Stainless Steel Pontoon?

Discussion in 'Boat Design' started by Carlazzomark, Jun 24, 2013.

  1. Carlazzomark
    Joined: Oct 2006
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    Location: Michigan

    Carlazzomark Senior Member

    Can anyone advise me on the advantages/disadvantages of stainless steel pontoons versus aluminum?

    I want to build my own pontoon boat here in Italy, and one of the few sources for pontoons makes them only in SS.


  2. BMcF
    Joined: Mar 2007
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    Location: Maryland

    BMcF Senior Member

    Stainless steel pontoons would be a lot better in salt water service, assuming the appropriate grade of stainless steel is used. Aluminum pontoon boats have a generally poor reputation around my area (lower Chesapeake) because the thin aluminum hulls so often fail due to corrosion.

    To be fair, the failures can almost always be attributed to poor hull maintenance and use/abuse of entirely incorrect paint "systems". Very few smaller yards or boat lots around here are really familiar with the correct paint systems and procedures for aluminum hulls and many pontoons are owner-maintained too.......
  3. JSL
    Joined: Nov 2012
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    Location: Delta BC

    JSL Senior Member

    SS is okay but not really a good structural material. Be aware of the characteristics & follow prudent construction practice. SS can be prone to work hardening (as aluminum, or steel, but more so) and corrosion. You don't want 304. But 316(L) & 317(L) is okay. Make sure you do not have any noble materials (copper, graphite, etc) in/on the pontoon. And, ferrous material (steel, iron*) MUST be kept away or you will get carbide precipitation... looks like rust.(*including tools)
  4. Carlazzomark
    Joined: Oct 2006
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    Location: Michigan

    Carlazzomark Senior Member

    Thanks for the replies. The boat would be used on Lake Lugano, fresh water.

    It sounds to me that SS really does not have any advantage over aluminum. There is a Polish company that sells pontoon kits of aluminum, or it might be cheaper just to buy an old boat in the US and have it shipped over. I plan to re-do everything from the deck up, so as long as the 'toons and transom are good, I should be fine.

    I am looking for something in the 20-23 foot range, most like pontoons rather than tritoons, and I will buy a 40 hp motor here (no license required for 40 and under, plus gas on the lake is $10 per gallon).


  5. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    The replies are overly simplistic, a bit inaccurate and don't address the real issue - weight.

    A simple comparison, of the physical properties of the common salt water versions, of these alloys, makes things pretty easy to figure out.

    The overly simply answer to your question is no, stainless wouldn't be a very good idea on a pontoon boat, but mostly because of weight. The choice of pontoon style of hull means; that performance isn't a concern, nor sea keeping ability, efficiency, maneuverability, etc., so maybe you can justify the stainless tubes to a small degree, but generally nope, just so darned heavy, considering they'll have to be able to tolerate some slamming loads at speed, so paper thin sheets aren't practical.

    Of course this assumes round tube pontoons. Now reasonably shaped tubes might be a better route for a pontoon boat, though she'll likely cross over to the cat category. The weight issue will persist, but the boat will perform better.
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