The W-1204G hand hold was bent per the plans to form the three sided rectangle that will be attached onto the main spar. After squaring the bends, the holes in the hand holds were dimpled. As with the left wing, all of the holes on the top were dimpled. However, two holes on the bottom were not dimpled - those being the two corner holes on the bottom of the hand hold which are at the forward outer corner of the hand hold. The reason for this is the wing tip lighting uses a fiberglass faring which attaches to those holes. The plan is to countersink the fiberglass because it is thick enough so the underlying surface will be left flat. RV-12 builders dimpling for flush rivets and also installing the lighting kit may opt to do this as well. After the hand hold was dimpled, it was riveted onto the main spar using AN470AD4-4.5 solid rivets as opposed to LP4-3 pop rivets.
Riveting the W-1204G hand hold onto the right spar with AN470AD4-4.5 solid rivets.
The W-1213R aft tip rib also required dimpling for the flush rivets being used on the RV-12 project. Dimpling the far aft pair of holes on the W-1213R tip rib poses a problem. There is not clearance for any of the pneumatic squeezer’s yokes and no room to insert the nail for the dimple dies that have the holes in them. So the last resort method, devised last fall by the DOG Aviation research and development department, of using a C-clamp to squeeze the dimple dies together was used.
C-clamp with the back cut out to gain clearance and the dimple dies with a short nail to hold dimple die alignment.
Assembly order of the dimple dies and the alignment nail.
Forming the dimple by tightening the C-clamp on the dimple dies.
After all the dimples were formed in the aft tip rib, it was riveted in place onto the rear spar assembly with AN470AD4-4 solid rivets in the place of LP4-3 pop rivets.
Using the pneumatic squeezer to rivet the W-1213R aft tip rib onto the rear spar assembly with AN470AD4-4 solid rivets.
Continuing with preparations for closing out the right wing tip, the process of removing the blue protective film from the rivet lines on the tip skins was started but not completed so that will be on the agenda for tomorrow.