Horizontal Stabilizer April 18 & 19

April 18 & 19

Horizontal Stabilizer

One day Im gonna realize how much time it takes to get things done! I set the HS skins into the jigs that I made and then riveted the nose ribs that I already installed in the skins to the front spar and then started working on the riveting the skins to the spar and ribs.

Once I started riveting the skins I noticed that I had the skins on the wrong sides! There is a line of rivet holes that i didn't countersink so a plastic fairing could be screwed into them in the future. Since I had the non counter sunk skins and ribs flipped from each other I decided to use the squeezer and flatten the countersink in the ribs to match the skin that was on each side.

This seemed to work fine, I just hope it didn't create micro-cracks in the rivet hole that will crack later in the future under the vibrations of a flying aircraft!

Now that I got that mistake "fixed" I am moving forward and riveting the skin. I started with the skins in the cradles on the floor and sat in my chair all hunched over working on shooting the rivets. This is less than ideal, my back was not happy about it.  i started riveting from the leading edge back, mostly so that the opening would stay large longer for me to get my arm into the part with the bucking bar.

After finishing 1 side of the HS I moved the part horizontal on my bench and used cardboard boxed to hold it up. This was a WAY better position to rivet in for my back. It did initially lead to more sloppy technique with my bucking bar causing it to dig into the primer a bit. Once I adjusted I was able to be more careful, the work flow also seemed to go faster in the orientation.

Done for the day, what I thought would take me 5 hours to rivet is now on hour 9 and I have 1 side of 1 half to rivet still. Mental note for the wings, they are going to take forever to rivet!

Horizontal Stabilizer 9.0 Hours

Horizontal Stabilizer April 17

April 17

Horizontal Stabilizer

Riveted the front and rear spar back together today, finally got back to where I was before I realized the paint job was off. Total time to fix that mistake on the Horizontal Stab 19.5 Hours! Not counting having to rebuild the rudder still, Oh well. At least Im making progress again!

One nice thing is I think I finally figured out this squeezer! I have to squeeze the rivets in a 2 step process. I set the tool to the recommended gap and squeeze everything of the same size, then come back after adjusting the gap smaller and setting the rivets to the final size. I've also turned the air pressure up from the tank to around 115psi which seems to help too. Its a little disappointing it wont set rivets in 1 go but its nice that I got it works now so Im not hammering all he rivets and risking damaging the parts with poor technique holding my bucking bar.

It is nice how uniformed the squeezer make the shop heads!

Finished the spars and started on new progress! Per the usual I thought this next step would be simple as squeezing the rivets together and the angles proved to make the center section much harder to assemble.

After finishing the center section I attached it ti the front spar along with the other ribs.

I then put the leading edge nose ribs into the skin and riveted. Theses I had to shoot with a gun and bucking bar. It took several attempts to get the most forward set correctly. Its very tight to get a bucking bar on it at the right angle.

All in this was a very productive day at the shop!

Horizontal Stabilizer 7.0 Hours

Horizontal Stabilizer April 16

April 16

Horizontal Stabilizer

Well its been some time but I finally got back to the shop. Yesterday I spend 2 hours cleaning the metal for paint prep and today I primed all the pieces, again, and dimpled all the parts for the CS rivets in the skin.

I really hope that I mixed primer correctly this time! I made 2 batches of 250g of Part A then 18% of that or 45g of Part B and then reduced it with water by 13% of Part a or 33g. I made sure to mix everything super well. The Part A was really thick almost like a paste when I first opened it, so I put my paint mixer in the drill press and let that spin for 10 mins. That seemed to to the trick!

I had emailed the company and asked what color they thought was the easiest to cover with a top coat and they recommended smoke grey for an all around option with not knowing what color topcoat I was going to be using. So Smoke grey it is now instead of the green I was using. The 2 part green color was very close to the CZ Green, but the single part just didn't look right, and after spraying the grey I do like the way it came out.

I am still very impatient when it comes to painting. I tried to be better this time spraying a Fog coat followed by a Wet coat. While I was waiting for the fog coat to tack up I cleaned up the shop and started to get the HS Skins ready for dimpling. This wored well for the 1 side, but then while I was giving the parts time to dry I dimpled everything I had to dimple flipped the parts and sprayed the other side. It was a little too soon and the the paint was stcking to the spray table. I need to spray 1 side and wait a few hours or overnight before I do the other side in the future. I just need to learn patience. Also, still need to get better at spraying in general. I was having issues getting the gun set correctly and was putting down uneven coats of primer.

I don't know why but I dimpled with the blue plastic still on, this was a mistake. I thought about it half what through the second skin and peeled the plastic off. I set a rivet into the dimples and the are definitely deeper from having the plastic between the dimple dies. Hopefully this doesn't cause a problem in the future when I am riveting the pieces together.

Horizontal Stabilizer 7 Hours

Horizontal Stabilizer March 15

March 15

Horizontal Stabilizer

Major mistake!!!!!  Oh man what a headache I created. If you remember back to when I first got the primer it had settled and the different parts had basically separated in the can and I had to mix and mix and mix and mix to get everything back into solution. Well, as it turns out the same thing happened to the catalyst! I put the stir stick into the can, but it is so small that when I thought it was at the bottom I really was riding on top of the settle out parts on the bottom 1/8'' of the can. So long story short everything I have primed with the 2 part primer will never cure and needs to be redone!!! To recap thats all the work on the Horizontal Stabilizer and the entire Rudder, I guess the forces my hand on rebuilding the rudder in the future. Oh well, what can you do but learn and move forward.

How did I realize this you ask, well I noticed that my primer job wasn't great and wanted to touch it up so i was scuff sanding the a part and used the etching spray to help with any of the metal the came though and all of the sudden this 2 part primer that was suppose to be solvent resistant started to come off!

So after looking into it and coming to the conclusion that the primer mix was bad I grabbed my drill gun and started removing rivets. After my freak out and ALOT of swearing naturally.

These drill stopped came in really handy, its not set in this picture, but I moved the drill bit so that I would only dill through the head of the rivet before the drill stop and I used the punch to pop the head off and punch out the tail. I started to get rather good at it by the end.

Ok everything is apart time to start stripping off the old primer. Simple enough but how do I do the longer spars?

Well I built a well and filled it with stripper to let the part soak and make my life easier.

It worked better than I expected!

Now I had to go back through with a rag and really press into the counter sunk holes to clean the primer out of them.

I also ran a reamer though every rivet hole to get as much primer as I could out of them.

In the end everything is cleaned back to bare metal! I did notice some pitting in the metal around where the rivet heads were and used my die grinder with Scotch-Brite pads to clean the metal up. The primer being waterborne I think really caused the metal to start to corrode fast with out the correct amount of catalyst, it was somewhere in here that I knew the rudder is going to be garbage in 2 years when the plane is done. Now I just have to redo all the work I undid and keep moving forward, after I get back from upgrade training!

Horizontal Stabilizer 8 Hours