First Full Day

Huge day today. This was my first, full project day of over 8 hours. It felt really good to get as much accomplished as I did today. I finished dimpling the horizontal stabilizer (HS) skins. I realized when I finished that I forgot a step in the directions! ARGH!! I hate when that happens! I deburred all the holes in the ribs and spars but forgot to hit the holes in the HS skins. Well, I checked them all and they felt/looked pretty good to me. There were a few that I hit with a debur tool to smooth 'em out. I smoothed all the other parts and even took them across the ScotchBrite (SB) wheel. I even found what appeared to be a little scuff/gouge on the edge of one of the skins. I took it to the SB wheel to remove the offending booger. It turned out ok. This won't be seen later as it is located next to the fuselage and will be covered with a cowling.

Cleanup on a Little Gouge on the HS Skin

The next step is cleaning all the surfaces for priming. I'm using acetone for the cleaning process. I can't seem to locate MEK (methyl ethyl ketone) at any of the DIY stores. Granted, I only checked the big two. It's a good solvent and even used as a plastics adhesive. I think businesses are replacing some solvents with other, safer products. I thought of using denatured alcohol but acetone works pretty well. I'm using gloves to protect my hands (don't want anyone commenting on the safety issues here). I should be using a respirator as well. I'll start using one. So, I got all the parts cleaned and re-marked where the acetone cleaned off the original, part markings. You'll need to make sure you do this so you don't go bonkers with mis-matched holes! You'll also want to make sure that if you can't remember the orientation of the part, take notes. Something like this: on a piece of paper, draw the orientation of the part, something obvious to you so you can't goof it up, e.g., up, down, forward, aft, inboard, or outboard and whether it is to be used on the left or right side. Then, clean the part everwhere the primer is to protect it. Now take your blue Sharpie (recommended by many as they seem to last longer) and mark the part again if you happened to clean the original markings off. I'm basically hanging all my parts from a wire and giving one light coat of primer then after 5-10 minutes, spraying a second heavier coat making sure to cover any exposed aluminum. I read the spray can initially but took particular notice the second time around of the notation about using 320 grit abrasive. This is supposed to prepare the area for better adhesion of the primer. I didn't do this step. I hope I'm ok with the way I've been priming. Of course, if you do this, the steps areas follows: 1) Shake can for 1 minute 2) use SEM solvent to clean the part 3) use 320 grit sandpaper 4) use SEM solvent to clean the part 5) spray 1-3 light coats 6-8" away from the part. That's a lot of steps and time. I'll give the fingernail scratch test to the parts I've primed later to see how they hold up. This primer, SEM, dries pretty quickly. The can says 15 minutes but I've been noticing the parts are drying sooner than that and seem to have a pretty tough coating.

Parts  Clean and Hung, Ready for Primer

Parts Primed with a Couples Coats. Looking Good!

I had forgotten to clean and prime a couple parts as I was ready to start assembling and realized that they were missing from the assembly batch. OOPS! So, I pulled them out, cleaned then primed them and waited for them to dry then I started to assemble them. That little missed step added an extra hour to the process.

Priming the Inside of the HS Skins

Inside Shot of the HS Skin

So, first you tape over a few of the rivet holes as you don't want to inadvertently rivet them without the parts being in place first. Otherwise, you'll be cussing yourself later. These holes are for the hinge brackets and ribs. First you'll rivet the HS-603PP rear spar and HS-609PP spar support bars together. Using the pneumatic rivet squeezer for this process is SO nice! It takes a few rivets to get the setting right on the squeezer for the perfectly set rivet. Next, rivet the HS-412 & -413 hinge brackets to the spar. The directions have me using an AN470AD4-5 rivet for the outboard hinge brackets. I set the first one and it was way too long in my opinion. I went down to a 4-4 and this seemed to be the ticket! so, I had to drill out a total of only 2 rivets. Not bad. I know, with a pneumatic squeezer, you shouldn't have this problem. Well, setting that 4-5 rivet leaned the shop head over (bent it). So, rivet drill-out #1. Then I found where a manufactured head didn't quite set flat. So, rivet drill-out #2. The rest went pretty smoothly. FYI - for the layperson, here's the 411 on a manufactured head and a shop head of a rivet. The manufactured head is the end of the rivet that has a head on it coming from the manufacturer (only one end of the rivet has a head on it before it's set. The shop head is what you end up with after you set a rivet, the mushroomed, flat head on the other end of the rivet when you're done setting it.

Lastly, I bolted the center hinge bearing assembly and torqued the bolts to between 20 and 25 in. lbs. Next is to start on the foward spar assembly.

Our Shop Worker In Process of Riveting

Half Riveted - Tape is NON-Rivet Holes (For Now)

Nice, Pretty Line of Rivets

Rear Spar Completed With Hinge Brackets

That's it for today my peeps. I'm pooped. Hmm, too pooped to peep! I'm getting punchy. Take Care and Thanks for Reading!

HOBBS Meter - 35.3 hrs