Whoa. Awesome day today. Read on…
So in order to start actually skinning the wing, I need to make sure all the skeleton finishing items are completed (deburr and dimple (or countersink) the main spar, ribs, and rear spar).
To get the countersinking on the main spar, I needed to pull the right tank back off, which was fine, because I’d like to have it in the driveway for the leak check, so I can put soapy water on it and then spray it down with the hose.
So, here’s the tank off. (It’s a beautiful day out, today…98°F, heat index of 102°F…and it’s NOT a dry heat.)
Right tank back in the cradle for hopefully the last time.
While it’s off, let’s get the main spar countersunk.
My countersink cage was already dialed in, so I banged this out in no time.
Almost forgot. Some balloons and a transfer pump from Harbor Freight. (Why not a bicycle pump? Because I don’t have a bicycle, and I figured I could use a transfer pump for other tasks later.)
Don't worry, it's got a Schroeder valve fitting.
Just for kicks, I hooked up a red tube to the vent fitting and hooked the pump up.
WE HAVE INFLATION!
And then fairly subsequent deflation. Boo. Back to this in a minute.
Moving on, I needed to get the rest of the leading edge rivets in. I grapped some more MSP-4X blind rivets and got to work on the outboard two ribs.
If you don’t insert the rivet all the way, you can close the rivet puller and put the lock on it, then it’s easy to feed through the rib holes and find the holes for the rivets.
If you look closely, you can see the rivet in the end of the puller.
Now I can stick the whole thing in there and place the rivet, undo the lock, and slide the puller down the shank of the rivet and start squeezing.
After an hour or so, I had the ribs I could reach from the outboard edge of the wing, and the two ribs I could reach from the inboard side (the tank’s off, remember?).
I had a hell of a time getting the middle rib, though, but it ended up working out okay from the aft side of the spar.
Here are the outer two ribs.
Okay, since we had a little deflation, the girlfriend came out with a bottle of soapy water, I filled up the tank, and she sprayed for leaks.
For once, those aren't my toes. (Look how trigger-happy she is! Ready to spray!)
We found TWO leaks.
(OMG OMG OMG OMG NOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO!)
Gotcha. They were at my weak-ass vent to balloon line attachment and on the feed line cap supplied with the test kit. (Oh, and many people have leaks around the fuel cap. I didn’t. I guess the deluxe caps seal pretty well.)
You can see the bubbles you're looking for on the right side of the blue AN4- fitting.
For kicks, we blew up the balloon again and checked again.
Then, for some reason, here are some more leading edge pictures…. this is the outboard-most ribs.
Sweet. (Although I need to check the spar flange rivet where it meets the rib flange. That doesn't look flush.
Okay, back to my two pseudo-leaks. I redid my balloon line with electrical tape and tightened the feed line cap.
Blew up the balloon…
Checked back in four hours…
LEAK FREE RIGHT TANK!!!!!!
Wuhoo!
Of course, I threw the tank up and put in all the screws and z-bracket bolts, just to figure out that I forgot to attach wires for the float fuel sender (out of reach once the tank’s on the spar.)
So, I wasted an hour putting those in and taking them back out. Bummer.
3.0 hours today, although it didn’t feel that long. 1.5 on the leading edge and spar, 1.5 on the tanks.
Andrew's RV-7 Build Log 