Step 5.2 Rear spar

With the EAA work benches complete, I moved on to the rear spar assembly.  The rear spar is really just a thin piece of sheet aluminum bent into a Z shape to provide flanges to attach the aft edge of the wing skins.  The bends in the spar flanges also provide a great deal of stiffness to the spar.  On the forward face of the rear spar the wing ribs are attached while the aft face provides the aileron and flap bracket attachment.  On the ends of the rear spar are 'doublers' which are additional layers of metal sandwiched together to provide addional strength.  The first task is to cut the doublers to size.

The smooth the plates out with a file and the Scotch-bite wheel.

 Once the individual pieces are looking good, the whole thing is clecoed together.

Chuck came over and lent me a hand getting the rear spars riveted.  Since the rear spar is fairly small, we were able to use the squeezer all the way around.

I put blue tape over the holes that will not be riveted at this time.  I know from past experience, that once I get in the riveting groove, every hole gets a rivet -- It's much better to block off the unused holes now than to have to drill them out later!

With the rear spars riveted, it was time for priming.

Next up:  Rib straightening and riveting the wing frame.