Project 5 build thread

[Jez]

Just a thought here, what if you had put a solid steel tube inside the rudder pedal T bar whilst welding those gussets on? It would have been impossible to bend then.

[Jez]

I've learned that a feature of this forum is that you can't come back later and edit a post to add pics.
Since all my pics are taken with my phone and typing significant content isn't phone friendly I will post some pics now and then do another post with a real keyboard
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Just a thought here, what if you had put a solid steel tube inside the rudder pedal T bar whilst welding those gussets on? It would have been impossible to bend then. Or used the galvanised bar you had. And then push it out with a hydraulic press if it got a bit stuck.

[Jez]

Hi Alex, I am in the process of fitting my rudder pedals in, and have been reading your thread which I think is an absolute life saver for first time builders like myself who has zero experience. I have ordered a piece of steel tubing to put inside my rudder pedal tube to straighten like you did. Is there any chance it could compromise the weld without knowing? I put a straight edge on mine and the gap is 0.6mm which is what roughly 24 thou is it not? I think that’s enough to cause it to bind after torquing it down do you think so ?

Jez UK builder

[alexM]

Hi Alex, I am in the process of fitting my rudder pedals in, and have been reading your thread which I think is an absolute life saver for first time builders like myself who has zero experience. I have ordered a piece of steel tubing to put inside my rudder pedal tube to straighten like you did. Is there any chance it could compromise the weld without knowing?

Jez,
I saw your post earlier and was going to comment. In my limited experience, just clamping your rudder torque tubes to be straight isn't going to fix it. 4130 is some pretty amazing material, which is why they make bicycle frames out of it. It's going to need some over-bending to straighten it out. In my case I think what was more effective than anything was to grind ALL of the powder coating out of the inside of those outer torque tubes, and also all of the powder coating on the inner tube - just where the bearings come into contact. Yes, .6mm is .024" but if you think about it, it really doesn't matter what the tube does between the bearings, as long as it allows the bearings align and move freely at each end.

While I was temporarily frustrated at installing/removing/messing with it/re-installing (rinse, repeat) I was imagining a new design with a spherical bearing in one end which would eliminate all the messing around. But if you stick with it you'll get it to move freely at some point and that's just part of being a Kitfox builder.

[alexM]

Just a thought here, what if you had put a solid steel tube inside the rudder pedal T bar whilst welding those gussets on? It would have been impossible to bend then. Or used the galvanised bar you had. And then push it out with a hydraulic press if it got a bit stuck.

I think the galvanized bar would have been stuck for sure, and would have just caused more grief.

[rv9ralph]

To clear the inside of the tube (removing powder coat and other material) use a brake cylinder hone. It is the easiest way to do it. If you haven't heard of a brake cylinder hone (those under a certain age haven't rebuild a wheel brake cylinder), search Amazon for it.

[alexM]

Okay a quick update before I head to the hangar. I'm loving the new job and (almost as importantly) I love the two weeks off every month. So far I have taken the first week back to do absolutely nothing, enjoying the time with my significant other (floating aimlessly on the lake, enjoying the sunshine, teaching her to shoot, etc). Working two weeks straight I lose track of what day it is (because it doesn't matter) and being home it still doesn't matter. I'm okay with that.

I should be at Hood River right now but I didn't have time to do a proper gear swing on the Yak, so rather than hustle I'm just going to work on the Kitfox and worry about Hood River next year. The Yak doesn't have jack points. It just has some red square outlines near the wing roots where you lift straight up with flat pads (read: plywood). Then you restrain the tail because there is considerable inertia/CG change when the gear moves - especially when you blow it down with the backup air system that has no restriction orifices in the lines. Should be a hoot.

I got my interior from Kitfox! Not that I'm ready for it yet but it sure looks great when I throw it in the plane.
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I did not buy the entire set since I'm trying to squeeze every ounce (and dime when possible) out of the plane. Obviously I got the seat cushions. I also got the main carpet pieces, the fuel line covers and the piece for the glare shield. Since I went with the bed liner I'm not putting anything else on the seat pan. I'm also not putting anything on the center console. The carpet is a concession because I needed to do something to protect the floor from where your heels rest and also takes care of the stick boots. The carpet pieces come up to a little less than 3 pounds. I could probably shave some ounces going a different way but they really do look nice.

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Another acquisition was this AC TrackTech electric r/c tug for moving the Yak and its (yet undisclosed) hangar mate. These things allow you to maneuver the plane within inches of hangar walls and each other while allowing you to stand anywhere you need to. No assistant needed. No shouting, arm waving, #$%& tow bars, hopping on and off the tug, crunching sounds or anyone else to blame. I saw them at the aviation trade show a few years back and vowed to have one. A couple of my hangar neighbors have bought them for their C180/C195 and they love them. Downside: They are not cheap. Looking back I realized that I have owned several very cool motorcycles and all but one of them cost less than this thing. But as the owner of the company told me when I talked to him at the trade show said, "It's cheaper than hitting the hangar wall, even once".

Now, off to the hangar. Geek is getting too far ahead of me so it's time to get busy.

[Geek]

Now, off to the hangar. Geek is getting too far ahead of me so it's time to get busy.

You’re safe Alex. Hanging out with my fellow Naval aviators and my H-60R pilot daughter. No work getting done

Geek

[Jez]

All the work Eric is doing on his Barn Find are making me feel like I'm not getting anything done. I have blown through my early December goal of having the fuselage ready (enough) to cover so I could start on my wings. Time to get a move on.

Last night I brushed the first coat of epoxy varnish on the vertical fin ribs. I read up very carefully about mixing the resin and catalyst, letting it cook (the EAA article said 45 minutes or even an hour especially if it's humid), filtering, reducing, etc.

Then, like a complete dumb ass I promptly mixed up two parts of reducer and 1 part catalyst. Gotta read those darn labels apparently. Thankfully I read someone else's post here a while back that mentioned it was basically the same as epoxy primer, and I noticed it didn't smell "hot" enough. I figured out the mistake (ie, reading is fundamental) and started over with better organization.

I had read about others finding drips when it was all done. So I started on the top rib and worked my way down, using an old towel draped across the rib under it (and therefore all the other ribs below) I varnished the underside and then the top side, then back under to mitigate pending drips. I caught several drips in the towel that way and only had a few when all was said and done.

Because it was both cold and humid I had let the catalyzed varnish cook for the full hour. I could tell towards the end that it was beginning to thicken, so next time I'll only let it cook for 45 minutes. I did get it all done while it still brushed on thin and flowed well. The EAA article says to wait two days, sand it and make the second coat. Today it was still slightly tacky in places so that's probably great advice. Rushing it would just make a sticky mess and waste sandpaper.

I forgot to mention that I removed the tail surfaces last night. It provided much better access to the rest of the ribs below the horizontal stab, and removing them was on the list anyway. I also needed to complete the body/fender work up top, at the gap between the vertical fin and the rudder.
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Today I took the horizontal stab and elevator out in bright sunlight on my saw horses and sanded the balsa/Superfil to transform from crude to rough shape. It was obvious it would need another layer of Smurf poo so I mixed up a small batch and slathered it on. That has to cure for a day before I can shape it. I expect it to be pretty close but not flawless at that point. The outer layer will be Hysol, and then finish sanded.

It was about that time I realized that I blew the sequence. I had put varnish on the rib which serves as the top of the access panels, but I had not yet bonded/riveted the angle which I had so carefully prepared. Since I have to sand before the next coat of varnish anyway, I'll just sand real well and bond/rivet.

I had fitted the bulkhead piece but had not yet created the angles for the forward edge or the short pieces at the lower rear corner. So today's attention was making those angles and fit/drill/cleco them.
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Anyone who has read the manual knows that access is expected to be difficult at the forward end of the longest rib, and at the top of that bulkhead. I positioned the rivets on the bulkhead angles for best advantage when it comes time to pop those rivets.
I was pleasantly surprised to find that the bulkhead could not only be inserted with angles pre-riveted - it actually slips in place even with Clecos installed!

I realized that drilling those short angles for the aft lower corner would have been smart to do on the bench, like everything else. Well that ship sailed. To drill the holes would require a 90 degree drill, and I didn't own one. So before dinner I ran down and did the Tim Allen Binford 9000 thing and bought a Milwaukee angle drill. I checked before dinner and it will work perfectly for the job.

In the next hour or so I have a batch of aluminum parts prepped for etch and alodine. Tomorrow I should be able to sand the first coat of varnish and get all this installed.

Hi again Jez here, I have just mixed my epoxy varnish 20 g of ev400 to 40 g of ev 410. Let it sit for 45 mins filtered it and mixed in 25% of reducer which was 15 g for the first two coats and then 50% reducer for the last coat. Is this what you done? Also, I got worried when I started to paint it on realised that there is MEK in the reducer that just loves to eat away at paint/powder coat. And as you know it’s pretty hard not to get any on the frame, especially on the horizontal stabiliser. What are your thoughts, am I worrying over nothing? I do appreciate the responses and info I get off you guys.

[alexM]

Hi again Jez here, I have just mixed my epoxy varnish 20 g of ev400 to 40 g of ev 410. Let it sit for 45 mins filtered it and mixed in 25% of reducer which was 15 g for the first two coats and then 50% reducer for the last coat. Is this what you done? Also, I got worried when I started to paint it on realised that there is MEK in the reducer that just loves to eat away at paint/powder coat. And as you know it’s pretty hard not to get any on the frame, especially on the horizontal stabiliser. What are your thoughts, am I worrying over nothing? I do appreciate the responses and info I get off you guys.

I don't recall it causing any powder coating to bubble up or otherwise be damaged. I tend to keep a rag with denatured alcohol handy and wipe up any drips as I go. I have missed a few and found them too late to do anything about them. It's annoying to make any mistakes but they won't be visible on the finished airplane so I have already gotten over them. If you've got someone who can follow behind you with the rag/alcohol it will turn out better. I have also done some temporary selective masking, peeling the tape off as soon as possible.