Continued Sealing Left Tank

Today when we got to the airport Dad and I saw that old Hangar 4 was being torn down. This wasn't a surprise because there's been talk about it going down for about a year now but it's sad to see. It was 1 of 2 remaining historic hangars on the airport. There were originally 5 but they were lost to fires along with some beautiful aircraft. Insurance companys don't like insuring wooden hangars anymore I guess so it had to go.

Well last time at the hangar Dad and I got a couple of ribs riveted in the left tank and today we continued the tedious process. But before we got messy with sealant we were ready for a new little project. We cut some AWG 18 wire to 15" and soldered the BNC connectors to them. These will connect the capacative fuel senders to a fuel transducer inside the fuselage. It was a short project but fun, and good for a change of pace! I haven't soldered for about five years but today Dad said my connections turned out perfectly. We still have to do the piece that interconnects the two plates inside each tank but we still need to obtain a proper wire crimper.

Once our soldering was complete we moved back into sealing some ribs. Not too much to report on these, we did the same process as the past two ribs. We weren't able to get more done but we're still happy with our 2-ribs-a-day progress. They're turning out quite nicely too if I do say so myself.

More Fuel Tank Sealing

Well today Dad and I delved into sealing ribs in the left fuel tank. In our previous work session we got the stiffeners, fuel tank filler, and fuel drain sealed and riveted into the left tank. Today we wanted to catch the right tank up to this stage so we got to work on that. While our rivets soaked in an M.E.K. bath in our Starbucks Expresso bottle we got prepared to rivet. We followed the same procedures that we used on the left tank except for one exception. Instead of using -4 lenght rivets for the drain, we went down to -3.5s. Reason for this is that the -4s were too long and tended to "lay over". We're not going to worry about this though since the drain is a non structural component and it's battered up with a good amount of sealant (which is also a strong adhesive).

Once we caught the right tank up we moved on to riveting the interior ribs for the left tank. This proved to be more difficult than the stiffeners since you're working in a more confined area. We put the skin in our cradle and clecoed in all of the ribs minus the one that we would be working on. This is recommended so the fuel tank stays straight and maintains its shape. We mixed up our sealant and got to smearing! Before we did though we scored the flange (and previously the skin) with emory cloth to provide a prime adhesion surface, once we were done with this we made sure to put a thick layer of sealant along the whole flange of the rib. Once it had a good layer we slid it in and put a cleco in every hole to pull it tight. Our riveting process had us rivet the front half of the bottom of the skin, then the full row of rivets on the top, and then finish the remaing half of bottom rivets. Van's tells you to rivet from front to back in order to eliminate slack.

We were able to finish two ribs today which made us happy! They are definitely a lot of work and we shall get back to work on Thursday.

Fuel Tank Sealing

Well today after work Dad and I thought we'd begin to tackle the job of sealing the fuel tanks. Needless to say we've been dreading this task for a while. Tank sealant isn't exactly the easiest or cleanest stuff to work with. Before we began to mix up some sealant we put the whole left tank together for a dry fit (minus the vent line) to see how everything went together and to make sure if there was enough clearance between the capacative senders and the stiffeners. Everything looked good so, Houston, we have clearance! Once we were satisfied that everything would go together smoothly we began to scuff the rivet lines with medium grit Emory cloth. We did this to promote better adhesion since the rough surface creates more surface area. After this we used Coleman lantern fuel to clean the tanks off. This stuff works pretty good, it takes up all of the oils and leaves no residue. It doesn't smell too bad either like M.E.K. or anything. After we had the skins cleaned up and our tools all sorted and prepared we started to mix the tank sealant. We used our small digital scale and measured the stuff out cup by cup. It's mixed in a 10:1 ratio and it took a couple of attempts to get comfortable with working with this stuff. It's like tar. Extremely thick tar. After mixing for a couple minutes the black hardner was mixed with the white base and we were left with a dark grey substance. We followed the tapes instruction and had the stiffener rivets taped in place (we did four stiffeners at a time) then we smeared the stuff in nice thick layers on each stiffener and set it in place. Then we backriveted them and went back over the shop heads to make sure that we had a good seal. We repeated this a few times and had all of the stiffeners in place and set. After the stiffners we put the fuel drain in place and set its six rivets. This made a mess because sealant oozes out of the holes from both sides and gets all over your squeezer. Have an old rag soaked with laquer thinner to do some quick clean up for your tools and anything else you might need. After the fuel drain we moved to the fuel filler flange and smeared a bunch of sealant on it. We put it in place and put the vent clip on the very front rivet. We got these rivets bucked and decided that's all the time we had for the RV tonight. We cleaned up all the excess sealant with a rag and some laquer thinner and are now just letting it cure! I'm glad we only did one tank tonight. It gave us a chance to get used to working with the sealant and didn't overwhelm us. In a couple of days we'll be back out to do the right side! Also, sorry no pictures tonight. We left the camera at the house.

Fuel Tank Prep

Today before work Dad and I thought we would prepare the fuel tanks for their sealing. So we did just that. I still have a couple of questions on the capacative senders and the vent line but we still got a lot done today. We had already drilled the filler caps to the tanks a few days ago, but that's all we had done to them. We took them off and I got to countersinking them. While I did that Dad taped in some rivets so we could back dimple all of the holes that needed it. Once we had the filler all in place we moved on to the drain sumps. These were pretty straight forward. I just used a square and drew a line through them from front to back and we lined the holes on the drain up with the line. No one will ever see them, but at least they're symetrical! While we were on a roll we wanted to keep going and get as much done as possible. We dimpled the perimeter screw attach holes with our squeezer and they turned out great (Van's says you get better results with a C-frame but I don't know how.) Since I had to work at 3 today, we left enough time for us to watch a Fuel Tank Sealing tape. The thing was shot in the early 90's most likely but hey, it's still relevant and we both learned a lot! After that I had to leave for work and Dad got to work on notching out the vent line snap bushings, he did a nice job on them and that was all we were able to get done today but we're happy!

Aileron Work!

Wow, what a productive today. We started with a pile of primed parts and ended up with completed ailerons! Two of them!

After some breakfast and coffee at the airport cafe, we headed over to the hangar. To our surprise our hangar partner's car was there and his airplane was gone. Not too common that that happens, but hey, more hangar to us!

Since we hadn't gotten too much work done on our poor RV lately we really wanted to make some progress today. We were having some problems yesterday riveting the nose ribs to the aileron spars, our rivets kept on folding over on the shop end side. FRUSTRATING! But today we decided we would try as many solutions as we could until we found one that worked. Previously we had been squeezing them, which never gave us problems before, but the rivets that Van's calls out seemed a little long. We trimmed them and tried that, no luck. After a few times drilling them out from the shop end side (no access to the manufactured head) our circular holes had become quite oblonged. Not an ideal shape for a solid rivet to be set in, so we decided we would make a couple of plates to cover the holes. This worked previously on other parts of the project, but this time we set one rivet and the plate just folded up because the rivet sucked it into the hole a bit. Our only other option was to use some strong blind rivets. We drilled the holes out to 5/32" and put those suckers in. They filled up the hole and made the part very strong. Finally something worked!

We continued on and riveted the leading edge skin to the trailing edge skin and the spar. Initially this proved to be tricky, and a little painful. It took a while to figure out how to fit your hand between the bottom of the aft skin and the spar to get a bucking bar in but we finally devised a way to get it done. Dad held the skin on its trailing edge and I shot and bucked the rivets. Once this was done we riveted the nose ribs to the top half of the leading edge skin and then the main ribs, once these are done the assembly gets flipped over and weighted down. The counterbalance weight gets blind riveted to the skin and the ribs get finished being riveted to the skin. Once everything else is done you finish it by "closing" it with blind rivets along the bottom of the spar. Once the left flap was done we moved onto the right and banged that out. Only this time we had better luck with squeezing the larger rivets and we had a better understanding of how we wanted to do things!

If only all days at the hangar were like this, productivity feels great!

Busy, with work other than RV work.

Unfortunately I don't have too much new to post. I've been busy studying for the CFI certificate and have been devoting most of my time to work and that. Though we have completed the flaps, which was movivating! They look great and they feel bulletproof. Our right flap ended up having a 3/32" twist in it, but that's so nominal we can't imagine it having any noticeable adverse effects. Tomorrow Dad and I are both off and we hope to get some work done on the fuel tanks, though today after flying the 150 for a couple of hours I noticed a large accumulation of oil on the belly. The dipstick didn't show a loss of oil so until we check it out, it remains a mystery where it is coming from. Nice weather is forecasted so we'll see how it goes.

Fuel Tank End Ribs

Today Dad and I figured we would get cracking on the fuel tank pick up tubes. In the last post I noted that we would have to make a new hole for the flop tube, which would be located at the front of the inboard rib, and not on the access plate. We had already cut out the hole for the standard pick up tube in the plate and instead of making a cover for the hole, Dad fabricated a beautiful brand new one out of some .060" stock that we had. It looks great!

The hole up for the flop tube was a multi step process. Our unibit only goes up to 1/2" and the fitting was significantly bigger (I can't remember the diameter) so we used ours, and then finished the hole with our friends larger unibit. We had to do this for the rib, the angle bracket, and the backing plate. There is a proper position for the fitting noted in the plans, but we didn't see this until after we had cut the hole. Lucky us we were within 1/16 of an inch!

After we got the hole done, I had to head to work but Dad stayed at the hangar and continued to make some progress. He was able to cut an anti-rotation bracket for the right tank pick up and he also made the trap door that fits over the corner hole on the interior rib. After that he made the bracket that goes over the left side inspection plate so the flop tube doesn't get hung up. We still have the othe one to make that fits inside the bay.

All in all, today was a pretty productive day!