Not much to add to last weeks post to be honest. This week started out by riveting more of the baggage area…
And in between riveting the fuselage I started riveting the flap together.
It’s funny how quickly it all comes back when you work on something from way back in the project.
But eventually, all the flap riveting was finished and it is ready to be mounted back on the wing.
So, back to the fuselage the firewall sealant had arrived which meant that I could finally close up the front of the fuselage. I pealed back the side skins and applied the sealant.
I applied sealant to the bottom of the firewall (top in this picture) and then riveted every rivet I could reach in the forward side skins. Lastly, I fitted the floor skin and cleco clamped every hole.
That’s it for this week. I know it doesn’t seem like much but given the circumstances I think it’s making great progress.
So the paint was dry (enough) and I could start reassembling the fuselage for the last time.
It’s been a long time since I last riveted anything so I started with something easy, the bracket for the autopilot servo.
Then the stiffener for the aft F-706 bulkhead.
Once that was done I put jointing compound on and cleco’d the F-706 bulkhead into the aft fuselage.
Next I riveted the gussets onto the firewall as per the instructions.
And riveted on the angle brackets to the forward longerons. I won’t rivet these onto the firewall until the fuselage is together.
I then pre-riveted on the Gear Attach webs to the F-902 bulkheads. Doing it now is much easier than when everything is back together.
Next I riveted on the nutplates to various bulkheads.
Then the F-704 doubler plates.
Next I fitted and torqued nuts and bolts to the F-704 bulkheads as per the plans. Again much easier to do now than when it’s all together.
Then I fitted and riveted the outer seat ribs.
and torqued the bolts. (If you’r building don’t do this now, it interferes with 2 rivets you need to set).
As I’m building a tailwheel I filled the unused holes for the main wheels with AN4 bolts as per drawings.
Then I got stumped.
The plans have you run the wiring down the centre channel all the way up to the F-706 bulkhead. There are holes for the wiring in everything except the F-706. I can’t see how or where to drill 2 wiring holes without weakening the structure or interfering with the elevator push rod.
So I called Richard for a quick brain storm. In the end we agreed the best way was for the wiring to transition from the centre of the aircraft to the next ribs under the baggage floor. But, the baggage floors are supposed to be riveted into place permanently.
As there were nuts and, now, wiring in that bay, I didn’t like riveting up the floor permanently. So I called Nigel (my inspector) and asked permission to make the baggage floors removable.
He said that was find so the next job was to fit nutplates to all the rivet holes.
That took about 4 hours to do everything and in some places it needed the one legged nutplates.
Eventually they were all done and I was pretty happy with the results. Only time will tell if anything else interferes with any other parts.
Once I was happy with the centre section and there was nothing more I could possibly think of doing it was time to flip it and attach it to the aft fuselage again. Thanks Jake for your help.
I then started locating all the parts and reattaching them.
While on a tea break I spotted that I’d missed priming an overlapping part of the structure. Doh! So I quickly knocked up both primers and got it done.
Next I started riveting any hard to reach rivets that could be done now such as the three aft arm rest rivets.
Next I riveted the aft support rib as far forward as I could – some overlap with the side skin so I left those.
Finally, it was time to fit the main side skins. But first every contact surface needed JC-5a jointing compound.
Then on went the skins.
Once the skins were on I started fitting all the parts to the forward fuselage.
I peeled back the front of the skins just enough so I could rivet the angle bracket to the fuselage.
Then I looked for any more rivets I could do alone such as the ones around F-704 wing slot.
Finally, I fitted and torqued the 4 bolts that attach the firewall to lower longerons.
That’s it, everything I can do solo is now done. What’s needed next is a riveting buddy. Any offers?!
After quickly finishing the last little bit of work on the armrest reinforcements it was time to wash and degrease the last of the parts. Some of these parts were so big they had to go outside to be degreased.
As before, I knew when the parts were grease free when the water sheet off the parts. The dog thought it was party time.
Eventually all the parts were washed and degreased and it was time to spray it all with etch (wash) primer.
Once the etch had dried I then sprayed the cabin parts with acrylic 2k paint in my chosen colour – RAL7001.
Anything that was not going to be visible in the cabin I sprayed with PR143 primer.
I also primed any parts of the outer fuselage that overlapped other parts.
I did the same on the massive longerons. The aft section was primed with PR143 and the forward part was painted with RAL7001.
I also realised that there were a bunch of parts I had primed previously – like the firewall and F-706 bulkhead that needed to be painted so I gave those a shot of RAL7001.
and the uprights for the mid section.
Finally I took the big F-770 skins outside and sprayed them with RAL7001 too. The first one sat there and dried within an hour or so. I swapped it out with the second one and gave that a coat of grey.
As soon as I’d finished spraying the second skin I was done painting. Yay! So I started tidying up the workshop.
After about 10 minutes into the tidy up I heard an almighty clang coming from what I thought was a neighbours house. Until it dawned on me…
NO it can’t be!!!! Please no!…
Yes, it was my skin! A gust of wind had caught it and slammed it to the ground!
After a moment of staring in disbelief, I grabbed the skin as carefully as I could and put it back on the table. While I waited for a break in the breeze so I could safely run into the workshop and grab a piece of wire to tie the skin to the table to stop it happening again I examined the damage.
There was nothing I can do while it was wet so I left it to dry.
After about 4 hours I came back to the skin and decided to sand off the affected areas. The paint was only 4 hours old so it should come off pretty easily.
I started with some maroon scotchbrite pads. Useless! Didn’t even mark the paint.
So I used some 400 grit emery paper. A very light mark but it wasn’t making any headway!
So the good news is this paint is tough! Perfect for high wear area like the cockpit.
In the end I used 200 grit sandpaper and smoothed as much of the damage as possible and worked back to the emery and then the scotchbrite.
I then took the skin outside, set it up on the table (tied of course) and then sprayed over the sanded areas.
What a week but I’m glad the painting is all done!
As I’ve been disassembling I’ve had this nagging voice in my head telling me I’d missed something. Sure enough I had missed a couple of 1/8″ holes that connect the F-902 bulkhead to the longeron. Not a massive problem and easily done after the fuselage is rebuilt but luckily I was able to do this now while those parts were still together.
Once that was drilled I then went on to dismantle and prep the F-604 bulkhead.
So at this point in the plans it says ‘before you continue there is a laundry list of items to complete’.
The trouble is, that’s pretty much the end of the laundry list. So, what is there to do? How do I know what I need to do?
To find out I studied the plans in intense detail looking for anything I may have missed. I enlarged some of the smaller holes as per the drawings.
Then I had to decide where to put holes for the things that aren’t on the plans. Such as the AoA tubing and autopilot wiring.
Once again, it was very difficult to know where best to put the holes without fitting the wing and wiring. So, a trip up to the local farm strip to see Richard and his flying RV-7 was in order. It’s hard to see from this picture but it really does help seeing how he ran his plumbing and wiring.
When I returned I was greeted with a small envelope in the mail. Yep, it was a new valve for the compressor. Hooza, compressor is now working again!
So I spent the rest of the week looking for bits I’d missed, marking up what to dimple and, more importantly, what not to dimple.
I did spot one item I’d missed on the rear fuselage, a small joint plate. Tricky to do while the fuselage was assembled but nothing a paper template and some imagination couldn’t solve.
There is the drawing on paper.
Transposed to metal.
Cut out, match drilled and dimpled. I’m pretty pleased with those.
Next was to finish off prepping as much of the baggage area as possible too.
That’s it for this weeks instalment. I still have a nagging doubt that I’ve missed something so I’m off to read some other builders logs for inspiration.
I started this session by clamping and drilling the black rudder blocks to the forward longerons and the rudder brace.
Not having the seats in the aircraft yet, it was very difficult to judge where to fit the pedal assembly so I drilled plenty of holes to allow for maximum adjustment instead. All as per plans.
Then I removed the centre rudder bracket and deburred, edged and scuffed it ready for priming or painting.
The next job was to drill the inboard floor stiffeners to the bottoms skin. I just clamped them in place and then drilled them from the top.
I then drilled the stiffeners to the brackets on the inside.
While drilling I heard an unusual hissing sound in the workshop. After a short while I tracked it down to the compressor. So I removed the side panel of the enclosure I’d built to investigate.
With the side panel off I could tell the hissing was coming from the valve on the blue compressor tank. So, naturally I lightly touched the valve to see where it was leaking and
The valve vanished with an explosion that I can only liken to a gunshot. Not seeing where the valve went I instinctively checked myself to make sure I was OK. Shaken but, thankfully, OK. My heart was pounding so hard I decided that was enough for today. So I switched off the lights and went indoors.
Close up of the valve MIA…
The next day, and with my heart back at normal pace, I located the broken and missing part.
A quick search on the Internet soon has a couple spares on their way to me. So temporarily it was time to use the battery drill.
Next on the schedule was to drill the outer floor stiffeners to the bottom skin. The problem here is that I needed a hand so I called on my good friend Richard who managed the drill while I held the floor stiffeners in place. Good communication was definitely required here to avoid fingers being drilled. But, quick as a flash, they were done.
Next I located the baggage side panels and cleco’d those in place and then match drilled the various sized holes to the main structure.
A bit more match drilling on the outside too and that was it for this weeks sessions.
The fuselage is almost ready to dismantle for deburring, edging and scuffing but before I do that I want to make sure there are no other tasks left to do.