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Thread: keel voids

  1. #76
    Join Date
    Sep 2001
    Location
    San Rafael, CA
    Posts
    3,621

    some thoughts on filling the void

    Kyle, What are you going to do about the space?
    Could be left alone - drain plugs have been put in.

    At the time I discovered THE VOID, I was upset.
    Didn't like the idea that more than a ton of lead was essentially loose in the bilge.
    I've talked endlessly about this - but here are a few thoughts.

    Poured in 6 (probably more, lost track) gallons of epoxy. I didn't know at the time it would
    end up with that many. Maybe vinylester or polyester could be used. Or concrete if it could be
    made fluid enough to get in all the crans and nookies. Convinced self that epoxy, even
    though the surfaces inside cannot be prepped, epoxy promises some superior qualities.
    There was, still is, considerable junk in the cavity that we surmised was there to shim the casting
    'in place' until the top encapsulation took place. Epoxy might cohere it better, even though it
    might still be sodden.

    Anyway, drilled through the hull into the cavity at the 'top' of the casting - about where the main
    bulkhead is. Must have made exploratory holes to find the top of the lead. Then drilled a larger
    hole to get the end of a long gas funnel to fit. Has to be loose in the hole Did the same on the
    other side. Drilled small holes like yours at about the top of the lead at the lower end, both sides.

    Trying to remember if I thinned the two-part laminating epoxy with xylene...to get it to run
    better...can't remember. Filling the void isn't essentially structural. Doesn't take much thinner,
    shouldn't use too much, getting it to flow. (Logged the experience into the Forum at one time.)
    You want the mixture to flow as long as possible. Visualize that the levels will be horizontal.

    A professional would proceed from the low end, and work toward the front using 1/4" holes &
    dowel plugs to tell him where the level had got to. I did it from the front, not knowing any better!!
    Use the drawing on page 144 in the Manual to help locate the ballast from the outside the hull.
    Explained elsewhere how to use it to create an accurate picture giving close measurements..


    Spread out the filling events over many days because I didn't want the epoxy to smoke.
    Believe you can build heat to where it will damage the hull. When I was going down to the
    boat regularly, the first thing was to have a filling session, check on the progress.

    Banged in wood plugs to stopper a telltale hole when it began to leak plastic.
    I think it would help to do this on mornings of 40, 50, 65 degrees, with slow hardener.
    Make sure the epoxy is no-blush, so the layers inside get glued together.
    I've always mixed into plastic graduated quart 'cups'. Premarked with a sharpie the
    proportions are mixed together quickly and funneled immediately into the fill holes.
    Not too many holes. OK? 3/4ers of a qt is about as much to mix and pour before exotherm.
    On A338's thin hull, it was easy to feel the heat. 2 or 3 fillholes speed it up. Lead is cold.
    After cure...dished the holes and filled back with epoxy and disks of matt and fabric.

    What I didn't do, but may work in your boat is to forget drilling holes in the sides of the
    hull and do the filling from inside...if you have the cabin sole removed. Drilling location
    holes near the hull will be fun. May get lucky if they didn't slobber too much down the
    crack between ballast and hull. Never explored this option myself.

    In LittleGull, I discovered before it became a catastrophy, that the end of the ballast at
    the sump had not been glassed in. I think it may have been left that way
    SO THAT THE BALLAST DRAINS INTO THE SUMP. But it was so funky it became
    evident that it was just a sloppy job. Ghastly, fixing it with chisels and grinder....:

    If you're using polyester, you'll have to drill more holes to get it in faster... before it smokes.
    I don't think I could do it! Possible, if one had total access to the top of the ballast inside
    the boat - and prepped everything ready... having all fill holes drilled the whole length,
    it could be done with polyester.......and a full air mask. Or spare set of lungs.
    .................................................. .................................................. ......................................
    .................................................. .................................................. ......................................
    [later EDIT. This is a comment on Mike's next post #77]

    Wonderful find! Really! Urethane foam has a violent reaction when combined, compared
    with the much more tame reaction of the SICOMIN. Wouldn't use U-foam inside because
    reaction gasses are very toxic. It's not strickly closed cell and not structural. When used
    (as the Sicomin video demo shows epoxy foam) as a rudder foam, it always seems to turn
    out to be a mistake. (viz Foss Foam rudders.) Sicomin PB250 is a dream come true.

    I'd see if the Ensign shop could give us an interview. Be great to find out if they foam
    the ballast wide open or cover it and do the hole drilling ballet. Urethane can build up
    tremendous pressure if captured without a way out when expanding. The epoxy foam
    seems much gentler...but imco needs some expert advise. It's got to fill every bit of the
    void to be totally effective. Wouldn't want a puddle of water developing somewhere
    inside the cavity. (If my experience is typical: using 6-7 gals of liquid....there is 0.1337cu.ft
    in a gallon (0.1337x7=0.9cu.ft)...so it looks like a one cubic foot kit would do it....??

    This Sicomin epoxy foam looks PERFECT. And whatever it costs, it'll be way cheaper
    than filling with liquid epoxy!!!
    Last edited by ebb; 11-10-2014 at 01:11 PM.

  2. #77
    Join Date
    Jan 2004
    Location
    Scarborough, Maine
    Posts
    1,439

    Another way to fill the void

    I had a discussion with a fellow from Ensign Spars about a year and a half ago. Turns out they use an expanding EPOXY foam made by Pro-Set to fill the keel voids in the new Ensigns. A closed-cell AND structural solution.

    I couldn't find any retail outlet for the product at the time. He said it was formulated especially for them, but the they might sell it at some point. (A quick look and I don't see on the Ensign site yet.)

    Here's a video of the Pro-Set epoxy foam in action.

    But if there is a retail outlet for the stuff, it seems like Ebb's fill from the top method would be ideal with this stuff...

    < Pause for Google Search... >

    Found one! Sicomin Foaming Epoxy

    And another! Matrix Composite Materials (in the UK)

    It appears expanding epoxy foam has hit the market!

    ----

    And Sicomin has a video using the expanding epoxy foam too.
    Last edited by mbd; 11-10-2014 at 06:16 AM. Reason: Add link
    Mike
    Totoro (Sea Sprite 23 #626)

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