drain holes

Discussion in 'Finishing Techniques' started by gahan, Feb 3, 2006.

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  1. Feb 3, 2006 #1

    gahan

    gahan

    gahan

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    I've installed drain holes in both alerions and wings at the inboard corner of each rib, do i have to put same in all tail components . I though one on each outboard horizontal components and one on bottom of vertical componets, plane is mini max and plan to build floats this spring.
    fabric is almost done with fusaglage to follow when I complete rigging o
    .
    f flight controls.
    It's friday and I'll have a productive week end on construction.

    reguards tom gahan
     
  2. Feb 3, 2006 #2

    orion

    orion

    orion

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    The drain holes in a structure provide two functions. The first is obvious in that it allows for venting of condensation. Ideally, in any enclosed volume you actually want two holes so that draining and venting are accomplished.

    And that brings me to the second function of the holes - pressure release. I am not initmately familiar with the Mini-Max but any time you build an enlcosed structure you want to make sure that there is no pressure build-up as the ambient temperature increases beyond that at which the airplane was originally built. The increased temperature will increase the internal pressure, sometimes to the point of significant damage. I remember early on in the construction of composite airframes where on several occassions parts (usually the control surfaces but a couple of times even the wings) of the airplane became nearly destroyed by the significant internal pressure that was developed when the airplane was left sitting on a hot tarmac.
     
  3. Feb 4, 2006 #3

    gahan

    gahan

    gahan

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    orion , thanks much I've already cut my little drain biscuts. I was sure that the tail components were going to be air tight and the storage barn where I keep the plane can be 45 in the morning and 90 at 4 in the afternoon. something would have to give.
     

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