Drainage/Mouse Holes

Discussion in 'Wooden Boat Building and Restoration' started by nbehlman, Jan 6, 2016.

  1. nbehlman
    Joined: Aug 2011
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    Location: CT

    nbehlman Junior Member

    I'm in the midst of building my 14ft take on a jet powered Chris Craft. I recently got it flipped right-side-up and my next task is to correct something I messed up long ago... When I build the frames, I forgot to put "mouse holes" in the frames to allow water to drain between them. I need to figure out the best way to put those mouse holes in. I know there's probably no good way. I've considered using a flush cutting multitool to cut a slot. I also have a right angle adapter for my drill, which might work ok with a spade bit. Last resort would be the dremel tool. Does anyone have any bright ideas on how to do these mouseholes? I've attached a couple pictures of the boat.

    Attached Files:

  2. jehardiman
    Joined: Aug 2004
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    Location: Port Orchard, Washington, USA

    jehardiman Senior Member

    Drill and chisel. Go ahead and buy a Milwaukee right angle drill. Cheap compared to reframing. And remember to epoxy seal the inside of the limber ("mouse") holes.
  3. gonzo
    Joined: Aug 2002
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    Location: Milwaukee, WI

    gonzo Senior Member

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

    PAR Yacht Designer/Builder

    Using a large drill bit will not let you get close enough to the planking, so you'll be hacking and cursing mostly. Using a small drill bit at the corners, defining the height and sides will permit you to get in and connect the dots, so to speak. There's a few ways to do this and the fast way is a multi tool, though in some areas this might not fit well, so a coping saw, maybe with a spiral blade will do.

    The limbers and weeps along the forward keel and stringers will be the ones you'll have the most trouble with. The keel weeps need only be a diagonal cut, say 3/4" to 1" tall and angling down to the planking. A multi tool slid along on the keel and on the planking will be fairly easy, just watch the deadrise and slope of the bottom. The gusseted bottom/topside futtocks will be a bear in the forward sections too, because the angles change quickly, which is hard to eyeball with a hand shaking multi tool. In any case, save the chisel for something else, as these holes need to be cut as clean as possible to prevent rot and hanging up debris.

    Agreed once you've got them cut, they need to be sealed up with a few coats (minimum) of straight epoxy. A trick I use on these holes is a plain old kitchen sponge. Soak the sponge in epoxy and shove it through the holes, not being especially neat about it. Clean up drips and runs after you've got a section lathered up. Some sponges tend to break up with epoxy, so look for the synthetic ones, which seem to hold up better. Trust me on this sponge thing, it's fast and easy, if a bit messy (I'd rather have too much than too little in these areas). Some will try chip brushes, but you'll just leave as many hairs as you will goo. I like to lightly radius the edges of the weep hole openings to relieve stresses and permit coatings to stick well too, of course prior to epoxy. When you are just working on the frames, without the planking in the way and nice 1/4" - 1/2" roundover bit looks and works nice, but you'll have to use a file, sandpaper and some clever adjective invention exercises, now. Enjoy and no one is ever going to see these puppies, so if this is the worst, you've gotten off light.
  5. nbehlman
    Joined: Aug 2011
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    Location: CT

    nbehlman Junior Member

    1 person likes this.

  6. sdowney717
    Joined: Nov 2010
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    Location: Newport News VA

    sdowney717 Senior Member

    Drill the hole.
    Then use a sawzall blade clamped in a vicegrip to cut flush to hull planking.
    I also think a drill bit and drill can be used to square up the lower part of the hole.

    Another idea is use a circular saw cut through the planking into the frame.
    Remove the frame piece.
    Then reseal the plank slits with epoxy and you can glue in a thin slice of wood for the slit.
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