The Barn Find Build

[bbs428]

Much better result on your "tips" than you had before. I went thru much of the same with my 5.

Never ceases to amaze me what poor workmanship is tolerated in a machine that literally has your life dependent on said workmanship. Luckily for me my guy stopped on page 30... Lol.

Going thru everything with a fine tooth comb will pay off handsomely Eric.

[Eric Page]

Holy cow. That photo is a horror show; it makes my builder-fabbed parts look like Boeing spec!

[Jerrytex]

Wow! "Hmm.... sure wish I had a hacksaw and a file......guess this machete will have to do....."

[Eric Page]

Had a couple days of distraction, but got back to the plane last evening. I sanded down the Hysol on the tips of the vertical and horizontal stabs. The vertical ended up looking very smooth and had a nice shape, but the Hysol was thin enough that it felt a bit softer than I would like.

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I didn't take photos, but after the sanding I applied another slathering of Hysol to hopefully give it a harder shell.

The tips of the horizontal still had significant low spots after sanding...

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...so I also put another coat of Hysol on them and will sand again once it cures. If I had any brains, I'd use SuperFil. Big if...

[jrevens]

FWIW, I made all of my tips completely out of Hysol or West System epoxy with a LOT of micro balloons. Light, easy to sand & very strong. Touched-up as necessary with SuperFil.

[Eric Page]

I was expecting to do some more Hysol sanding today, but with my garage being so cold overnight, the Hysol didn't feel quite fully cured. I took the horizontal stab inside so it would be warm overnight tonight, then moved on to other things.

I started by installing the elevator push-pull tube, pulling four new rivets in the aft reducer bushing and greasing the area that passes through the mid-fuselage bushing. I was pleased to find that my measurements for the bare area were spot on; the paint gets to within 1/2" on both ends of its travel.

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I stole an idea from alexM to use nut plates below the rudder torque tube brackets. I was going to use Click Bonds like he did but I just can't stomach their price, so I opted for F2000 and F5000 floating anchor nuts mounted with 3/32 stainless steel flush pop rivets. I started by using a dab of CA glue to fix the plates under the C-channel with the nuts centered under the 1/4" holes.

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Using the plate holes as a guide, I drilled the C-channels for rivets, then set up my countersink cage and countersunk the holes on the top side. Before installing the plates for good, I popped them off, cleaned the C-channel with a wipe of acetone and shot them again with primer, then paint.

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Finally, I installed the anchor plates with rivets.

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Since I was in a riveting frame of mind, I also installed the flap handle detent bracket in the center console. My next door neighbor's 6 y/o daughter has expressed interest in the project, so I invited him to bring her over to pull the rivets. Unfortunately, she had been outside for awhile (launching model rockets!) and was cold. It was a choice between the funny guy next door who hangs out in his garage all day, or Mom and hot chocolate. Needless to say, I had to pull my own rivets. So, working alone, I prepped with Scotch-Brite and acetone, applied Hysol, clecoed the bracket in place and pulled the rivets.

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More Hysol sanding tomorrow.

[avidflyer]

Interesting thing in your post about greasing the part of the elevator push pull tube. Some have said that should not be greased but rather left dry, as the bushing is slick enough on it's own. Another argument is that the grease can pick up dirt which causes wear. Don't remember if the manual addresses this or not. There was a post on FB, and the person's bushing had slid out. His elevator tube was greased as well. So for the other half of the discussion, it may be a good idea to make very good and sure that the bushing can't come out. I had grease on mine in the Kitfox 4, and a few weeks ago when it was about 5 above, my bushing slid out as well. I put a rag on a stick, and was able to wash off all the grease with gas on the rag and a bunch of rubbing. Sure wish I could get back in there and put a real short screw through the bushing holder into the bushing, but there is no way I'd ever fit in there. So far the bushing is staying in place, and yesterday I was flying in about +10 or so temps. JImChuk

[109JB]

Interesting thing in your post about greasing the part of the elevator push pull tube. Some have said that should not be greased but rather left dry, as the bushing is slick enough on it's own. Another argument is that the grease can pick up dirt which causes wear. Don't remember if the manual addresses this or not. There was a post on FB, and the person's bushing had slid out. His elevator tube was greased as well. So for the other half of the discussion, it may be a good idea to make very good and sure that the bushing can't come out. I had grease on mine in the Kitfox 4, and a few weeks ago when it was about 5 above, my bushing slid out as well. I put a rag on a stick, and was able to wash off all the grease with gas on the rag and a bunch of rubbing. Sure wish I could get back in there and put a real short screw through the bushing holder into the bushing, but there is no way I'd ever fit in there. So far the bushing is staying in place, and yesterday I was flying in about +10 or so temps. JImChuk

To support what Jim is talking about, the Kitfox 4 I'm working on now had grease on that bushing too and it was pretty gummed up. I washed all the grease off and now it is greaseless and will stay that way. Don't know that the bushing ever came out, but I see no reason to lube a plastic bushing.

As a matter of fact, My Sonerai has a similar arrangement, except it has a steel tube pushrod instead of aluminum, and that steel tube runs in a steel bushing welded to the fuselage much like the tube that holds the bushing on the kitfox, except there isn't any plastic in it. Its not lubed either but I did make sure to smooth the ends and bore of the bushing tube.

[alexM]

You need to get back to your day job so I can keep up. Looking great Eric.

I'm not planning on greasing my elevator push-pull tube bearing at all, and if I do it will be some sort of dry film lube.

I can't con any kids into pulling rivets either, so I bought a Milwaukee 12V rivet gun. Damn near 100 stainless rivets just getting the inserts in my spars and over a 100 more to go.

When you're sanding Hysol and it seems even a tiny bit gummy, walk way and leave it for another day. Same is true with SuperFil. When I did the top of my vertical fin I was meticulous with the balsa piece. After just one coat of Smurf poo it looked great, so I did one thin layer of Hysol over that and declared victory. With the horizontal stab and elevator I did some approximations with balsa wood and slapped on enough adhesive that I figured it would be smooth after one sanding. Not so much. I think it took three layers before all the little voids were filled in.

[Eric Page]

Interesting info, guys. The original tube that I removed had black dust smearing where it passed through the bearing, which looked to me like the result of aluminum fretting. This is why I lubed the replacement. However, I'm sure you're all correct that the grease will attract dust/dirt and eventually turn into grinding paste (given the dust in my garage, this will probably happen before covering). I'll remove the grease. I suppose that means drilling out the rivets again...

Re riveting, I've got one of those Harbor Freight air-powered rivet guns that works surprisingly well. Listening to my little compressor in a closed garage is no fun, but there aren't many rivets left to pull. I also have a drill attachment that's supposed to pull rivets. I should dig that out and see if it works.

You'll pass me soon, Alex. I got a recall notice last week; I'm going back to work sometime in March.