Integral water tanks in fiberglass sailboats

Discussion in 'Boat Design' started by MJT, Jun 10, 2014.

  1. LP
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    LP Flying Boatman

    Curious if and what products MJT has come up with for coating his integral tanks.

    I've come up with a couple of products so far. One product is MAX CLR from Polymer Products in CA. They have a website that lists their products and all purchases run through eBay. They claim it is FDA compliant for food contact.

    http://www.ebay.com/itm/EPOXY-RESIN...259?hash=item48346dcc43&pt=LH_DefaultDomain_0

    Curious if anyone has any experience with the product.

    Another product is Master Bond. These products are FDA certified which makes me feel better than being only compliant. I haven't found any retail outlets yet though.

    http://www.masterbond.com/certifications/food-grade

    I located another medical grade epoxy, but the price is a bit much at $70 for 100 grams.


    I even ran across a comment on another forum that West System was being used for integral tanks by Beneteau.?????
     
    Last edited: Mar 22, 2015
  2. rasorinc
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    rasorinc Senior Member

    Any food grade quality epoxy would work for you with 3 coatings. No need for medical
    grade which has chemicals to keep it from dissolving from the medicines it holds.
     
  3. LP
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    LP Flying Boatman

    Thanks, rasorinc. I'm not overly familiar.

    Do you have any personal choices?
     
  4. goodwilltoall
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    goodwilltoall Senior Member

    For freshwater tanks I would use no type of plastic/epoxy whatsoever. I know you can buy decent water plastic water bottles that don't impart a chemical taste (even then beware) but what you are talking about is a one off. There is lots of controversy with BPA's leaching and would not risk it or put much trust in the FDA.

    So for water storage tanks I would use the food grade epoxy but only to secure a metal lath to the hull sides which you would have to carefully outline and almost mold beforehand. Once it sets then apply a 2 coat regular Portland cement mixture to the lath and fill it right away so it successfully cures. This is a very good way to store for long term as long as you minimize light exposure. Even though Portland is slightly processed its still a very natural material and insignificantly heavier for the small amount you will use.

    Peace.
     
  5. rwatson
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    rwatson Senior Member

    Oh - the FDA wants to poison us all ?

    Perhaps you would like to provide a link to an authoritive site that explains why Epoxies are a problem.
     
  6. snowbirder

    snowbirder Previous Member



    Common sense. The slightest difference in resin/hardener mix will leave you with either of these in your drinking water:

    a) BPA, an estrogenic compound which makes up the entirety of the resin side of epoxy

    or

    b) Aliphatic Amines, which make up most of the hardener side.

    Unless you have the mix ratio right, down to the order of parts per million, you get the difference leaching into your drinking water.
     
  7. rwatson
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    rwatson Senior Member


    Sorry, I wasnt clear enough - I was referring to

    While GWTA was saying NO epoxies were safe.
     
  8. snowbirder

    snowbirder Previous Member

    But what about all the chromium in portland cement?

    "Portland cement is caustic so it can cause chemical burns, the powder can cause irritation or with severe exposure lung cancer, and contains some toxic ingredients such as silica and chromium. "



    What is a good material to make highly shape conforming tanks from? One without poison?
     
  9. LP
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    LP Flying Boatman

  10. snowbirder

    snowbirder Previous Member

    Ah, ok. But stil, when you read the fine print on the potable water epoxy, they have minimum tanlk sizes in the hundreds of gallons to be sure the ppm leaching out is low enough.
     
  11. rwatson
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    rwatson Senior Member

    These people may be worth a contact - Epoxy made from Peanuts.
    http://ecopoxy.com/

    No MSD on their site, just a ubiquitous

    "Why Is EcoPoxy Safe?
    EcoPoxy does not contain harsh organic compounds or heavy metals. EcoPoxy is NOW "GREENSEAL" CERTIFIED"
     
  12. rwatson
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    rwatson Senior Member

    I dont know which ones you are referring to , but
    http://www.nuflowtech.com/manufacturing/epoxies/potableepoxy.aspx

    "The potable epoxies are UL certifed safe for drinking water and are most commomly used to coat domestic water systems"

    Small heating systems dont use hundreds of gallons



    These other guys, using Peanuts as a basis for Epoxy, may be worth checking out.

    http://ecopoxy.com/

    No hard data on their website, but an organic basis for the product bodes well - unless you are allergic to Peanuts :-(
     
  13. FAST FRED
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    FAST FRED Senior Member

    There are any number of companies that make custom bladder tanks.

    Weather you want to hold potable water , sewage diesel or lube oil , is your choice.

    On our vessel we chose a PAIR of bladders to fit in the water tank space.

    This allows 200G of water for southern cruising like the Bahamas or 200G of fuel to winter in .

    6 tanks 35G per tank, the choice is endless.

    Custom tanks only require a sketch with numbers and the size and location of fill and vents noted.
     
  14. snowbirder

    snowbirder Previous Member

    This is where I'm going. Once you consider the safety of DIY potable water tanks and all the time involved to make them, dropping bladders in is the way to go.
     

  15. goodwilltoall
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    goodwilltoall Senior Member

    Once in awhile (very rarely now) I buy one gallon plastic jugs of water. If you buy the clear jugs the water usually tastes OK however when buying the foggy white ones the plastic taste in the water is always clearly noticeable but both are approved by the FDA and "tested safe".
     
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