Building the Pitts Wings

Whenever a hole is drilled in the spar, you need to add a doubler plate to increase the strength of this area.  

There's a test that Brent does with every batch of epoxy that he mixes.  He takes two pieces of wood and glues them together then sets them aside.  Once the epoxy is set up he breaks the pieces of wood apart and looks at where the break occurs.  If it breaks at the joint, he knows that this batch of epoxy was not mixed properly or it was bad for some other reason.  If the wood breaks and the epoxy joint is still intact, he knows that his wood joints are good.  If he finds that the glue joint was bad, he must remove all of the pieces of wood that he glued with that batch of epoxy.  This is a big job but it may save your life which makes the process necessary.