Saturday 29th March 2008 (5hr 5min)
Dorothy and I continued our riveting partnership by completing the internal skin to spar and mid span rib rivets. I then inserted the two root ribs and completed the riveting of these plus the rear spar and the tip rib after fixing some bad rivets in the rear spar assembly that had been identified in the inspection. Being mostly around the edge of the skin, these rivets were easy. Only the three rivets through the two root rib flanges and the forward spar were a little tricky but the air squeezer easily got these done as the access is much easier that the similar joint at the root of each elevator.
Mick Bevin (my inspector) had suggested replacement of a number of rivets in the elevator stiffners. These had been put in before I realised the importance of adjusting pressure on the rivet gun and I had mashed some rivets by using too much pressure. Drilling out rivets is something you get a lot of practice at and I can generally get them out without touching the hole. Still, the process of setting the original rivet stretches the hole so you need a fatter replacement rivet. One way of making a fat rivet is to pre-squeeze a rivet of the next length up so that the shank expands and shortens. This will fill up the slightly enlarged hole. Doing this with an air squeezer is not easy but it is one way of developing a sensitive trigger finger.
Next, I weighted the elevator in the closed position with building sand divided among several of Dorothy's freezer food bags. Some people go to great lengths to get solid rivets through the bottom skin into the spar. I just went with the Vans suggestion and pop-riveted the join. Maybe I should have tried harder as the results were not wonderful, with a depression around each rivet. Good thing they are on the bottom. While the elevator was weighed down, I also riveted the root rib to the top and bottom skin and the trim spar to the bottom skin.
Riveted VS skin to forward spar and mid-span rib. Riveted in VS-706 tip rib VS-704 root rib and VS-705 nose rib. Replaced bad rivets in rear spar assembly and riveted it in place. Levelled table, drilled out and replaced bad rivets on left elevator top and bottom skin stiffners. Riveted top skin to the spar. Weighted left elevator and pop-riveted main spar to bottom skin. Riveted E-905 root rib and E-907 trim spar to bottom skin. Replaced faulty rivets in right elevator stiffners.
Dorothy and I continued our riveting partnership by completing the internal skin to spar and mid span rib rivets. I then inserted the two root ribs and completed the riveting of these plus the rear spar and the tip rib after fixing some bad rivets in the rear spar assembly that had been identified in the inspection. Being mostly around the edge of the skin, these rivets were easy. Only the three rivets through the two root rib flanges and the forward spar were a little tricky but the air squeezer easily got these done as the access is much easier that the similar joint at the root of each elevator.
Mick Bevin (my inspector) had suggested replacement of a number of rivets in the elevator stiffners. These had been put in before I realised the importance of adjusting pressure on the rivet gun and I had mashed some rivets by using too much pressure. Drilling out rivets is something you get a lot of practice at and I can generally get them out without touching the hole. Still, the process of setting the original rivet stretches the hole so you need a fatter replacement rivet. One way of making a fat rivet is to pre-squeeze a rivet of the next length up so that the shank expands and shortens. This will fill up the slightly enlarged hole. Doing this with an air squeezer is not easy but it is one way of developing a sensitive trigger finger.
I put on the elevator horn without any problem and then went on to rivet the elevator top skin to the spar. About 3-4 rivets either side of the hinge openings could be reached with the 4in thin-nose yoke.
Next, I weighted the elevator in the closed position with building sand divided among several of Dorothy's freezer food bags. Some people go to great lengths to get solid rivets through the bottom skin into the spar. I just went with the Vans suggestion and pop-riveted the join. Maybe I should have tried harder as the results were not wonderful, with a depression around each rivet. Good thing they are on the bottom. While the elevator was weighed down, I also riveted the root rib to the top and bottom skin and the trim spar to the bottom skin. The trailing edges did not initially lie exactly on top of each other and had to be pulled into alignment and clamped using side-jaw clecos. This makes we worry about twist. Some builders have reported that they have perfectly straight trailing edges but with the two trailing edges aligned with each other only one elevator horn lines up with its elevator while the other one is well off. The solution seems to be to undo the end rib rivets and/or the trailing edge rivets, get everything into alignment while weighted down and re-rivet. I hope to avoid this by riveting both elevator trailing edges while mounted to the HS assembly and held 'in trail'.
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