Brief Description: Blend out damage to L-bottom spar cap
Blend out damage to L-bottom spar cap
As reported back on 8/7/10, I damaged the left bottom spar cap while driving out a rivet. Fig. 1 shows the damage after initial attempts at blending. Much of the initial work was done with a rotary file. An aeronautical engineer suggested that I needed to remove all dents that could be stress concentrators before I installed a doubler to reinforce the damaged region. He suggested sanding with aluminum oxide abrasive (I believe that SiC abrasives can cause corrosion problems with the aluminum. I cut a small piece of garden hose to support the abrasive cloth. As shown in Fig. 3, I wrapped a strip of the cloth around the hose and clamped it in place with two clamps. As the cloth wore out, I just removed the clamps and slipped the cloth to expose fresh abrasive. After a couple of hours, I was able to get rid of the dents and smooth the blend as shown in Fig. 2.