Attachment 26646
I cleaned up the shop (mostly) and set out my sawhorses two days ago. My digital tape measure and digital level came in handy for setting up the wing fixture. I fixed one to the garage floor with Bondo and once it kicked off I got the second one leveled, oriented by the book and also fixed to the floor with Bondo. Yesterday morning I checked all the measurements again and they were spot on. Both sawhorses were level, my 156" dimension was not even out 1/32" and the diagonal was within 1/32" out. For some repurposed studs I'm pretty happy with it.
Attachment 26649
With that all checked I cut some lumber for the index blocks which attach to the saw horses and the 1/2" pieces which serve to stagger the spars at the inboard rear end and to set the washout. By afternoon I was removing screws from the spar crate. I tested out my fixture and then got busy with a scotchbrite pad cleaning up the outside of the tubes. It was one of those nights where you are about ready to shut off the lights and decide to see what kind of effort it will take to prep the spar inserts, and next thing you know it's 1am and they're done.
Attachment 26648
During an afternoon break I went to the local building supply place and bought 14' of 3" PVC pipe (had to buy a 10' and 4' piece), a coupler and two end caps. Armed with knowledge of the "tennis ball trick" I included a big pet store in my errands. I thought it would be great to find some smooth rubber balls instead of tennis balls, and fully expected to strike the mother load. I was to be disappointed however, and the best I could do was some overpriced tennis balls.
Around dinner time I slapped more Bondo on the feet of both sawhorses and used some PVC pipe adhesive to bond the coupler and one end cap in place. Then I vacated the shop while all the fumes cleared out.
Attachment 26647
Today I explored the tennis ball thing. I wanted to slosh the inside of the tubes with acetone. The balls leaked pretty badly and acetone will just laugh at any attempts to tape it. I just lived with the leaks and had a big tub at each end to catch the leaking acetone, which I filtered and used for the initial sluice of the next tube and fresh acetone for the second. I retrospect I should have started by cleaning up the insides of the tubes because I had cleaned them externally to a beautiful uniform appearance.
Once all four spars were cleaned inside I mixed up a big batch of my Henkel Bonderite etch solution. One at a time I etched the spars, and two at a time I etched the inserts in my big PVC tube, sloshing continuously for 4 minute cycles.
The inserts were the last thing etched and the first things I ran through the Alodine process. They came out looking pretty nice. The spars came out splotchier than most parts that I have Alodined. Until this job I have been able to run them directly from etch to rinse to Alodine without drying the parts. The instructions say that if you don't dry them they might not be uniform. Working alone and needing to get all the way through etching all the parts before I could Alodine them made the job challenging. And lest anyone think they're splotchy or terrible they look fine, just not perfect. They didn't pick up quite as much color as usual but again, no real impact on the treatment process.
The lack of uniformity has no impact, and I'm used to seeing parts like this. They were treated with etch and Alodine so the job is done. I was pretty worn out by the time I cleaned up. Actual hands on time (not including the tennis ball acetone task) was about 2.5 hours. Damn glad I'm not building a biplane.
Tomorrow I'll start the process of sliding the inserts into the spars.
Re: Project 5 build thread
Originally Posted by alexM
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