Completed blending the ribs into the leading edge of the spar. Will have to wait for the spotting compound to cure before completing the finish work. Also began drilling out the lift strut attach bracket rivets. When we replaced the forward spar on the left wing, we discovered that the original owner of this kit did not prep the spar and brackets correctly. He did not sand or wash either of them. Both mating surfaces have to be sanded to bond correctly. The aluminum spar and the powder coat of the bracket, must be sanded with 320 grit and washed with acetone to eliminate any oils and fine dust. This will ensure a proper bond for maximum strength.
As I drilled out each of the rivets the attach brackets popped away from the spar. No adhesion. The Hysol bond was non existent. The aluminum spar and the bracket have to be prepped properly for the bond to be 100 %. The only thing holding these brackets in place were the rivets. Its true that the Hysol is used to insulate the steel bracket from the aluminum spar but, it is also a part of the structural design. Both are used in conjunction with each other. The Left wing was the same way when we rebuilt it. Now the Right will be correct as well when complete.
Blending complete, waiting for the spotting compound to cure.
If you look closely at the left side of the bracket,, you can see where it popped away from the spar.
