#3 Wing Joiner Jig, Floor Wing Frame Jig & Fabric Search

Sorry for the disorganization of my reports....this info should have been in the very first post and begins with my retrieval of the trailer and glider/materials to my current home in Dallas, OR.

Tuesday, April 16, 2013

Went to Spiering's house in Banks and retrieved my EasyRiser in it's trailer. Nostalgia! It towed like a dream all the way back (with about 300 lbs tongue weight!). Washed off the box and trailer then opened it up and pulled out all the parts. The notes/receipts showed that I had ordered supplies to repair it except for the material (1.4oz Dacron) and chemicals. Began the process of figuring out how to proceed.

Wednesday, 4-17-13

Got the damaged wing stripped of covering and figured out after some thought that I was going to need to cut all four flying wires (3/32 cable) which I did with a cut off blade and my angle grinder. Buy a Felco Cable Shears, you'll need it later anyway.  These shears are God-send when needing to cut cable.  It turned out that the rear spar was bent at the root so I proceeded to remove it as well as the leading edge spar. The root plugs (wing connectors) were both frozen and I ended up using the cutoff blade to get them off. I couldn't believe how little adhesion there was of the fabric to the aluminum. I plan to make a jig to hold an 8” length of tubing so that I can safely run it through the table saw to make a splice insert for both the leading and trailing edge spar joints at the tip end. Trying to layout and mark the new spar to exactly hit the old rivet holes is going to be difficult. I'll try it first and then make new ones if I think I need to. Got to decide on what materials to order and get the order in soon or I will be waiting for supplies to go any further. By the end of the day tomorrow, I expect to be very nearly ready to begin cleaning the frame for the upper left damaged wing.

Thursday, 4-18-13

Took out the right wing and set it up. I could barely attach the setup (neg. flying wires). Suspicious that it, too, was tweeked, I checked the rudder motion....it was binding noticeably and I think would not function to fly. I flipped the wing over and found myself looking at several significant holes in the covering caused during the crash....both upper and lower wing panels. I cut the flying wires and separated the two panels. I also noticed that ALL the diagonal struts are missing. There should be two for each wing...one at the tip and one at the root. I also remember there was fairing tape in the kit or at least I may have ordered it later for all the exposed struts, something UFM was making part of the kits. I have yet to find it. I measured the degree of bend in both upper and lower panels (trailing edge-TE and leading edge-LE). I did this without the diagonal struts in place but believe they would have made no difference in the measurements. Also, the bends were all consistent with what I expected would happen as a result of the known impact forces.

Things to do next:

1. Research covering process choices and order chemicals  (read plans and make a list).
2. Order the fabric (read the plans and get the amount right)
3. make both a LE and TE spar splice jig so you can cut these on the table saw
4. look into ordering a swaging pliers
5. start a blog for others to follow.

Friday, 4-19-13

Weighed the fabric found at the fabric shop shop near SE 122 and Powell in Portland which calculated to be ~1.5 oz/sq yd. Also weighed the old fabric from the kit which was also ~1.5 oz/yd. They looked nearly identical under my hand microscope. I placed the order for 45 yds of 48 inch wide white for approx $120 plus shipping. It was a generic liner material of 100% polyester.

Called and surfed the web to research what fabric glue to use and what prep the frame would need. Looks like there are two choices: either PolyFiber or nitrate dope. Ordered the Polyfiber process manual for $10 from Spencer Aircraft in WA.

OK, now that I've got that entry down we can continue where I left off with report #2.

I had a real scrub job to do on the LE & TE replacement spars I had ordered back in the late 70's to do the repair. They had been stored unprotected and had some corrosion and staining that I had to take off with 400 grit wet/dry sand paper. I researched covering process options and concluded I have three choices; 1) nitrate and butyrate dope (the Ceconite process), 2) the Stewart system which is a water-based proces and 3) the Polyfiber process which replaced the old Stits system and is solvent-based similar to the Ceconite process).   At this point I'm going to try the Polyfiber process on the left wing panels which have both already been stripped of covering.

   

The photo above shows the leading edge being treated with a chromic acid solution. This stuff is available from aircraft supply houses and is part of the Polyfiber process. As I understand it, you are actually “anodizing” the aluminum using a wet chemical process of dilute chromic acid. That's a drywall mud tray (stainless steel) and a $2 brush. I did about 2-3 ft at a time (7 minutes reaction time per section per EasyRiser original instruction plans). I made the mistake of joining the TE spar to the wing tip BEFORE doing this treatment and that made it really hard to complete the treatment. Treat all spars and struts BEFORE you assemble the to avoid this.

The next thing I needed to do was fabricate tubing joiners for both the LE and the TE (leading and trailing) edge spars where they are attached to the wing tip curved tubing. You cannot use the old ones because you would be drilling blind to hit the old holes.  Here's what I came up with;

I flipped this over and ran it through the blade on my little benchtop table saw after spraying the spar section with WD40 to help keep the aluminum from sticking to the blade. I used a Freud Non-Ferrous/Plastics 7 1/4” 56 tooth blade (about $40 at Home Depot). I estimated the slot needed to be about 3/16 wide so I had to make two passes. As you can see, the blade made it through the tubing before it passed through the end block on the jig which kept me from getting hit with aluminum shards (they're hot!). Did the same with the TE spar. Used the broken LE and bent TE for stock. I used this same blade on a small chop saw to make the 8” section required for the LE joiner (didn't have a pipe cutter big enough). Finished the cut with a hacksaw because the 7 ¼ blade couldn't get all the way through the tubing. I used coarse carbide paper to smooth the outside edges and corner of both joiners and then treated them both with chromic acid.

Here's the 1 ½ LE joiner after the cut.

Next, I assembled the wing frame onto the concrete floor in my garage. I used concrete screws and a concrete drill to attach firmly (didn't want to deal with accidently getting this frame kicked halfway through assembly. I used the original plan instructions (diagonal measurements) to get the frame exactly 10ft spacing and within 1/16^th inch on the chord width. Now both the LE and TE spars have been joined to the tip piece and riveted. The upper left panel is laying in place here ready for me to reform the bent gussets used to attach the root and diagonal struts.