Mahogany boomkin bolt holes

  • December 20, 2012 2:26 PM
    Message # 1164293
    Deleted user

    I just received my new mahogany boomkin and rudder cheeks. I am going to seal them with penetrating epoxy like I did for my bowsprit. I was wondering if it would be acceptable without losing any strength to over drill the bolt holes by about  1/8” and fill it with epoxy and then re-drill the correct smaller size for the bolts through the solid epoxy. I do this for deck hardware but just wanted to get someone else’s thoughts on doing it to the boomkin.

  • December 20, 2012 2:47 PM
    Reply # 1164309 on 1164293
    When/If you do this make sure you use high density filler that is well mixed and have no voids when you fill the holes.  I've seen this done in some places that take very heavy loads.  
  • December 21, 2012 6:52 AM
    Reply # 1164717 on 1164293
    Instead of overdrilling why not use a low viscosity epoxy (West Systems) that will 'soak' into the wood.

    It is how I sealed the bolt holes in my new bowsprit.  I further thinned the West Systems epoxy a bit with a small amount of acetone and 'painted' the interior a few times with Q tips.

    Additionally I 'countersunk' the holes and used butyl rubber tape under the washers and/or bolt heads.
  • December 21, 2012 10:04 AM
    Reply # 1164810 on 1164293
    Deleted user

    Thanks Tate and Mike.

    Mike I did the same thing on my bowsprit. I did find I had to run the drill bit through the holes to get the bolts to fit. I used the Marine West penetrating epoxy. It flowed really well. I just wanted to be sure that by running the drill bit back through I didn't remove the protection. I think it would be fine. I think I will again use the penetrating epoxy again.

  • December 23, 2012 8:22 AM
    Reply # 1165773 on 1164293

    I recommend using a drill bit 1/32" larger that the bolt size.  Tape the underside of the hole, pour in thinned epoxy resin, and let it sit a while.  Before it hardens, pull the tape and drain out the excess.  You should have a good coating of epoxy on the walls of the hole, and the bolt should easily slip through without having to redrill the hole.

    Just my humble opinion, after building a few hundred boats.