Category: Fuel Tanks

April 18, 2011 – After a little finesse on the outboard end of each tank, I installed them. I’m sure they’ll have to come off again at some point, but now things look pretty aircrafty.

You’ll recall that I had some pillowing of the skin between the screws where the tak joins the fixed leading edge:

After a little lovin’ here’s roughly the same spot now:

I’m pretty satisfied with this unless I see something a whole lot better on other airplanes.

Here’s the left wing with the top skins clecoed on:

Riveting the top skins will be the next big project. In the absence of help, I want to do things like paint and install the landing light brackets; things like that.

Time: 2:10

April 18, 2011 – Last Thursday I found one more rivet for the left tank baffle that was leaking. I removed the rivet and did the shop-vac thing again. I went to Minneapolis over the weekend with my son to check out a school, and got back last night. This morning was the leak check, and I’m happy. I have a couple things to do around the house, and I’m going to try to check the fit of the tank later today. I hand-worked the skin between the screw holes on the outboard end. We’ll see how that goes. If it works out, I’ll remove the right tank and do the same thing.

Time: :45

April 13, 2011 – My right tank is complete and (maybe permanently) in place!

I went back to Addison and leak checked the leaks that I repaired last night. Here’s something: the trick with the shop-vac worked! That was in the right tank and it all checked out. The left tank, however, had another leak. It was the one in the previous post with the leak in the corner at the baffle/rib/skin joint. That one checked out, but I found another at about the center of that same end at the attach for the end z-angle. It may have been that the one leak yesterday was so big that other leaks didn’t show up.

So I brought everything home, including the regulator setup. I did the shop-vac thing again. The sealant hasn’t set up yet, and I’ll be out of pocket for the next few days, so things should be nice and dry by the time I get back.

I installed the wiring for the fuel float sender in the right tank. I had to do this now because the float is attached to the baffle and will be inaccessible when the tank is installed.

Then I mounted the right tank. Screws and bolts line up and go right in, and everything looks aircrafty.

One issue I see, and this appears to be very common, is that I have slight pillowing between the screws at the tank/leading edge junction.

I’ll research and address this later. It does go all the way around the tank edge.

I also clecoed the top skins to the left wing in preparation for their installation.

Time: 2:40

April 12, 2011 – Today I leak-checked the tanks. I took the tanks to Addison where my friend Kato had some of the equipment to do the job.

We hooked up the regulator and gauge to the vent fitting.

We put 2 PSI to the tanks and sprayed soapy water.

We found three leaks. Two were rivets, one of which is for the baffle (no sweat there). The other is a rib fastener just forward of the baffle.

The other leak was in the other tank, and was a bit bigger. Turns out I left a hole in the corner between the outboard rib, the baffle and the skin.

That was easy to fix because luckily, it is in the same bay as the fuel filler point. I put sealant on the outside, and I taped a long q-yip to a long screwdriver, put some sealant on the end, and reached in and applied it in the corner on the inside.

I brought the tanks home, and attempted a poor man’s fix on the internal rivet. I placed the hose of my shop-vac in the filler hole, and it fit perfectly. I held the hose there tightly while I applied some thinned sealant to the outside of the rivet. We’ll see if it did the job. The rivet leaks were both very small.

Time: 2:15

April 11, 2011 – As I stated in an earlier post, I didn’t really like how the baffle rivets looked in the left tank. So I’ve replaced them all. I removed about 10 rivets at a time, recountersunk the holes, and reinstalled the rivets. It’s much cleaner and smoother now.

Tomorrow I plan to leak check the tanks. Fingers crossed!

Time 1:50

April 6, 2011 – Not much to tell today. I just installed the access panels for both tanks, and sealed them in place. I’m hoping to try to leak check the tanks next week.

Time: :45

April 5, 2011 – In preparation for closing of the right tank, I had to install the flop tube. I had to clean up the 9/16″ hole where the fitting passes through the inboard rib and the T-405 and T-410. I ran a reamer through there by hand.

I then put sealant on the fitting where it goes through the rib, and tightened the jam nut on the outside, making sure the tube rested in the anti-rotation bracket.

I placed the tank in the cradle and cleaned the mating surfaces with acetone.

Shown below are the tank, and then the baffle with the float sender installed.

I did adjust my countersink a few thousandths deeper and ran over all the baffle holes through the skin, because my left tank rivets sat a little proud of the skin. These are much better.

Time: 2:30

April 3, 2011 – After cleaning the sealant from the rivets for the baffle on the left tank, I found that many of them were sitting a bit proud of the surface. Since I never change the depth of my countersink, I can only assume that the difference is the sealant.

I went down both rows and gave the rivets some love with the gun and a light bar. They’re better. Not baby-bottom smooth, but better. To fix the problem for the right tank, I did adjust my countersink.

Time: :25

March 30, 2011 – Not much today, I just installed the inboard and outboard z-angles for the left tank. When I finished with that I also installed the rivets for the right leading edge.

Time: :15

March 29, 2011 – After a little bit of clean-up work on both tanks, I decided to bite the bullet and close the left tank. I mixed up the sealant and put a bead along the rivet lines and the aft edges of the ribs, then I put the baffle in place and clecoed it to death.

I installed the upper and lower pop rivets in each rib, then I sealed and clecoed the z-angles in place, making sure they were oriented correctly. The pop rivets were installed wet, by dipping them in the sealant.

To install these I had to modify my trusty pop riveter that I bought when I started my airline career 23 years ago. Kinda hated to do it.

Just for good measure, I cap-sealed the pop-rivets.

Then I used a squeezer to install all the upper and lower skin rivets and the -4 button-head rivets on the upper and lower ends of the inboard and outboard ribs. I still need to install the z-angles on those ribs.

Time: 4:20

March 18, 2011 – I took a few minutes to address the problem with the fuel pickup tube I discussed in the previous post.

After discussing the problem with someone else, I decided to use a finger screen; a solution I always preferred over the sawed inlet holes per the plans. I cut the tube off at the last inlet hole that I had made. I then cut the fitting off of a finger screen that was donated to the cause.

I located the screen with the access panel installed, then made a mark through the screen onto the tube. I drilled a hole laterally for .020 safety wire, and slid the wire through the screen and the tube.

I took the access panel out, and wrapped the safety wire in opposite directions, as tightly as I could.

I coated the joined area between the tube and the screen with sealant.

With the extra sealant, I installed the float in the panel, and put it all in place.

Time: :40

March 16, 2011 – Today I installed the left tank fuel sender and the T-405 attach angle.

The sender float wire gets bent to reach its full up and down travel within the tank. I used the measurements provided by Van’s on the added sheet that came with the kit. I bent the center angle at 3 1/4″, and then the short 3/4″ section that goes into the sender. That bend was also 3 1/4″ from the center bend. I slid it into the sender and checked travel. I had to adjust the bend just a hair because the float didn’t quite reach the bottom of the tank. Then it was time to measure resistance through the sender. My old faithful meter decided to give it up, so I borrowed one from a friend. The readings were just about what they needed to be.

I also installed the T-405 attach angle and the T-410 doubler on the inside of the inboard rib leading edge. Kinda messy, but not too bad.

I do have to slightly rework the left tank fuel pickup tube. I made it too long, so it will not allow the baffle plate to be installed. I cut it to shorten it, but I’m not sure it will withstand recrimping the end. I may have to make a new one.

Time: 2:40

March 15, 2011 – Since the center ribs for the left tank got done in the last post, I installed some of the necessary items to eventually prepare for closing.

I installed the T-410 doublers on the outboard ribs for both tanks.

I installed the outboard rib in the left tank.

I then installed the snap bushings, the fuel vent line and the fitting in the inboard rib.

I then installed the inboard rib for the left tank. I still have to install the T-410 doubler and the T-405 mount bracket at the leading edge.

Time: 4:25