RV7-Factory

Inboard Rib Penetrations and Other Tasks

With the work completed Monday, I was essentially ready to take care of the last of the little sealant tasks to be done before the “big smears” are to start.

Last night I had CAP meetings and then ended up hanging out at the airport, helping a friend rivet a bulkhead on a Harmon Rocket. Once that was done it was too late to start any sealing in my shop.

So tonight, I devised a plan of attack to maximize my success and knock out these little tasks. I started by prepping the T-410’s for the outboard end ribs. The manual clearly warns you about installing these on the inboard ribs, but the clearance on the outboard is just fine. Riveting them now is far easier. I scuffed them up and cleaned them off with MEK. I then grabbed 12 AN470AD4-5’s and soaked them in MEK for a bit.

I then loaded all the AN fittings and spacers into a jar of MEK to give them a good cleaning. I wiped both the inboard and outboard ribs down and from that point on, did not touch any parts without gloves on.

I grabbed a 6oz cartridge of ProSeal and mixed away. I first sealed the T-410s to the outboard ribs. I 100% clecoed them on and set them to the side for a bit to allow them to squeeze out. Then I went to sealing the fittings and spacers to the inboard ribs. I first put a thin layer of sealant on the shoulder of the AN fittings, inserted them into their locations and then, after smearing the backside of the spacer with a coat of ProSeal, placed it over the fitting. I then put a small fillet at the fitting on the top of the spacer and then threaded the nut on. This caused a thin gasket of ProSeal to squeeze out from under the nut. I torqued the nut to spec and then repeated this process for the other three fittings.

Next up were the BNC fittings for the fuel senders. I was tempted to put the same thin layer on the shoulder, but the barrel of the BNC needs good continuity between it and the tank. I decided to insert them dry, then tighten the nut, and then seal them good from the backside. With a good “Hershey Kiss” of sealant, it should not leak. Once installed, I did just that, gave it a healthy covering to extend well over the wire and solder joint. It really does look like a black “Hershey Kiss” when you are done.

Once the fittings and BNC’s were in, I went back to the outboard ribs and squeezed the rivets. I then proceeded to “mill” all the sealant. I made nice fillets around the edges of the T-410’s, cleaned off any over done squeeze out, and then covered each shop head with sealant. The manufactured heads will be covered once the rib is attached to the skin, so I cleaned the outside of the rib completely. I then went back to all the fittings and created nice fillets around all the edges of the spacers and nuts. Once that was done, they were nearly covered completely, so I just decided to finish it off. Should not leak here.

Lastly, I hit the outboard Capacitance Fuel Sender plates, where the wire/ring terminal are bolted on, with sealant on the bolt/screw/terminal/nut, as well as sealing off were the wire enters the ring terminal. I think the purpose is for providing good strain relief for the wire. Some say it is to keep fuel from wicking into the strands of the wire. Either way, mission accomplished.

Once all that was done, I went back and cleaned up all the strings of sealant left on parts, cleaned up my tools, and called it a night. These parts will sit for some time while I do the rest of the tasks needed on the tanks, so the sealant should be well cured by the time I mess with them.

Next up…Tank Assembly!

Parts Prepped and Ready for Sealant

My wife and kiddo’s took off today for the week to play crew support for a scout hiking trip in southern Utah. She left VERY early. Since there was no way I was going to go back to sleep, I headed into the office. I figured I would get the work day knocked out and head to my empty home early. While the “get home early” never happened, I did get out to the shop for a bit.

I prepped the inboard rib penetration spots for sealant. I first scuffed all the locations where the vent and vapor return fittings, and fuel sender connectors would go. Then I cleaned up the spacers by deburring the edges and scuffed the faces.

Lastly, I cleaned up the Capacitance Fuel Probe BNC’s and wires to remove greases, finger slime, and other debris. Once that was done…I was ready for sealant. Not tonight however.

Proof for the FAA.

OK…so I hate ProSeal. I know I shouldn’t, but I do. I despise the sticky, gooey, snot like stuff. That said, I need to get moving on the plane again. A fellow builder/owner has been hassling me (actually giving good moral support) to get going again as well. Does not help that he let me borrow his sealant gun back in November and I have been holding it captive. We chatted this week again and he darn near pushed me into the shop verbally right then. Thanks Todd!

This weekend had a few items on the “To-DO” list. First, we planned to go hiking as a family EARLY Saturday AM. Apparently the powers that be decided otherwise as the regulator for the drivers side window in our family hauler decided to catastrophically fail Friday night. My Saturday morning turned into a “can I find one” mission and if so, “can I change it out” followup. Fortunately, the dealer did have one, and as much as it pains me to pay more for genuine Honda parts and their associated price, they were local, and I could get the van back in service quick. You got to love Honda engineering. They really seem to think things through from a build and repair standpoint. It was actually a pleasant repair all said and done. I was happy to have the family assault vehicle back in shape.

So with that rewrite of my list, I decided to take a nap, then head out to the shop and see what I could get done. Since buying my original can of B2 ProSeal, it has LONG since expired. My friend Todd had some 1 oz. B2 Semco cartridges he gave me when he lent me his gun. They too had expired a little while ago, but in conversation with him, he said if they mixed up smooth, they should be OK. Did not hurt that they were stored in a cold shop for the last few months. He also gave me some newer 2.5 oz. sized B 1/2 type as well this week. Can you see a trend? Todd really wanted me to make some progress. I also learned that I could purchase some 6 oz. B 1/2 or B2 tubes locally for a decent price.

There has been some debate around the mix as you go or Semco cartridge routes. Both certainly have their advantages and disadvantages. I won’t rehash it here unless asked, but I found that I REALLY liked the gun/cartridge route this time, despite tossing some sealant once I ran out of time. The gun really lets you control where the sealant is going and eliminates the headache of measuring out the parts and making a mess mixing it. It costs a little more to go the gun route, but the convenience seemed very worth it. I think I will borrow the gun from Todd a few more times.

Right Tank Stiffeners Attached

First up were the stiffeners on the bottom of the tank. I masked off the areas with electrical tape after cleaning all the stiffeners and skin with MEK.  I then shot each stiffener with a bead of sealant, smeared it over the whole surface, and then clecoed each in place. I waited a few minutes for squeeze out, then back riveted each and formed the fillets. I used the sealant gun to put a dab over each shop head to eliminate any path for fuel to leak. This took about an hour. I used the 1 oz. B2 tubes that were a little old. They mixed well and the sealant came out nice and smooth. (Update, they cured fine too.)

Right Tank Sump Flange

I then moved on to the sump flange. By then my flying bud, Matt had arrived to kill his boredom. He helped keep my mind off my dislike for the sealant. I smeared the faying surface and clecoed it on. After 5 minutes, came back and was able to use my squeezer and install all these rivets. The shot above is after some serious cleanup. I got a little in the threads of the flange, but I think I can clean it out with a tap or rag later.

This Should (Better Not) Leak!

Last, or so I thought, was the filler neck and vent line clip. As you can see, I got a little carried away with the sealant here. I had plenty in the tube and was getting short on tasks I had planned out to accomplish. Needless to say, it should not leak, at least not here. I was able to get the four most outboard rivets with my squeezer, but the rest I back riveted in place one at a time.

Right Tank Filler Neck and Cap from the Outside

Here you can see the flange/cap from the outside. Turned out OK. I have one rivet that appears to be slightly high, but I will likely shave it down. Replacing it would be very difficult now that I have super sealed it. There is a nice bead of sealant around the opening in the skin and each rivet. The deluxe caps sure look nice.

Outboard Tooling Hole Filled and Sealed Inside

At this point, I started to clean up stuff. As I was looking around, I remembered that I had some AN470AD6 rivets (again from Todd) that I could use to plug the tooling holes in the outboard ribs. These are big suckers and my squeezer just barely did the job. I put the manufactured head on the inside of the tank to give it the best bearing surface area contact. Once I got it smashed in place, I coated both sides with sealant.

Outboard Tooling Hole Sealed

Here is the outside of the same. Sealed and covered. Takes care of that hole.

The time was spent, I was tired. So I cleaned up, tossed all the sealant covered rags, gloves, cartridges, and friends out and closed up shop. I will let this sit for a bit to cure and then likely hit the inboard rib penetrations/fittings with sealant. Todd told me he would help me with sealing/riveting the ribs, so I need to get everything else done so he is not held up by my feet dragging. I will get through these tanks eventually.