and pressure tested @ 20 psi.  Mission accomplished..

    #15017

    Rob Schepis
    Forum Moderator
    Vessel Name: Tenacious
    Engines: 6BTA 5.9 330's - "Seaboard Style"
    Location: Long Island, NY
    Country: USA

    Pressure Testing – Before & After Acid Cleaning

    Agreed David, thanks.  I did mention that at the end of my post.  The reason I opted to do “before & after” was that if there is a leak afterwards it would be interesting to know if it was at all present before the acid cleaning…

    #15016

    David Marchand
    Participant
    Vessel Name: Atlas Pompano 23
    Engines: Yamaha 70 hp 4 cylinder/cycle
    Location: Punta Gorda, Florida
    Country: USA

    I think I would pressure test again after acid cleaning. Often scale blocks leaks, so when the scale is dissolved…….

    David

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