The front and rear collars for the tube were binding pretty bad. Closer inspection told me that the collar inside dia' was smaller than the tube that was trying to sit into it. For a while, I scratched my head wondering how this thing flew OK for many years, since there was so much binding and misalignment in general. I am beginning to think the torque tube came off of another airplane...
I needed a 1.5" reamer. Luckily, I had an adjustable reamer that size to hand from when I was working on the tailwind gear/engine mount. Problem was, I had welded a t handle to the reamer and I couldn't use that due to clearance issues on the fuselage. I cut the t-bar off, took the reamer to a buddy with a bigger lathe than mine, and he turned the end so it would fit in a 1/2" chuck on my hand drill....
Hopefully, I had enough low torque low speed on the hand drill for the reaming to work. It wasn't great, but it did the job. I bolted both collars together sans tube and after an hour I was covered in sprayed cutting oil, but they were reamed. To finish the job, I honed the collars, again, I had a 1.5" hone from the landing gear project that was at hand. Now I had to fit the torque tube and hope that my free hand reaming had not made things worse....fully bolted, I had a 'little' resistance, I backed off and added some .010 shim stock - perfect. Phew. If all this had not worked out, I was going to cut the darn collars off the fuselage and take the phenolic material approach that forum member Scottly took.
Having had a new boss welded to the tank, I had to pressure test it again. The leak test kit from Vans aircraft is cheap ($5-10), pretty simple but effective. Fit a supplied valve to any inlet, put a balloon over another, add air. You only need a couple of pounds, but if you go over, no worries, since the balloon deals with the excess. Then check the joins with leak detector or bubbly washing liquid. The balloon in the pic stayed as-is for a whole weekend.
I needed to mount a halon bottle somewhere, I finally came up with a location, see inset pic.
The seat backs are made from 1/4" lauan faced ply with a poplar core, courtesy of home built depot. I added some lightening holes to non-pressure areas. I thought about making some sort of hinged set up for the seat back, then decided that access would not be needed that much, so I kept it simple by adding a basswood frame. The seat back simply presses into place. The front seat will be bolted into place, it will also have a radio stack deal attached to it at some point, so tabs were welded in. A bolt will pass through the seat back/3/4" basswood frame/steel tab/stack.
I keep looking around the fuselage for things to weld...I just have a couple of brackets left to weld on for the canopy mechanism, then it looks like I am ready for sheet metal.