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Laminated spruce spar

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Jul 18, 2007
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I have build my Pitts laminated spruce spars using three to four .25" layers (depend of the spar thickness) and T88 glu.All was perfect,even all parts test never broke at the glu lines.A few days ago,I made the .75" holes where go the pin tubes use to hold the flying wires bolts,using a .75" hole saw.For one spar,the wood part that was inside the hole saw broke in three parts at two glu lines.The glu is there,but didn't penetrated at all.So even if the spar seems to be nice from the outside,I do not know if I can have the same problem on other glu lines....and what to do!!!!!!!!!!!

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