Compartment Seam Sealant

Discussion in 'Materials' started by Dakotaly, Jun 19, 2024.

  1. Dakotaly
    Joined: May 2023
    Posts: 20
    Likes: 1, Points: 3
    Location: Ozarks

    Dakotaly Junior Member

    On my current and first boat build (aluminum). I am learning how much aluminum can warp and how good fit-up needs to be to prevent blow out. Since I'm hand cutting these pieces fit up isn't perfect and I'm already designing work arounds for my next build to "hide" imperfect fitment. The original plan was to weld all compartments and lids completely through with a small drain plug to pull incase of water intrusion. I'm now learning that isn't feasible to make it look good without better fitment, better welding machines, welder, and a lot more time . What I can do is stich weld it to minimize heat but I still want the seams to be waterproof and not have a visible but or T joint. I know that 5200 is the marine go to. In my case it seems to be a little over kill since it's not holding anything together it just need some kind of caulking to put on edges and corners that is a little cheaper than 5200 ideally. Paintable is a plus but not necessary. Open to other options beside sealants or caulk.

    TLDR;
    Best caulking for waterproofing aluminum boat interiors?
     
  2. gonzo
    Joined: Aug 2002
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    Location: Milwaukee, WI

    gonzo Senior Member

  3. Dakotaly
    Joined: May 2023
    Posts: 20
    Likes: 1, Points: 3
    Location: Ozarks

    Dakotaly Junior Member

  4. Milehog
    Joined: Aug 2006
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    Location: NW

    Milehog Clever Quip

    Look at RV sealants too.
     
  5. jehardiman
    Joined: Aug 2004
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    Location: Port Orchard, Washington, USA

    jehardiman Senior Member

    In the shipyard we used butyl rope or butyl duct sealant (aka monkey sh*t).
     
    Howlandwoodworks likes this.

  6. comfisherman
    Joined: Apr 2009
    Posts: 830
    Likes: 420, Points: 63, Legacy Rep: 10
    Location: Alaska

    comfisherman Senior Member

    Sika flex 291, it's 40% less than 5200 and 85% as good. We use prodigious quantities of it on all manner of steel, aluminum and glass boats.
     
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