Final tank prep - 3.5 hours

Its funny when you say that you are ready to proseal but really there is still much to do. There is lots of holes to debur. This gets to be a long process. I managed to do the left skin and after have very sore fingers!

I need to go over each area where proseal makes contact with a nylon wheel brush. I used the air drill but soon found that the compressor just couldn't keep up and was running quite hot and the air was getting moist (the air dryer couldn't keep up). So I ditched the pneumatic drill in favor of the electric drill.

Takes a bit of getting used to to ensure good coverage and straight lines but I was successful in the end. The first pass is made, and then a second pass is done to form a criss-cross pattern. The key is to try to keep your lines/passes straight, while applying just enough pressure to score the aluminum but not dig too deep. Its easy to maintain the right pressure, but a little more tricky to hold it straight.
Going slow helps a lot. 


I managed to prep the skins of both tanks.

Right tank skin prep - 2 hours

Still battling a lack of desire to build (now that spring is here and there is so much outside work to do), I managed to get a couple of hours of work in on the right tank skin. First order of business is to de-vinyl the outside tank. Then, I deburred. Once I was happy with all of that. I wiped down everything with MEK.

Its getting late and I'm yawning.

Finishing new anti-hangup bracket - 1 hour

Managing to find a little bit of desire to build today, I managed to cleco up the other fuel tank and fabricate the new anti-hangup bracket. Much easier this go around as I already have the paper template drawn out and the 1/2" wide material.

Creating a new anti-hangup braket - 3 hours

I am zapped of all energy from the weekend. Had a house party on Saturday, and it was three days of prep and cooking, followed by a late evening.

I managed to gather enough strength to began fabrication on another anti-hangup bracket. I had to cut more 0.025" material at 1/2" thick. I cut a paper template and tried again. This time,Ii referenced another build log and twisted the bracket so that it ended up slightly back from the original position.



This way is a bit more challenging to fit but I made it work with using the holes that I had drilled before. Just really had to go slow and work at it. No quick work here. The result was excellent.

Only one small item that I noticed. At one point of the fittings, it had a tenancy to grab a little on the stiffener. I'll have to take a better look at this with Mike.

Thats enough for today. I'm spent!

Testing the inner anti-hangup - 1 hour

When looking over all the build log photo's of the fuel tanks, I noticed that most folks didn't have a inner anti-hangup bracket like mine. It occurred to me that I did not test the full movement of the fuel pickup. It was bothering me, to I re-cleco'd the assembly just to check. Well wouldn't you know. There was an issue with the anti-hangup bracket. At one point the sharp edge of the bracket makes contact with the rubber ring on the pick up. Well...My fear was realized. Back to the drawing board.


I will have to create another setup.

Setting the countersink depth for the tank filler flange - 1 hour

One small job to do is to countersink the tank filler flange. Not much to it other than to start the tedious process of setting the countersink cage depth. I had dimpled a piece of scrap with the tank dimple dies and then I would compare them with the countersink depth. I took some time, but I am finally at a point where I am happy with the depth.

Final fitting fuel sender and completed Left tank fabrication - 5 hours

I had planned to set the fuel float sender 4" outboard of the 2nd rib, however it looked just a bit too far out. When referencing the plans Van's locates it quite close to rib #2. I made the choice to play the center of the hole 3.25" outboard of rib #2 center line.

Now cutting the 1.5" diameter hole caused a bit of head scratching. I had asked my buddy Mike what he thought and he suggested a hole saw but cut in reverse rotation (forward rotation would chew up the aluminum). I didn't think this was too bad an idea. I had decided to cut a piece of oak with the 1.5" hole saw to help as a guide...that worked really well.


I was left with a nice clean hole. I used the small diameter 3m wheel and then a dremmel with scrotchbrite to smooth the edge. I then fitted the stiffener ring that I had fabricated and centered it on the hole. I checked twice to ensure correct orientation as there is only one way that the senders will fit. One I was happy with how it all lined up I drilled all of the holes for the nutplates.


I cleco'd the sender to the rear baffle and then set it on the tankoffset by one bay so the sender was sitting in the first bay. This way I can check max and min travel.

Just like before in the mock up. The travel to the top of the tank is excellent. A little more than 1.8" clearance. But on the low (or empty tank travel) the float holder wire contacts the tank stiffner.


Noticing that the contact is made at almost the end of the empty tank travel, I decided to cut a portion of the float wire with side cutters and smooth it out on the 3M wheel.

Now I have full travel with good clearance from the stiffener. The right tank is now ready to proseal. Time to finish the left tank. With exactly the same procedure as the right tank, I finished fabriction of the left tank.





I started to counter sink the fuel flanges for the tank die dimple. once I was happy with my depth I had stopped for the night. Then I received a text from Darin building the RV-14. Did I see the latest Service Bulletin for the wing? My heart stopped. I ran over to the laptop and looked it up. Soon a realized that I was in the clear. I had not reached that part yet on the rear spar and can easily incorporate the newly recommended stiffener for the aileron hinge.    

Next stop proseal!!!