Soda and patterns

Today, the weather in Dallas was PERFECT, so I got out the Harbor Freight soda blaster and worked on the light surface corrosion inside the vertical stabilizer. Only took about 45 minutes and a lot of dust, but the inside looked great after. Later I took it down to the airport and sprayed the inside with Zinc Chromate Primer (after flushing with water and drying of course).

I also “Dry fit” the OLD cargo floor and front wall to evaluate using aluminum to replace each and the use of Oratex as a side wall covering. I came to the conclusion that I may want to go with the original cargo canvas material, because if I cover the entire cargo area with Oratex, then getting into the aft fuselage may be difficult. I may use a local upholstery company to remake the cargo envelope.

I watched a video on YouTube about using this material used to protect new floors as a great thickness of cardboard to make patterns. Well I gout out my floorboards and made patterns. I plan this week to go to a local meta sales store and see if I can buy aluminum plate that is waste from drop cuts.

Considering everything from diamond plate, to smooth aluminum with anti skid material. Also considering either powder coating or cadmium plating. Stay tuned.

Oratex decision made

Tonight I also made a decision on Oratex. I decided to use the dark navy “Corsair” blue for the exterior and Bright Silver for the interior.

Yes, I plan to use Oratex for all the interior covering, it will be very light and provide more space is it is expressly thin, yet strong. Also easy to install inspection plate and such.

I tried to estimate some rough material needs with some measuring tonight. The material comes in two widths, 42” and 71”. Then you purchase in 1 meter linear lengths.

The 42” wide runs about $68 per liner meter.

Cleveland’s

Slowing working on the Cleveland brakes. Sent off the brake lines to get rebuilt and while they are gone I’m working on the calipers.

I had bead blasted the outsides and cleaned them well, but because the aircraft had sat since 1983, there was residue of the O-ring on the bore of the caliper.

I used some X-50 anti-corrosion spray and a scotchbrite to clean that area up. In the picture below you can just see that ring in the bore of the caliper on the Left and how clean the one of the right is.

Aslo found out Univair sent me the wrong -O-ring for the Piston.

Latest surprise

So if you ever take on a project like this, be aware that there will be surprises. Today is no exception. So I thought after Brent Henneman finished my welds, and the IA signed off that the fuselage was ready for final paint, I was ready to make a milestone in the restoration and begin “Building” instead of”Teardown”, well here is the story.

I reached out to Legend Aircraft Company in Sulfer Springs Tx because they have a paint booth and know how to paint tube fuselages. Darin, the Owner of Legend, told me to bring the fuselage out and they would take care of it, so Brent and I loaded it up on the truck and headed out there.

Loading up the Fuselage at Brents

So we drove out to Legend Aircraft and unloaded the fuselage and started to carry it into the Paint shop. While doing that Darin started looking it over and his keen eye noticed some issue. First in the upper part of the cockpit he noticed one diagonal tube was bent. I have to admit that I focused on the lower sections of the fuselage because of checking for corrosion and such that I never really looked at the top. Then as Darin began looking closer and then it happened!

Darin noticed that the forward wing attach compression tube was bent downward. This make sense because the aircraft had history of groundloops and that tube would be compressed in those cases.

Approx 3/8” gap between the straight edge and the compression tube on my frame. Most likely the ground loop caused it.
This is Brents Stinson as a comparison, you can see no daylight between the straight edge and compression tube.

OK, now I feel I have been kicked in the gut! I went from feeling excited about getting this painted and starting to build, to “What the hell am I going to do now!”. Darin stated that to cut that out and replace would take a fuselage Jig. I think from his position of building new Cub fuselages each day, its no big deal, but there are not Stinson resources like that readily available.

Well I knew that this was not going to be fixed quickly, so we loaded it back onto the truck and drove back home.

Now I had to start reasearch on options. There were two camps.

#1 would be to find a replacement tube, cut the old one out and weld the new one in. I found that Univair does NOT produce this part any more, so I would have to get a used one or make one. I did find that Earl Allen had some in CA, and Steve Ruff had make some in WA.

#2 would be to “Bend” the tube back straight. This would require bolting the fuselage down to the ground, and using a winch to apply pressure to bend the tube back to original and maybe weld a re-enforcing bar on the tube.

While this may “Work” it is not listed as an approved repair in FAR 43.13

While considering these options, I started looking for another fuslage, just so I could evaluate the cost of replacement, bending or a new fuselage. Well surprise, surprise. I find Robin Ange on Facebook is selling some extra Stinson parts. He and his Dad were rebuilding two Stinson 108s one hour south of Frankfurt Germany. Yes, I said Germany! We started talking, and this fuslage is a straight no damage history frame that was in California before it got shipped to DE. The lower longerons have been replaced and they boroscoped other tubes.

I plan to purchase his frame, and the birdcage and have it shipped to DFW. I will fly over to Germany to inspect prior to purchase. How can this be financially feasible you ask? Well I’m a Captain for Southwest Airlines so I can get back and forth to German for essentially free, and his dad is a Captain for Lufthansa so they can ship the frame via Lufthansa Cargo for an amazing price!

New Frame in Germany
Frame will include the Birdcages as well!

Disassembly of rudder pedals

Today I took the rudder pedals apart in prep for installing them in the fuselage when it returns. 

There is a good article on this at http://www.hangar9aeroworks.com/108Torquetube.html

Planning on blasting the pedals, but not the torque tubes as they are two piece and lubricated so they move to actuate the brakes. Don’t want any blast media in there. I will be painting the tubes once cleaned. the bearings are in decent shape and I will know more after the cleanup, but I may have to take the advice from the site above and replace with a similar bearing.