Do you recognize this foot print? (Wood bug)

Discussion in 'Materials' started by CanuckGuy, May 18, 2009.

  1. CanuckGuy
    Joined: Aug 2008
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    CanuckGuy Junior Member

    I'm working with a batch of Khaya Ivorensis raw lumber. (10" wide, 4/4" and 8/4", 10+' long, being used for laminating a 5"x10" keel).

    There are a couple of boards that have small sections in them with many many bore holes. I've attached images.

    When I probe the holes with a nail driver or knife, it feels crusty and hard like dried pine sap. There's absolutely no moistness, no funky feeling to it. The boards are kiln dried, by the way.

    This particular part that I'm showing here had a high density of infestation and I obviously just cut it out.

    However every here and there, there will be one whole (through and through) in the wood. Given that I'm dealing with rather large pieces which I'm laminating into a keel, I don't feel like scrapping the one end of the board simply because there was as single bore hole.

    Does anyone know about these bugs? They really do seem to be long dead, but do they leave eggs? Should I be worried that there might be places where there's dormant eggs in the wood? Will sealing them in Epoxy fix my problems?

    A couple of the holes I've simply drilled through with a larger drill bit and filled with thickened epoxy. Anyone see a problem with this?

    Any information is much appreciated.

    Attached Files:

  2. Petros
    Joined: Oct 2007
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    Petros Senior Member

    I am no expert on pests, but I am a engineer familar with wood structures. It seems unlikely that the bug would survive the kiln, but I would probably treat it with the chemicals they sell at hardware stores for treating wood eating pests on houses (Home Depo, Lowe's, etc. sell them, and they are effective).

    A few small holes will have no noticeable affect on strength on the finished assembly. I routinely used similar looking wood, or salvaged wood with nail or screw holes, on laminated assemblies and it has never been an issue. Of course this assumes you can make an accurate assessment of the extent of the damage, and there are not large hidden pockets.

    Filling the holes with a filler as you did is an excellent idea, as long as it is not too brittle compared to the wood. Personally I just ignore the small ones, and large ones that might show, I drill though and glue in a wood dowel. I think the biggest risk is to create a pocket where moisture will be trapped if it should seep in (which it will eventually no matter how well sealed).

    The strength of wood is rated assuming there is a certain number of hidden defects in the grain of the wood, so usually there is an ample safety factor for small defects. If the assembly is glassed over, much of the strength comes from the fiberglass layers anyway, and the wood is only a filler core. Many assemblies will depend on a combination of the wood core and fiberglass sheathing for strength, Either way there will be no noticeable affect on overall strength with a few small holes through the core wood.

    In my professional opinion the concern would be largely cosmetic. But even so, I personally would try to use the wood so these kind of defects will only occur at lower stress areas of the assembly. i.e. at the edges and near the center of the thickness. It would not bother me at all to use such lumber, I have many times before.

    Good luck.
  3. apex1

    apex1 Guest

    Mahogany infested that deep and wide (there are deep pockets to assume) is useable in a keel application. If you have a chance to fill the pockets with honey to mayonnayse thickened resin (Epoxy) injected through the surface holes that would be a sufficient aid to keep the original properties at level. Does´nt matter how perfect.
    But you must not have any doubt about insects and infections at present! Kiln dry kills every living organism! (apart of some funghi).

    Cut out the main crap and use the rest of it!


    Using it on another structural part of a seagoing vessel is a NONO! Whatsoever Architects may say, landbased structures have as much in common with a boat as lemons with a apple.


  4. CanuckGuy
    Joined: Aug 2008
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    CanuckGuy Junior Member

    Alright. Thanks for the input.

    My main concern was about the remaining life forms in there. As far as the lumber that I am using is concerned, there is only the odd hole here or there. These particular shots are of a part that I have already chucked, but found useful to document.

    Once again, thanks.
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