Monday, March 31, 2008

sandwiched

laid up all the carbon on friday, laminated the 3 bits together today. went fine, im happy with the amount of material, though this time i didn't reinforce the skin so much at the exit point and at the T-Joint. There was still ample weight of carbon in those areas but, the weakness last time was in how i dealt with the shear loadings.

Anyway i've improved the sheer resistance in a couple of ways, the result of which will hopefully be a long as prosporous, successful life for the foil: (carreer as a banker, hot wife and a couple of kids, townhouse in central sydney, big boat etc.)
  • First of all the T joint has no foam in it at all, just glue (sp microfibres). Last time it was foam and bog (Q-cells) with carbon strands in it, that wasnt enough.

  • There is some diagonal carbon along the front and back inside edges in the areas of high shear stress - i just chuked it in there with a big glob of glue in the middle; the idea is that when the mould squeezes together it gets pushed to the places the glue is oozing out.

  • you can see in the photo I integrated my carbon T-piece into the bottom surface, that pushed straight up into the foil and is encased in glue. hopefully there is no way in the world it will separate from the bottom skin, or pull out of the strut.

  • Lastly i plan to further tie the leading and trailng edges of the foil together around the T joint area and the exit area by making carbon 'wet bolts', at about 30-50mm centres for about 250 - 300mm, to join the top and bottom surfaces. ill put photos of them up when i do them.

Also i cut my finger twice in the same spot with the grinder. first time with the cutting disk then again with a sandpaper disk. the second time it went straight through my nice fresh band-aid. I put a heavy glove on after that. When you wear a glove you might as well have a bit of wood for a hand.

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