The Rebirth of Cessna 140 NC3771V

[regular122]

Update 13 March 2021 - Many weeks of cold temps, foul weather and the need to fly on the few days of good weather have prevented my work on the plane. I have however made a few inches of progress. Not exciting stuff but stuff that has to be done.

The comment by 2356 about an inner ring for the landing light is correct. I fabricated one out of .020 Alclad with a Dremel tool cutting wheel to hold the landing light. It actually takes 11 nut plates on a circular mount. I also found some AN505-632-R10 single slot, flat head, aviation screws to mount the light, although in the pic it shows a few screws I stuck on to see if it would mount correctly. It did.

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Continued below....

[regular122]

Update 13 March 2021 - Decided to work fairings yesterday and today. They looked pretty ratty. It was tedious work because of the primer and paint on them. I finally got it all off after much scraping, a heat gun and then scotch brited the paintless parts. I can't decide yet whether to paint them the wing color (silver) or leave them bare aluminum.

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I also got the GE AS1B Transceiver in thanks to Dave Pyatt. On a whim I asked on the FaceBook Group page what the odds were I could ever find one and he posted he thought he had one in his hangar. He did! Very thankful to him for parting with it. I will likely use the face as a door for the Narcos that are in it as this thing weighs a ton and can't be used for transmitting today. Still, it is pretty cool.

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Next I need to lay some wire for the landing light before I close up the wing. As the weather improves, I plan to get both wings done before it gets too hot in the summer. Little by little.

Steve

[8424]

Thanks for the update, Steve!

I check every day to see if you have made more progress. The cold really shut us down working on our planes here in Oklahoma!

I finally got all my tail parts prepped for paint, now waiting on my IA (who also restores an builds hot rods) to do the painting.

I like the bare (polished) aluminum on the fairings. They look like they are in good condition.

I really like the old radio cover idea!

Steve A H

[regular122]

Been a while since my last update. Work has been slow due to work on a Cessna 150 donated to our non-profit, the Redeemed Flying Corps.

30 Apr 2021 Update - Temperatures were finally sufficient to have three consecutive days of 65 degrees F which is important for the bond used for the coping of the wing leading edge. I applied the Stewart's System EkoBond to the felt and then let it set for when the wing is covered. Other than looking like a 1970s sofa, it set well and will shrink when heated forming a strong bond of the fabric along the leading edge while the felt covers the rivets and aluminum sheet joints.

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Next I decided to figure out a way to mount the back bracket for the landing light. One of the mysteries to me what why a back bracket rather than a direct screw mount on the exterior side of the wing. But upon examination, it makes sense that the friction of the mounted light flange could rub through the fabric at the screw mounts, weakening the fabric of the wing. So Cessna made a lamp band or bracket to go behind the flush outside part of the wing to make it more smooth. In every diagram, I did not see how they mounted the bracket. Sure, the screws hold it in when the lamp is mounted but what if the lamp is removed? It could come loose and have to be fished around and lined back up inside the wing. So, to remedy that, I just used rib tape to mount the back bracket. It is firmly in place for the screws to be slid through the other side and should remain in place after the wing is covered and the lamp is removed for maintenance, etc.

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Once I can get the old wires replaced for the Landing Light, which I ask for assistance on here (viewtopic.php?f=7&t=1503) I will cover the wing.

Steve

[regular122]

New Update.

28 May 2021- I appreciated all the help from association members on the wiring advice. I was able to source some MilSpec #18 and #8 wire for the Grimes Light. I used Hammer Head connectors to keep consistent with the other wiring. I marked the leads and halfway down the wires with tape and gave them the same numbering (A39, A40, A43) as the Cessna 140 Manual diagram of the harness so future owners can see what wire is what.

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More to follow in next post...

[regular122]

....Continued from previous post

31 May 21 - With the wing wiring done, I was excited to finally work with the fabric. I am using the Stewart's System. I really like it. No smell, no danger with skin contact, no trying to race against the bond drying, no toxic MEK to damage your liver and mess up anything it touches.

The first step was to make the fabric coverings for the flap & aileron gaps and the wing root ends. I was happy to be under the watchfull eye of Gary Manning, the A&P who checks my work.

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I am using SuperFlite 102, a medium weight fabric. After spreading Ekobond on the contact surfaces for the end caps, it takes about 10-15 minutes to get to a tacky composition. Since it was a little colder, it took longer. Crazy weather to be in the 60s in June. Not that I am complaining. Once the glue is tacky, you can press the fabric pieces into it to provide a temporary hold and then hit it with the iron at 250 degrees to provide a more solid hold. You can still adjust that by pulling and straightening if needed. Here Michael Willman helps me with the stretching and tacking.

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Now, with the end caps done, I can lay out the blanket of fabric on the bottom of the wing.

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More to follow in next post...

[regular122]

....Continued from previous post

1-3 June 21 - I was able to take a few days off and decided to hit the left wing with some activity. With the end caps set and lightly shrunk, now I was able to lay out a blanket of SF 102 fabric and form the bottom covering. The first step was to lay a layer of EkoBond along the leading edge felt. I placed the bond to allow the edge of the fabric to be above the leading edge, which will set it for the other side of fabric to overlap 3" and get the seams off the center of the leading edge for airflow. EkoBond is so easy to work with. Once I place it on the felt-coped leading edge, it tacked up and I could temporarily stick the edge of the fabric to it and align the warp and weave to be square to the wing frame.

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Once the leading edge was tacked and the lay of the fabric was correct, I then applied bond to the back aileron and flap surfaces only, being careful not to place bond underneath or on top so I could get the best shrink of fabric when heated. The good news about the Cessna 140 wings is that they have ALOT of surface area back there. I tacked the entire back surfaces and then applied a bonding coat on top (the blue areas).

Next came the wing tip. Ensuring I had a 1 inch overlap underneath for fabric on metal, I applied bond and let it get tacky, then pulled, formed and hit it with the iron at 250 degrees to give it an initial shrink. It turned out well with no wrinkles.

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Although I wrestled with it, I decided to cut the fabric at the wing support joint. It just sat too high for me to lay the fabric properly along the leading edge. Once I did, the leading and trailing edges fit nicely. I was concerned that by cutting it before the initial stretch might move the holes and create the need for a bigger cut or hole. That was fortunately not the result in this case.

After the leading and trailing edges were set in proper alignment, I applied top bond to anchor the fabric before giving it the initial shrink. I did the same on the wing tip and wing root areas. Now the bond should anchor the fabric to all the edges of the wing.

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More to follow in next post...

[regular122]

....Continued from previous post

With the bond setting overnight, I then was ready to do the initial shrink. I used a German rectangular ski wax iron this time rather than the small curved iron. It is also digital adjustable but in Celsius. So, I converted the 250 F and arrived at 121 C for the iron. The nice thing about this iron is its big squared size. At this temperature on SF 102, you can literally lay the iron there and it will not over shrink (still I would not recommend that).

I started about 5 bays in, centered on the bay and then ironed up and down in that bay in each direction. From there I moved to bay 2, then center bay, 1, then alternated back and forth until all bays were done, ensuring the warp did not pull in any direction but parallel to the wing. It laid out very nice and taught, with the little wrinkles sucked away as the iron moved over the fabric. I also ironed out the leading coped edge, which flattened the felt.

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Once the fabric was stretched, I then made the reinforcements for the support joints and fuel sump. I simply cut cloth to fit the metal underneath in the same pattern and cut it with pinking shears for a nice bonding edge. I still need to make a reinforcement for the landing light area.

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Now I am ready for the top fabric, which I hope to get to tomorrow.

Although there is still a lot of work to be done, overall at this point, I like the result.

Steve

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[regular122]

Well, it's been an awful long time since I posted anything. I thought I should catch up a little and detail the work done. Like most human beings, work and travels made progress go much slower than desired. I think I've moved the project from the 12th of never to the 11th now. But month by month, the restoration takes shape.

June 2021 - After the bottom fabric was in place, I then made final preparations for anything inside to be done. I will not be able to access the wing this freely again. While access covers will be installed, they will not give the full view. So with that, I made sure the landing light wiring was set and added a 'Superflite' label inside the Landing Light mount so whoever eventually opens up the wing knows what I used and did. Very few areas I used have the inked label, so I wanted to make sure something was in there.

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I also had to ensure the gas tank foam donut support was reinforced. The 73-year-old one was still in decent shape but had shrunk over time. I added foam under it and along the seam to give it new life.

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After a thorough inspection of everything inside the wing, I laid out the top fabric and tacked it to the bond on the leading and trail edges.

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Continued in next post....

[regular122]

July 2021 - The next step was to tack down and pre-shrink the top fabric. Seth Johnson helped me with the small shaped iron to smooth out any spots while I hit the panels. 225 degree pre-shrink after all edges were secured with Eko-Bond.

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I used the same procedure as the bottom fabric with alternating panels in a sequence - Bays 5, 2, Center, 1, etc. Then I added the Gas Cap reinforcement fabric. The overall look came out nice.

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After the shrink, then cloth cotton tapes were added on each rib to support the Cessna metal 'staples' or more correctly, the fabric clips. I used a metal compass set at the proper width and then punched holes through the fabric in the ribs. This made for much faster work and I could hit the exact spacing by just setting one part of the compass in the previous hole. It also helped to set the cloth tape over the top of each rib rather than punch through both layers and ball it up.

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