Lynn's RV-7 Build

Good progress tonight! I wrapped up a few miscellaneous things that needed to be done before riveting the inboard outer rib. Here is the time lapse:

The first thing I did was to test fit all the accessories and fittings on the inner rib to make sure I had everything I needed in the proper places.  I also wanted to think through how I’d best complete the sealing work since there is some complex parts with the flop tube.  Ultimately, I decided I’d go ahead. and seal the fittings for the vent and tank return lines, the BNC connector for the capacitive senders, the anti-rotation bracket for the flop tube, and the anti-hangup brackets thats on the access plate. That way I could most effeciently use my sealant, and leave the other items (all the stuff at the nose of the rib) for when I am ready to rivet them in place.

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Next, I scuffed all the pieces that were getting sealant tonight, and cleaned everything nice and well with MEK.  Then got my parts and work area organized to start the sealant work. Once thing I needed to go ahead and do, was to torque the flop tube down to its elbow fitting, safety wire it and make sure the nut shoulders fit into the anti-rotation bracket.  This is my first time safety wiring, but I watched some videos and read a little.  I think it turned out pretty nice for a first timer…….if you don’t count all the scrap from the other dozen times it didn’t turn out nice!!! HA.

The failed attempts:

It’s orientation is such that the safety wire is actually pulling the nut tighter on its threads. You have to really be careful you don’t have the safety wire pulling on the nut and rotating it LOOSE.  Anyways, that was a fun experiment. Now its time to seal! I mixed up 20 grams for this session, which was about 5 grams too much.  Close enough I guess.  Here is the list of parts I will be sealing.  Notice I went ahead and screwed the wire terminal on the capacitive sender plate.  I need to cover it in sealant per the directions to keep it from vibrating loose.

I started out by fixing the anti-rotation bracket.  I smoothed on a small amount of sealant around the rivet holes, and then clecoed it in place, and squeezed the rivets for it.  I had to use my rivet gauge to find the rivets I needed, since this is sort of a “custom” part.  I also cleaned them in MEK to remove any manufacturing oils on them. After that was done, I grabbed the access plate and covered it in sealant, clecoed on the anti-hangup bracket and riveted it in place with the squeezer as well.  Then I smeared some sealant onto the shop and tails of the rivets, and put it on the shelf to cure.

Next up was to slather on the sealant into the terminal connector for the capacitive sender plate.  I covered both sides of the bolt and nut, and completely covered the terminal connection and squished sealant down inside the terminal boot and smeared it up the wire a bit to act as a strain relief.  I had already torqued this connection down in an earlier build session.

Next up was to torque down the fittings for the tank vent and fuel return lines.  I slathered one side of the washers in sealant, placed it on the rib, and then slide the fitting into place, clocking it to the position I wanted on the outside of the tank. Then torqued it down.  I did this for both fittings, and got a decent amount of squish-out of sealant for a nice filet.

Now I’m in the hose stretch with the sealing! I gooped up the inside poriton of the fittings with a nice coating of sealant (after cleaning and masking the threads of course), making sure to get a nice filet around all the mating surfaces, and covering all bits nicely.  I also completely covered the back side of the BNC connector and went up the wire a decent bit to act as a strain relief.  I also dolloped on a little bit of sealant on the heads of the rivets holding the anti-rotation bracket in place. After getting the inside done, I made nice filets on the outside of the fittings to completely (hopefully) seal them.  I set this rib on the shelf to cure.

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I still had a little more work to do.  I needed to rivet the anti-hangup bracket that goes from the stiffener up to the inside rib and install the little trap door.  Easy enough to do, and required no sealant.  I did use a rivet gun to buck these two little rivets holding the anti-hangup bracket.  I decided to re-drill the hole on the rib, as its a little to close to the hole for the screw that holds the capacitive sender on the other side of the rib.  You can see the unused hole directly below the now riveted bracket.

Lastly, I decided to go ahead and install the capacitive sender plate on the outboard side, yes the one I just slathered sealant on.  This was probably a bad idea, as I did get a little messy from the wet sealant. HA.  But its installed and ready to connect to the inboard sender when that time comes, probably next build session.

And that’s a good stopping place for tonight.  I am ready to seal and rivet the inboard outer rib once it cures from this work tonight.  From there its a water test for leaks and then final sealing of the baffle! Its getting very close to being done with these tanks! W00hoo!

Google Photos Link:  https://photos.app.goo.gl/ZAUyeq39Zvo9LymR9

Hours Worked: 3.0

The goal for tonight was to get the outboard rib sealed and riveted.  I started out with a bit of miscellaneous work first though. I did capture another time lapse, and heres that video:

I fixed up the fuel return line, and cut it to the right length, and then measured, marked and drilled the hole in the inboard rib for the return line fitting.  A step bit made quick work of this!

Then I put those inboard parts back on the shelf and grabbed the inboard rib, and T-410 stiffener so I could get them scuffed up with some scotchbrite, along with the inboard edge of the skin.  Then I cleaned everything with some MEK, and started mixing up the sealant.  I went with 50 grams, which seemed to be about the right amount in the end.

After giving it a good mixing, I used an old butter knife to slather on a thin layer where the T-410 stiffener attaches to the nose of the rib.  A butter knife works really well for this, since its designed to….spread things.  Once I had a coating done, I used some AN570AD4-5 rivets that had been cleaned in some MEK.  the 4-5 size worked out about right, after checking them with my rivet length gauge to be sure.  I used my pneumatic squeezer to set them.

Now its time to slather up the flanges of the rib with sealant, and gently cleco it in place for riveting.  I clecoed every other hole, since I planned on setting these rivets immediately, and not leaving them overnight.  Since these are the outboard rib, I was able to use my squeezer to make very nice rivets with almost zero mess.  I riveted all the holes with the squeezer.

Next up all that was left to do was to make my filets around the flanges and dollop on sealant onto the rivets.  I still had plenty left in my cup of 50 grams I mixed up, and I used the filet spoon to create nice smooth filets on the inside and outside flanges.  I thankfully had enough sealant to dollop on the rivet shop heads and cover them nicely with the filet spoon.

I also made sure to get a nice thick covering around the nose area of the rib to prevent any leaks in this critical area, making sure to get a nice filet around the T-410 stiffener as well.  I then dolloped a covering of sealant on both sides of the AN470AD4-5 rivets that were used to attach the stiffener plate.  All that was left was to clean up the excess sealant with an MEK soaked paper towel, and then clean up my tools for the night.  In my next session I plan on some miscellaneous work on the capacitive senders and the inboard rib fittings since its a little more complex with the flop tube.

Google Photos Link: https://photos.app.goo.gl/kHz1dsxVXkXePVWT9

Hours Worked: 1.75

Got a lot done tonight! I finished up the larger riveting job on these inner ribs.  I had three left from the last session, so I finished those last three up tonight. Heres the timelapse:

My tools were already ready to go from the last session, so I jumped right in by removing every other cleco from the ribs, and cleaning any dried sealant with a drill bit and deburring tool.  Then I mixed up 10 grams of sealant to use on the dimples for the rivets, and swirled a tiny bit of sealant in each dimple.

Then I stuck the rivets in the holes (these were soaking in MEK to clean them first of course).  The sealant holds the rivets in the holes really well which is a plus.

I did the bottom side first, in all three ribs, then bucked them, checking the shop heads to make sure they were set correctly.  Once I had the bottom done, I flipped the tank over and did the same for the top side.  Then I went back and removed the last clecos, and followed this same procedure to finish up all the holes.

After getting each set of rivets bucked, I’d go back and wipe what little sealant squished out with a paper towel and MEK to keep the mess down.  Once they were all set, I mixed up another 40 grams of sealant to use to make the dollops on the shop heads.  I grabbed my filet spoon and used it to make nice dollops on the tails of the rivets. This was enough to cover the ribs I left on the last session.  The left over sealant I had from getting all the dollops done, I used to touch up the filets and gooped up a nice batch in the nose of each rib to reinforce this section.  I had plenty left over so I had plenty to work with.  I eventually had everything nice and covered and touched up, and tossed about 5 grams or so of sealant.

I’m glad to get this milestone knocked out.  Its looking pretty good, and I am ready to finish these tanks.

After that, I cleaned up my tools, and work area and called it a night. I’ll let this cure overnight, then it’ll be time to start sealing the end ribs and accessories.  Those are decently fun work sessions.

Google Photos Link: https://photos.app.goo.gl/Pjcg6f1CTq4hzCpt9

Hours Worked: 2.5

This is a simple update.  I got two of the inner ribs riveted in place in this short session.  I am coming up on the end of a 48 hour fast, and was a bit tuckered out, but wanted to get a little work done, so I decided to get two ribs riveted.  Heres the timelapse of this short build.

I guessed that 10 grams of sealant should be enough to cover wet setting the rivets, and also dolloping on the tails of the rivets, but I was short a few grams and only got one rib dolloped.  No biggie, I’ll dollop the rivet tails later on.

Then I removed every other cleco from the two ribs I wanted to finish, and cleaned up any sealant that had squished into the area and dried.  I also used a hole deburring tool to clean out the countersinks and a drill bit to help with any stuck sealant.

Then, I used a toothpick to swirl a little bit of sealant into the countersink, and inserted a rivet.  Then bucked the rivets with the flush set, cleaning the little bit of fresh sealant from the flush set and bucking bar every now and then.  This went pretty straight forward and I was able to knock these two ribs out pretty quickly.

The photos above are after I had cleaned the areas with some MEK, because a little bit of sealant did squish out from the riveting process.  These things are nice and flush!  Next up I used what sealant I had left in my mixing cup to make dollops on the tails of the rivets.  I used the toothpick to sort of swirl on the sealant and it made decent little dollops on the tails.  However, I only had enough to do one complete rib, so I’ll have to mix extra next time and cover the tails of the other rib.

You can see in the photo above where I ran just short of enough sealant for dollops right at the leading edge.  Oh well,  I’ll get these guys in the next session, and I plan to mix enough to also goop the leading edge nose up really well too.  I cleaned up my tools, but left them sitting out for the next session maybe later tonight or tomorrow, depending on how I feel after I end this 48 hour fast!

Google Photos Link: https://photos.app.goo.gl/1Y4bqrYCFNeedmhP9

Hours Worked: 1.5

After a short break from the previous build session today, I came back down to get the inner ribs sealed and cleco’ed in the left tank.  This will set me pretty good to do some riveting on them tomorrow and Monday.  I would love to have this left tank ready for an initial leak test by this coming weekend!  I did capture a timelapse of this build, which is nice, because I couldn’t get many photos due to the sticky mess that is Proseal.  Heres the video:

I started out by mixing up 100 grams of sealant, and putting it into the semco sealant gun.  I love how this thing dispenses sealant.  Then I grabbed my inner ribs and squirted a bead of sealant from the semco on the flanges, and smoothed it out with a butter knife.  I am using the same procedure that I did on the right tank in this build log: https://theskunkwerx.com/rv7/sealing-the-right-tank-ribs/

I first slathered on sealant on the bottom flange, curling it around the leading edge and back a few inches onto the top flange.  I am cleco’ing the bottom in first and then once I have all the ribs clecoed to the bottom, I buttered up the top flanges .  Once the top flanges are buttered with sealant, I took the skin, and gently slid it down into the cradle cleco’ing the ribs in place.  This worked really nicely to getting the ribs clecoed without smearing the sealant off the flanges.  Check the video for a better picture of how I did this.

After I had all the ribs clecoed 100%, I used the semco to squirt a nice bead on the edge of the flanges that I used to make the filets with a filet spoon.  Around the second rib, I ran out, so I had to mix up another 50 grams of sealant which was just about right, leaving me with about 10 grams extra that I squirted into the leading edge of the ribs for extra reinforcement.  Here’s how the filets came out:

Then I clecoed on (without sealant for now) the end ribs just to help the skin hold its shape while the inner ribs sealed.  I also strapped some masking tape across the skin at the ribs to help squeeze the skin together to assure a good bond of sealant at the aft edge of the ribs.  After that, it was cleanup time! I’ll let these sit overnight, and then rivet them tomorrow and Monday.

Google Photos Link: https://photos.app.goo.gl/jUSa1nX14A2bcixf7

Hours Worked: 2.0