Closing Out Sections

Thanks to the timely arrival of another load of ProSeal, I was able to close out 3 open sections in the build manual that were in some way or another waiting for some sealant job to get done.
Before this weekend work started I was able to remove some more of the Blue Plague that was sticking to the tip of the right wing.

I forgot to take a picture when it was all off but it looks close to what you see above. Quite some scratching again, but nothing deep.

The last days were incredibly hot - even for Tucson. The monsoons are still not anywhere close and so it was a dry heat, and that's the only positive thing to say about it.

This was the sun setting on the last cooler days before the weekend, which is to say it only got to the lower hundreds.

Even the local animals (this one is a particularly young bunny that has not experienced another summer before) were struggling with this heat.
So I decided to get up before 5am each day to be able to get some work done outside without collapsing. Even then it was in the lower 80s.

It was time to mix the smelly ProSeal and get started on sealing the firewall - again. First a look at the beautiful sight of the installed engine.

Then I filled a syringe with ProSeal, in the hopes of making less of a mess, but as you can see, I still am not good at putting the stuff only where it is needed.

It worked much better on the side skins where I sealed the leftover rivet holes from the reinforcement angles. That is because I used blue tape with a slightly oversized hole punched into it as a template. After peeling the tape off I was left with a perfectly round seal.

I also sealed the rivet heads from riveting on the heater box. The manual did not ask for it but I do not understand why as these rivets are providing the same risk of letting gases from the engine seep into the cabin. Angles were too bad to get a shot at them though, so no photos.
This step completed section 54.

After the ProSeal task was done, I put the lower cowl on...

... (pretty, isn't it?)... and installed the SCAT hose, which completed section 49.

I also gooped up the penetration holes in the firewall that contain the cables and wires. I used red RTV for this and not the suggested firewall sealant. I was considering using the rest of the ProSeal but decided against it. If I ever need to pull a wire or want to add another one, removing the RTV would be easier than any of the other sealants. And this completed section 50.

The idea is now to leave the lower cowl on and to remove the instrument cover to finish up the pitot line plumbing. I will try to also install the Ts to plumb in the backup steam gauges at this point and then plug their ends. There is also a tad more wiring work to be done for the avionics which includes running the missing wire from the radio to the AV-50000 for the serial port.
Additional antennas for the PCAS, ADS-D and the APRS system that I will add are sitting in the shop and I think I might add those now as it will be easier to crawl into the tailcone without the tank installed.

Stiffener Kit Installed

Today the side skin stiffeners were to be installed. I started with marking the rivets on both sides that had to get removed.

In addition to the ones marked in the picture, there are also some on the sides of the firewall that have to get removed but I forgot to take a photo before I drilled them out.
Here is the "after" shot:

This one shows only two of the four rivets to be removed on that FW side. The next two are the ones under that goop (not visible) that right above, on the vertical part of the firewall, the drilled out aft rivet.
After you have removed these, you ought to draw line in the shelf between the two rivet holes.

This line will later be used to match-drill holes through the shelf into the stiffening angle underneath.
But first I had to remove the existing diagonal stiffener angle on the side skins. Van's asks you to cut off a portion that will interfere with the installation of the additional angle inside the fuselage. That's what they had you drill out the upper 3 rivets on the side. However, this approach appeared to be rather hard to turn into anything good. I foresaw the cutting wheel run off and gut into the painted skin and I could not even image how I was supposed to deburr that mess working under the instrument shelf.
So I decided to remove the angle completely, cut off the upper part with the bandsaw and correctly deburr it before riveting it back in place.

The upper 1" or so had to get removed on the side with the little fin.

No way I could have done this working under the shelf!
Reinstalling it did not take any time worth mentioning either.

Back to the instructions. I had to cleco the additional angle in place, check for clearance and proper alignment. Here you see why I had to cut off a part of the diagonal stiffener:

The aft end positioning in the above picture is not perfect. When I drilled the first hole I pushed the angle up a bit before drilling and it turned out just as requested.

I used my iPhone for these inside shots as it is easier to handle than a full-blown bulky camera. After the angle was properly aligned, the rest of the holes were match-drilled from the inside through the skin and clecoed.

This is how it looked on the inside.

But that is not all yet. I had to extend the line of rivet holes on the side skin with a marker to extend all the way to the front end. The hole spacing was 1" so I made my marks, pre-punched and drilled the holes into the angle. This time from the outside. After that the angle gets removed for deburring.

I decided to prime the forward part of the angle that would contact the stainless steel of the firewall shelf. The rest of the possible contact surfaces is painted so I did not bother.

While the primer was drying, I moved on to the right side and removed the diagonal angle.

The fin was quickly removed and the angle deburred and reinstalled. The additional stiffener angle was installed and aligned and the aft most hole match-drilled.

I should have given the iPhone more time focus before taking the shot but you can still see the proper alignment with the existing rivet. All the match drilling followed and this time I did not forget to take a photo after marking the hole line extension and doing the pre-punching.

All went out for deburring and priming again. While the primer on the right angle was drying I started riveting in the left side stiffener.

No surprises while riveting. Some of the rivets are hard to get too though. You do need the close quarter riveter as well as a wedge tool to do a good job. I should have mentioned that you need a 12" #30 drill bit to drill out some of the rivets on the shelf. Those are the same ones that need special care during riveting as you probably guessed.
Once the left side was done I declared the primer for the right side dry enough and installed that one as well.
Again, no surprises.

From the inside the stiffener looks like this:

It is recessed so far that I also did not bother painting it to match the interior. You can hardly notice this thing.
All in all, the stiffener kit took me 7.5 hours to complete. Not a big deal but I also did not have to remove the lower cowl as it was already off. And I am not fully done yet as I need to get some additional Pro-Seal to cover up the newly installed rivet heads.

Front Stiffener Installed

Removing the gascolator bowl and the cushioned clamp was  up next in the endeavor of installing the stiffener kit. The clamp was easy but the gascolator put up a fight. I had never before removed the bowl  which now turned out to be a big disadvantage as I could not see what held it in place after I had removed those 4 screws and the brace that held it in place. I pulled and wiggled but it would not want to come out.
After minutes of careful but consistent turning, pulling and cursing, it finally started sliding just a bit.
When it came out I could see what had held it in place.

Van's had applied the fuel-resistant lubricant quite deliberately and that stuff is sticky like something!
Inside the gascolator there is really nothing that could otherwise hold the bowl in place as this view shows.

Finally, I had the room to get to the rivet that had to get drilled out.

Well, right behind that hose that is. Drilling this rivet out was anything but easy, though! As soon as the spinning drill bit hit the head of the rivet the sucker started spinning like crazy and the drill did not dig into it. Any attempts to clamp something to the shop head side of the rivet were futile because the fuel line and the rudder horns and cables prevented me from getting any tool attached to it. A helping hand was also not in sight and I could not grow my arms to the required length to hold the drill bit onto the rivet head and hold the shop head side with a pair of pliers at the same time.
I resorted to the Dremel tool to grind  the manufactured head right off. That was fairly easy and safe todo as the only soft aluminum was the head itself and that was also the material I intended to remove. The hard steel around it would not easily get scratched by the grinder.
It did work out I was able to remove this nasty rivet.

You can clearly see the marks from the spinning head! You can also see that screwing out the head near the rivet head was not required to remove the rivet. However, I learned later that it is required to get a cleco in that position which otherwise would not get seated. So still no short-cuts for the instructions! Just do what Van's asks you to do...
Now I was able to get the stiffener angle clecoed in place.

See how this bolt had to get unscrewed to allow the cleco to pass?

The counterpart of the clecoed hole was drilled on the upper end of the stiffener.

The alignment of the stiffener looked good too.

The center holes were up next for drilling.

An almost clean ride followed until I was almost done and noticed that my oil canister was sitting too low to allow the drill to stay perpendicular to the surface of the firewall. I loosened the nuts a bit to allow to slide it up somewhat.

Then it was smooth sailing towards the finish line.

Now everything had to come off and get deburred. The angle was easy but the backside of the firewall was a different and unpleasant story. The rudder pedals are in the way and that is on top of the gross inaccessibility of that foot room area anyway. I cut my fingertips quite a few times sensing for those burrs while I wasn't able to even look at the holes at the same time. Eventually I was satisfied with the deburring and the riveting followed. That was uneventful after I had cleared out any obstacles during the drilling phase. However, some of the holes where only accessible with the manual rivet puller - to make this task a bit more exciting, I guess.

Here is the end result of the front stiffener installation:

I also reinstalled the bowl and the clamp, which is the last step in the instructions, so I jumped ahead in that sense. I did not see why the bowl should not get put back in place at this point as I can still get to all the rivet heads for the final ProSeal sealing.

One thing stood out though:

Obviously, the coolant overflow hose will touch the sharp angle and I will put a protection around it in that place to prevent a cut above the cowl surface.

Something you could not see in the pictures is that the firewall was indeed bulging inside over its full surface. When I held the angle to it when drilling the first hole you could clearly see that. Now the angle has pulled the firewall out and straightened it up. 

Stiffener Spacer Riveted

I did not have much time to night but I was able to rivet the spacer parts onto the stiffener angle.

Clecoed and done.

I realized a bit later that I had used ordinary NAPA primer and not the stuff for engine enamel. I guess that in between two good heat conductors this should stay cool enough to cause an issue.
A closer inspection of the following steps and the access for removal of the one rivet below the gascolator revealed that there will be no short-cut. I will have to remove the bolt that holds the clamp for the cooler hose and also the gascolator bowl to get to all the holes and to remove that one rivet.