Brief Description: Debur and Dimple Bottom of Ribs/Spars
I used the Avery speed deburring tool to debur the outside flanges of the bottom of the ribs and rear spar. Then it was the right angle drill with a deburring bit and VERY low air pressure that was used to debur the inside flanges of the bottom of the ribs and rear spar. This went fairly quickly. Once everything was deburred, I used the pneumatic squeezer to dimple all of the ribs and the rear spar. This went very quickly and was very easy. Too easy in fact. I started moving along a little too fast and ended up putting my first extra hole in one of the ribs with the dimple dies in the pneumatic squeezer. Time to slow down and be more careful. I ended up putting flush dies in the hand squeezer and closing up the hole and moving on. I suppose I could have just squeezed a rivet in there instead. Maybe if there is a next time. Luckily this mistake will be covered by the skin and doesn't really affect the strength of the structure. Another thing that I noticed was the low durability of the SEM primer on the 3 outboard ribs. The shade of these ribs is just a little lighter than that of the other ribs and rear spar that were primed with SW 988. When I dimpled the SEM ribs, I noticed there were flakes of primer that were removed by the dimple dies around each hole. The SW 988 primer on the other ribs and the rear spar held up fine through the dimpling process and seems very durable. SW 988 will be used for everything remaining. It sprays better than SEM and is more durable.
Bottom of ribs and spars deburred and dimpled
SEM rib; pimer flaked when dimpled. Luckily only 3 ribs with SEM
