Repairing crack in fiberglass boat

Discussion in 'Boat Tips' started by TDawgNOk, Oct 6, 2005.

  1. TDawgNOk

    TDawgNOk Gathering Monitor (Instigator)

    Messages:
    3,365
    State:
    Tulsa, Oklahoma
    Ok
    The New to me boat that I got has a crack about 6-8 in long in the hull.

    How do I go about reparing it?
     
  2. JERMSQUIRM

    JERMSQUIRM New Member

    Messages:
    13,145
    State:
    il-waynesv
    well ill let some of the experts on compounds help ya with that but one thing i can tell ya is cleaning and scuffing the area to be patched is the first step and most inportant. with the stuff that sticks to boats (crap in water, oil, and scale) the best patch in the world won't stick without proper surface prep.

    mark j and bobpaul should be able to provide some info on the stuff to use.
     

  3. bigflathunter

    bigflathunter New Member

    Messages:
    90
    State:
    Lawrence, KS
    If you don't care how it looks, go to systemthree.com and order their epoxy trial kit for $25. It will have enough epoxy and fiberglass to just slap a nice patch over it using good fiberglass cloth and high quality marine epoxy. I'd put a patch over the outside and inside for strength. That's if you don't care how it looks. Make sure you clean off any wax, oxidation, or lake grime and scuff up the surface first.

    To make it come out level, I'm not sure how I would go about it. Depending on the thickness of the hull and where it is, I'd probably cut a small oval around the crack, and then cut a piece of plywood close to the hull thickness to fit into the oval I cut with a slight gap. I'd then wet out some glass on the plywood with some spare glass hanging off and put it into the hole until it is level with the outside of the boat, or close. Cut a piece larger than the first one to use as backing inside the hull, and then glass that over the first piece. Fair the outside so it comes out level. Paint over and maybe you wouldn't know it was ever cracked.

    I don't know if that's the best way to do it, but the kit I mentioned would have all the epoxy and glass you'd need for the repair.
     
  4. TDawgNOk

    TDawgNOk Gathering Monitor (Instigator)

    Messages:
    3,365
    State:
    Tulsa, Oklahoma
    thanks bigflathunter,

    No, I don't particularly care how it looks. Just looking for a way to patch it for now. Later this winter when it is colder and then next summer I plan on pulling the floor out and redoing it and plan to do a REAL repair job on the crack then.
     
  5. JERMSQUIRM

    JERMSQUIRM New Member

    Messages:
    13,145
    State:
    il-waynesv
    lol. forgot about u. your working on a big project as well aren't ya? i used the wal-mart junk when i did mine years ago and didn't prep it as good as i should have. didn't last long. so the next time it leaked i cut the small whole from side to side all the way across and through several times with a chainsaw every couple of feet and tossed all the pieces into a dumpster. it never leaked again. :glare:
     
  6. TDawgNOk

    TDawgNOk Gathering Monitor (Instigator)

    Messages:
    3,365
    State:
    Tulsa, Oklahoma
    Um, no chain saw boat carving for me. Least ways, not yet. I need to keep the Slightly Haunted Indestructible Attack Ghetto Boat until I have saved enough to buy something else.
     
  7. catwacker

    catwacker New Member

    Messages:
    202
    State:
    illinois
    i have done quite a bit of fiberglassing. i think the best way to patch a 6" crack, from the outside only,would be to grind a v shaped groove thru the middle of the crack. then grind the outside surface down till you get thru the gelcoat and you can see the raw fiberglass. don't go any farther down than you have to. grind a spot 1 to 2 inches all the way around the crack. i would use a very thin strip of the fiberglass cloth saturated in the mixed resin into the crack itself, after coating area with resin. add more strips, getting slightly wider, untill surface is almost level , then put final piece on outside same size as ground out area. be sure to work out air bubbles as you go. give the patch plenty of time to set up, until it's not tacky. then fill surface bubbles ,if any, with thin body filler. sand and paint. i think this will probably hold untill you can get inside and reinforce the area with plywood and more 'glass. just a thought, good luck with it