Dimpling HS skins

November 5-6: I taped off the hole locations that remain open, and then dimpled the HS skins. Edge holes were done with the pneumatic squeezer, and the remainder with the c-frame and a hammer.

I clamped the HS cradles to the workbench and inserted the dimpled skins. The cradles were fabricated with plywood from the crate that the kit shipped in and some 2x2s from Lowes.

Then I clecoed the HS-905 nose ribs into place (two on each side), riveting will wait until tomorrow.

Riveting vertical stabilizer

November 4: riveted the VS skin to the skeleton. I wrapped the tungsten bucking bar in hockey tape to try to keep the scuffing to a minimum. Got it all completed in one session. All but the front two rivets on the VS-706 tip rib. There’s no room to get a squeezer or bucking bar in there, so it looks like I’ll have to fabricate something to be able to get those last two done.

And the rear spar is clecoed into place for now. Because Canada requires a pre-closing inspection, no parts of the structure can be enclosed beforehand. So I’ll have to leave the VS (among other parts) incomplete until I get enough done to have the inspector come out. This would probably include the VS, HS, possibly elevators and rudder, wing bottom skins and the bottom of the fuselage under the floor panels.

More Horizontal Stab and the Pneumatic Squeezer arrived.

So in the last post I mentioned that I needed to order a longeron or flange-nose yoke for my Main Squeeze squeezer from Cleaveland Tool. I got on their website Monday to order and realized that my arms and shoulders were still hurting from using the manual squeezer. So I took the plunge and bought their pneumatic squeezer kit. I emailed Mike and asked if they could substitute the flange-nose yoke for the 3″ yoke that comes standard with the kit, as I already had the yoke with my Main Squeeze. Mike emailed me back right away and said it was no problem. I completed the order with Annette, and everything arrived Wednesday. I’m 4 for 4 on great service by Mike, Annette and the rest of the crew at Cleaveland!

After getting things set up last night (Friday) I had a cinch job of finishing up the rest of the rivets in the front horizontal stabilizer spar thanks to the new squeezer. I’m looking forward to more rivets to squeeze.

I also countersunk the 400+ holes in both spars and the stringers and prepped both skins today with Prekote and maroon Scotchbrite. Prekote says to prime aluminum within 24 hours of prep, so I’ll warm up the garage first thing in the morning and prime the skins inside and out. And then use the leftover AKZO and a Q-Tip to touch up all the countersinks I made on the spars and stringers.

And my Amazon-provided torque wrench also arrived on Thursday, so I finished bolting the elevator center hinge bearing bracket onto the rear spar, then torque sealed it.

Moving the shop and assembling Horizontal Stabilizer

It’s starting to get too cold to spend a lot of time in the garage working, so we moved the two smaller EAA 1000 workbenches and assorted tools to the basement. I may leave the compressor in the garage due to noise and just run the air hose through the shared wall and into the basement.

I’ve been able to do all my structure riveting so far with my Cleaveland Main Squeeze, which has been worth every penny. BUT. I finally ran into a stopping point with the HS skeleton. The yoke that came with the squeezer is not suitable for riveting around the spar this time. So I’ll need to order a longeron yoke first thing Monday, which means I’m on hold with this portion until it arrives.

Still have plenty to work on, including deburring and priming the skins, and countersinking the two spars and stringers. Hope the weather cooperates for the priming.

Rudder assembly

September 23 and 29: Continuing on with assembling the rudder after priming.

Had another of what I thought was an “oops” moment when I saw that I placed the shop head of rivets on the rudder spar on the side of the thinner metal. I took pictures and emailed Vans support asking if I needed to drill these out and replace them.

Sterling replied that the manufactured/shop head standard is not mandatory, as universal head rivets have the same strength no matter the head orientation, and to build on.

Assembling VS

September 15: I was pleasantly surprised at how well the AKZO went on. It sprays easily, dries quickly so you can flip the parts and spray the other side, and cure hard as a rock.

Set the very first of tens of thousands of rivets today.

Due to the particulars of the Canadian amateur-built process, I cannot enclose any structure until an inspector from the MD-RA (Ministry of Transport) comes out to take a look at everything. As these inspections aren’t cheap, and they have to drive a couple of hours to get here, most builders wait until they have their empennage and wings nearly complete before scheduling.

This means for the vertical stabilizer, I will leave the rear spar unattached, but will rivet the rest of the structure and skin together. As for the rudder, I will have to give my assigned inspector a call as the rudder spar has lightening holes which will allow him access. But I will defer to his instructions.

Since winter is rapidly approaching, I’m trying to get as much priming done as possible while the weather cooperates, and then spending the winter months in the basement riveting everything together.

Priming first batch

September 14: Got all the parts for the vertical stabilizer and rudder prepped and ready for primer. I’ve waded through the primer wars for the four years I’ve been on Vansairforce.com, and I had primed my earlier RV-7 project with SEM self etching, which I discovered was not solvent resistant. So I decided to go with AKZO two-part epoxy primer. But I did choose to forego the etch and alodine steps that many others have promoted. I did like the idea of dipping clean parts into prep solutions, with minimal elbow grease required. But I wasn’t too keen on the logistics of disposal of acidic and hex chrome waste.

I prepped the parts of the RV-7 with Bon Ami and red Scotchbrite. But I found through the VAF forums and other builder’s logs that Prekote was an option to prep for primer. It seems to be just a glorified soap, at $40 per gallon, but it was non-hazardous and one step instead of multiple steps.

I chose a perfect late summer day to set up a plastic table in the driveway and get to work on all the parts. You have to spray the Prekote on, scrub with the Scotchbrite until you get a lather, spray again then scrub at 90 degrees to the first pass. Then you should get a water break free surface when you rinse. This indicates that the aluminum oxide layer has been broken. I had already built a spray platform from 1x6s and chicken wire, which I laid on a workbench and arranged all the parts on it.

For priming, I bought a cheap purple HVLP gun from Harbor Freight, which so far has done a great job.

And I know this will get gasps of horror from some builders, but I did research it on VAF, and decided to prime both sides of the skins with the AKZO. Other builders have gotten input from aircraft painters at some major airframe manufacturers, and they are fine with receiving an AKZO primed aircraft to finish paint. They wet-sand it then shoot their own primer that is compatible with the top coat. True, I will incur a weight penalty, but prefer having things protected inside and out, and especially at faying surfaces and lap joints.