Saturday, July 2, 2016

Finished riveting and proseal of the rear baffle - 2 hours

Pretty self explanatory. I finished riveting the nutplates on the rear baffle of the fuel tank. After back riveting the nutplates I put a dollop of sealant on the heads. Much cleaner than when I first started on the tank access.

Monday, June 27, 2016

Aerobatic fuel pickup installation - 2.5 hours

I used a syringe to put a dollop of sealant on all the rivet exposed rivet heads on both left and right rib #1 and the shop heads of the tank attach angles.


Next I had tapped up the fittings on the aerobatic fuel pickups to ensure that no proseal whould get inside. I slathered up the fitting and installed them in the tank.

After a good cleaning in MEK I gooped up the area with proseal and torqued the AN924 jamnut on. I spread out the proseal on the nut, cleaned it up and applied a dollop of proseal to the exterior tank attach rivets.

 Next I used q-tips dipped in MEK and started the long process of cleaning proseal off the aluminum fitting threads. Some final wipes with the cloth and then I could remove the tape.




Sunday, June 26, 2016

Left rib #1 and tank attach angles - 6 hours

Big day today. I started the morning by installing the left rib #1. Once I had cleaned up the rib with MEK I had torqued the vent line to the rib fitting.

Next I needed to bend the opposite ends of the vent lines up to the high point of the tank. Took some  strength but I did it with use of my fingers to ensure that I didn't kink the line.

Both tanks are nearly done. All that is needed is to fit the tank attach angles. This part I am a bit worried about as in my mind it's going to be tricky.

Well straight off I can see that I will need to notch the attach angle to make room for the rivet shop heads. Little bit of grinding with the 3M wheel made short work of it.

Before I can set these in I needed some bucking partner help to arrive.

To kill some time I jumped over to the reinforcing ring on one baffle for the fuel sender. This is a bit tricky with the NAS nutplates as there is no room to get those rivets set. The squeezer was not going to work. After some head scratching I grabbed a back rivet set with a narrow collar and shaved down a side with the 3M wheel. It allowed me to make quick work of installing the nutplates by back riveting them.


  Well by the time I had that done, my friend mike arrived to lend me a hand on the attach angle installation.

He operated the gun and I operated the bucking bar. After coating all the pieces in a slathering of proseal. We set in to buck the rivets. Well...it went very well. Much better that I thought it would go.
 

Next on the agenda was to clean up the pieces so tomorrow I can install the fuel pickups.

Saturday, June 25, 2016

Right rib #1 - 3 hours

Well, I am on a roll. I see light at the end of the tunnel so I am excited to get through these tanks.
I prosealed the grommets on for the vent line, and stuffed some kleenex in the vent tube and slid it down the tank. I did this to ensure that no proseal would find it's way into the line. I remove the klennex and bingo. Vent line in.


After a good wipe down with MEK, I then slathered proseal on the rib #1 and the mating surface and cleco'd it together.

I was very careful not to get any sealant on the other vent line. Once all was clear I hand tightened the vent line in.

Then I went to town squeezing rivets. Once done, I cleaned up with MEK. Last item was to torque the vent line fitting at the rib.


Friday, June 24, 2016

Right rib # 7 - 3.5 hours



I managed to get a new quart of proseal this week from Van's. So now I can finish getting these tanks done and ready for pre-close inspection.
Finally done with the bucking rivets I was excited to get moving on to the end ribs which can be squeezed. Well for some reason, it wasn't entirely going my way. I had to drill out a number of rivets and re-squeeze. For some reason I was having a tough time getting the rivets to squeeze symmetrically, had a few that wanted to slump on me. Grrr!!! In the end I prevailed but it took more time than usual.


Sunday, June 19, 2016

Starting Flaps - 1.5 hours



Well I am out of proseal and waiting for more before I can continue on with the tanks. So next I decided to dive into the flaps. I used a file to remove all sear marks of the aluminum and then when to work with the 3M wheels. All ribs and spars have clean edges.  
 

Right rib #2 and misc sealing - 7 hours

Nothing like the day after a big airplane EAA/Fly-in to peak your motivation.

I laid into finishing riveting Rib #2 (the final rib to have bucked rivets). Rib #2 went in fairly well, again same as every rib, I had the odd rivet slightly 'cant' to the side on my while riveting. Here is what it typically looks like. (look at the second rivet in from the left)



Now a closeup.

The same rivet cleaned up

Well this simply won't do for me. So these I have been drilling out and re-bucking. I cannot nail down for 100% certainty what is causing the rivets to cant. I figure its a bit of combination of a few factors;

1 - I have dimpled the holes with tank dies. This results in a slightly deeper dimple and a slightly larger rivet hole. Which in my opinion aids to increase the chance of the rivet moving around a bit in the dimple.

2- Proseal. It acts as both a lubricant and a sticky medium. No question that it lets the gun/bar slip more easily when things are gooey, but it also has a stickiness to it. I suspect that when there is proseal on the bar/rivet tail. There is enough there to just pull the tail to one side when you are setting up to buck that particular rivet.

So basically on average I have been drilling out and re-bucking about 4 rivets per rib. Perhaps this may be more than the average builder...but in the end I am pleased with the end product. Its about on par with my leading edge riveting were no proseal is used.

In the end what personally worked for me (or greatly improve my chances of success) was to always clean the bucking bar and gun between each rivet set. I really think that this helped in reducing the change of a tail being pulled on initial setup. The disadvantage is that this adds lots of work and time to the session. But...Time is one thing I have and I sleep much better when I feel I have done the job right.

So...While I am talking about what worked and what didn't. I should probably summarize my thoughts and processes so far for the tanks. First off....the big debate of does a person proseal and cleco 24 hours prior to riveting? or do you wet set the rib (i.e. rivet right away). Well personally I intended to celco 24-hours prior to setting rivets after reading about it all on the forums.

But after discussion with some local builders....I switched over to the wet set method. Primary due to the reasoning that it greatly reduced the chance of pillowing the skin when bucking the rivets the next day. Although I am curious if bucking would have been easier with the 24 hour method. (no question that it is the cleaner method)

The biggest issue at first was to figure out method of applying proseal. Darin had lent me his Semco gun and I was fully intent on using it. I chose to use Popsicle sticks for the first rib just to get a feel for what I am up against, no sense in dirtying up the Semco gun straight out of the gate.  My first rib set was a huge eye opener. More in the time it takes me personally to set/rivet a rib in. I was surprised how quickly the proseal was setting up (I was using the 2 hour stuff) . Coupled with the fact that I needed to drill out and re buck the rivets that were canted, I just could not see myself doing more than one rib an evening. Well that started to rule out the use of the Semco gun. I dunno...Maybe I should just have used it anyway and bought a bunch of the syringes??? Oh well. Popsicle sticks worked despite it being messy. In the end I found that about 40 grams of proseal per rib did the trick.

I know this....I will be glad when I am done with proseal. It's not the worse thing, but I can't say I love it.

Well in any case. I set up to put the fuel markers on the inside of the right rib #7.


Almost to the end of the quart of proseal...I mixed up what was left and put a dollop of sealant on each rivet head of the right tank. A tedious process. No question the Semco gun would be a perfect fit for this task.

1 quart of proseal....gone. Need to order another.