EAA Meeting #2

I ended up taking my VS rear spar to the meeting to have some of the other members look over my work. All in all its as it was expected. Some rivets look good, a few need to be redone (The ones closest to the bottom brackets). One member has suggested bucking the rivets rather than sqeezing or using the back rivet set. He said that bucking them would allow me to get a whole lot closer. He was very encouraging and mentioned that it takes a while to develop the skills. He said that often folks will end up redoing their entire empennage at the very end of the project because their skills have improved so much by the time they get through the wings. I suppose I just have to chug away at it. if it works...great. If not, Oh well.

Started to Rivet the VS Spar - 3 hours

Frustration!! I started to rivet the VS rear spar today. Things did not go as well as I hoped.

I ended up having real issues with getting rivets set with the squeezer. Many of my rivets on the brackets where folding over! I'd drill them out, only to have it happen again. I find drilling out rivets extremely nerve racking as there is such little room for error. The easier part for me is to drill the machined head, but getting the shop head and the rivet shaft out is really tough without scraping the work underneath. I also found it extremely difficult to set the rivets that are located at the bottom brackets as the rivets are extremely close to the vertical portions of the bracket. After some time, i noticed that some of my troubles came as I was using the rivets as called out on the plans. Many of them were just slightly over the 1.5 dia rule of thumb and I noticed that if I trimmed them down ever so slightly with the rivet cutter (So that they fit perfectly with the rivet guage) my chances of successfully setting them with the squeezer dramatically improved.  I decided to stop for the night and get some opinions at the EAA meeting tomorrow.

Riveted Stiffeners to Rudder - 3.5 hours

I started in on back riveting the stiffeners onto the rudder skins. It took me a little time to get the hang of it and had to drill some of the rivets out. It always seemed like the rivets at the end were a bit tough to get right. I used some Dow Corning #3145 RTV (Clear) on the last part of the stiffener at the trailing edge. Drilling the rivets out went extremely well, however i was a tad bit concerned geting the aluminum pieces that I drilled out on the ends where I used RTV. I was careful to wipe the excess RTV off so that it would not interfere with the trailing edge piece. But in the end everything turned out well and by the third or fourth stiffener I was rockin and rollin.

Sky Combat Ace

I actually logged some time in an Extra 330LX. All of about 10min total it was still an incredible experience. Sky Combat Ace was really excellent (A bit pricy) but worth every penny in my mind. We took off from Henderson Executive Airport and headed south. From there we did three sessions of dog fighting. I scored two kills but lost one. We then did some acrobatics where the pilot did one, and then I repeated the maneuver. We did Loops, Barrel Rolls, Aileron Rolls, and Hammerheads. The pilot did an acrobatic tumble and then we did some low level flying. Totally awesome!

Dimpled Rudder Skins - 1 hour

Again...pretty wore out from work today and tired. So I just puttered away in the garage and set to dimple the rudder skins. At first I set the dimples so they were pointing up in the press but found out that the point on the die can scratch the skin (Darn) so the other side of the skin, I flipped it around. Much better.

Dimpling stiffeners - 1 hour

Unfortunately, I didn't seem to have a lot of energy to putting hours into the build. Work is really busy and taking a lot out of me. I managed to dimple the rudder stiffeners. My standard dies don't clear the radius of the stiffener, but after a little head scratching, I used my 3/32" tight fir dimpling die from Cleveland tool in the press, which worked out very well.  I ended up putting another order into cleveland tool for the small diameter dimple dies, as well as a screw on mandrel that I am missing for deburring operations. I also put an order in to Aircraft Spruce for some Dow Corning RVT #3145 clear. I thought about going Ultra Blue from Permatex, but I opted for the expensive stuff since I am applying it to my stiffeners and skins which are epoxy primed. 

Priming the Vertical Stabilizer and Rudder - 4 hours

I started priming the Vertical Stabilizer and Rudder today. After a bunch of reading on the forums, my priming tests and a quick discussion at the recent EAA meeting I had decided on a non alodine treatment. I figured just a straight 2 part epoxy primer would suffice. I do not live in a maritime environment so I figure that the maximum protection alodine would provide would be overkill for my needs. I settled on a good surface prep and then a 2 part epoxy primer. This morning I decided that I wanted to get a bunch of priming done on my parts before I go away next week. I picked up two big 50 gal containers from Lowes. I would use these to wash my parts.

Here is the priming process;

1. Parts are deburred and checked. Parts are gone through with a light scrubbing with scotchbrite red.

From this point on, all parts are handled with gloves on.

2. Just a few parts are washed thoroughly with water and Dawn detergent.

3. Those few parts are rinsed and scuffed with red scotchbrite in the water (gray scotchbrite for skins)

4. Parts are then dried with air and a clean microfibre cloth.

5. Everything is wiped down with Pro-Form wax and degreaser.

6. Everything is then wiped down with MEK.

7. Parts are primed with spray cans of Spray Max 2K primer

8. Repeat step 2 thru 7 for the next few parts.

I chose this process as it allowed the parts to be thoroughly cleaned and minimized the exposure of the newly scuffed layer of aluminum to oxygen before the primer is applied. It is fairly tedious, however with some good music playing time flys by and I can take comfort that I am at least getting the best surface prep that I think I am capable of.

The ugly side of the priming is that I do notice the increased weight of the 2K primer (Darn!!). I am giving the skins a light coat with the emphasis being applied to areas of mating surfaces so hopefully I mitigate weight as much as I can with the primer. The benefit of the 2K primer is that it is extremely tough so it will offer a level of protection when I get into riveting.

At the end of the day, I know I will be penalized for weight on the priming....however I intend to shave some weight in other areas (i.e. VFR Glass EFIS instrumentation, LED lighting, Beringer brakes and wheels, Fixed pitch propeller, etc) so hopefully things will balance out in the end.

As a side note....Its taken just over 2 full cans of primer to do the Rudder skins and the VS assembly. There's not much in a can. Ouch...that's an expensive method of priming. I estimate that it will take another 3 or 4 cans to complete the empennage. Also....it oversprays like crazy. Gets cloudy quickly in the garage when I spray!