WINGS

Section 18 Fuel Tanks

November 1, 2004

Page 18-8   Page 18-8 PDF

Note:  Since I am about ready to close up the tank I wanted to check to find any obvious leaks before putting the baffle in. I took a small flashlight and put in the the tank bays and put the baffle in place. I took it into a very dark room and I could see the light shining through in a couple of small holes on the rib to skin. I put a blob on them and hope all the holes are sealed.

Got all the rivet organized that I am going to use. Soaked them in MEK to clean them.

Step 1: Apply sealant to the T-1001-l Fuel Tank Skin from the T-1002 Tank Baffle rivet holes forward. Upon installation  the tank baffle acts as a squeegee and the bead of sealant will be pushed ahead as the baffle is moved forward. Use a maximum of 3/16" bead of sealant; too much and the thickness can start to build-up making the tank difficult to install on the wing. Note: Thought I would mask the 3/16" off and then smear the sealant on and pull the tape before installing the baffle

Step 1A:Used a cake decorator tube to apply sealant. It seemed to work pretty well and it was nice to have the mess contained. When you need some even if you apply with a stick, it is easy to squeeze some out on the stick and you have good control of it.

Put a bead of sealant along the inside edge of the flange on each end rib, Put a heavy blob of sealant where each corner of the baffle will meet the end ribs (this is one of the most common locations for leaks).

Put a thin smear of sealant around each of the rivet holes on the back flanges of the tank ribs.

With the tank sitting in the Leading Edge Assembly cradle, install the rear baffle by dropping it straight down on the rear flanges of the ribs as shown in Figure

Put a Cleco in every hole of the tank skin to baffle joint. After clecoing, inspect the skin to see if it is pillowed-out between Clecos. The contact surface of the tank baffle flange may require pressure to force out excess sealant. The easiest method to squeeze out the excess is to apply a c-clamp or strong spring clamp between each set of rivets. If unsure, clamp the flange in couple of spot and see if it makes a difference.

Step 2:   Install the rivets attaching the T-1002 Tank Baffle to the T-1003 and T-1004 Fuel Tank Rib flanges as shown in Figure 1. Twirl the closed end blind rivets in sealant just before installation. The solid rivets that are installed through the end ribs need not be twirled in sealant.

Apply a thin smear of sealant over each hole for mounting the T-1012 Tank Attach Zee's. Cleco the tank attach zee's in place. Check for proper tank attach zee orientation as shown in Figure 1.

Install the tank attach zee to tank baffle to rib flange rivets as shown in Figure 1. Twirl the closed-end blind rivets in sealant just before installation. The solid rivets that are installed through the end ribs not not be twirled in sealant.

It is recommended to use a cut-off rubber glove or similar cover over the open end of the vent line. This is to keep debris and/or nesting insect from blocking the vent lines.

Step 5: Install the tank to the spar and leading edge sub-assembly as shown in Figure 2. Note: I am going to install the tank and let it cure for awhile before testing it. Picture shows the Schrader valve that is used to put air in the tank. Kit can be ordered from Van's for testing, see next step. Even though the tank needs to be removed again to do remaining rivets on the flange, I put all the screws and attach hardware on and found a couple of bad nutplates. Since the tank will come off again they should be easy to replace.

Found a bad nut plate on tank attach