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.

Glamor Shot!

I was out at the hangar tonight, working on Brake master cylinders and the Cleveland calipers. I put the fuselage out of the hangar in the grass so I could have more room to work. Well the Sun set was nice and I thought I would take a Glamour picture.

As she sits here, she has all new control cables installed with all new Pulleys. Also rebuild control column and Dual brake / rudder pedals.

Working on Floorboards and Brake lines now, next will be 1/2″ fuel lines and selector.

Pitted races

Well, this weekend I wanted to get the tailwheel built up and mounted on the airframe so I can roll the darn thing around. Well as I gathered all the pieces together and started a final inspection, I noticed the Scott 3200 wheel bearings were pitted.

Next comes the research to replace them. The Bearings are Timken A4050’s with a race A4138. Looking at the regular places like Univair, Aircraft Spruce and others, these bearings are very costly considering their size. To get the Bearings, races and dust covers is over $270.

If you look up the timken A4050 on its own, you can find the bearing for MUCH less, like $40 for two bearing and race sets!

So now you are asking why? Why are the SAME bearings 1o times more expensive from the Aviation parts houses? Well I found an interesting post on this McFarlane site stating that the Aviation grade of the A4050 actually has a part number A4050-20629.
https://www.mcfarlaneaviation.com/products/product/A4050/

You can see that the A4050-20629 has the FAA/PMA stamp and appears to be a black roller cage.

Tailwheel, WRONG

So I started re-building the Scott 3200 Tailwheel, refinishing the spring and such. I have the pictures of when I took the tailwheel apart and I was going to reinstall the same way until I read something in the 3200 manual that made me question something.

My original setup had 4 grade 5 bolts holding the leaf spring to the fuselage, but the 3200 manual mentioned two U-bolts. I went to the Univair site and verified the same.

So when you re-install your tailwheel ensure you have the U-bolts.