Tanks ready to proseal
Today (Friday) I took what a fellow builder has termed an “illegal build day”, meaning instead of going to work, I spent a full day in the garage. I do that periodically. Hey, I don’t take real vacations and my company likes for me to “decompress” every once in a while.
Yesterday, I dimpled ALL of the leading edge skins (two tanks and two outboard leading edge skins) in just a few hours after work (ok, more like 4-5hrs). This is the first time that I have had a chance to use the dimpling tool that I got before I started the wings. It is so much better than whacking the C-frame dimpler a million times. It was amazing how fast and easy dimpling a whole wing skin could be.
Earlier in the week, I finished edge deburring the tank skins and scuffing the insides where the prosealed ribs will go. My standard edge deburring method is to first use a vixen file square with the edge. I do this until no shear marks are left. Then I go back down the edge on each side with the file 45degrees to the edge to take off the sharp burr. After that, I use a 90 degree die grinder with a 1″ scotchbrite wheel that has already been used many times for edge deburring such that it has a number of grooves in it. When I go down the length of the edge with the small wheel, the groove in it finalizes an almost perfectly smooth radius on the edge.
I tried a number of things to scuff the tank skins for the proseal (scotchbrite pad, 200 grit sandpaper, blue aluminum oxide wheel from home depot). The last thing that I tried that worked the best was a 2″ scotchbrite rolo disk on 90 degree die grinder. This is what I generally use to buff out scratches with a finer disk. Note that I scuffed the tank skins before I dimpled them. It would have been a real mistake to dimple then scuff as the action of getting a good course scuff would have damaged the dimples. I’m also using special tank dimple dies here that are a little deeper to accommodate the proseal.
Today I scrubbed all of the ribs (LE and tank), tank stiffeners, and tank skins with soap and water. While that stuff was drying, I bounced around and did a few other things. I got all of the tops of the wing spars machine countersunk for the skin dimples and deburred one side of the main ribs on both wings. I’m still liking building both wings at the same time. This evening I prepared both tank skins for back riveting the stiffeners and fuel filler flange tomorrow. While I was doing this, Tanya acid etched the LE ribs in preparation for alodining tomorrow and priming on Sunday.
So, as this weekend of building starts, I’m hoping by Monday we’ll be ready to start riveting the outboard leading edge ribs to the skins (once that is done, I’ll do landing light installations) and have at least a few tank ribs prosealed and riveted in place. This would put us on track to be about ready to close up both tanks by next weekend. We’ll see.
