Canopy Painting Completed

After proving yesterday that the fuel lines are liquid proof I focused on finishing the painting of the canopy parts this morning. We had a refreshingly cool day that was perfect for painting and I made good use of it. Within 3 hours (some parts needed their opposite side painted as well) I finished sanding, cleaning and painting of all the parts.
All that's left to get interior paint now is related to the fuel tank. I keep the paint booth for a little longer to see if I can at least paint the base cube in it to improve the paint job.


After painting I checked the temperature to be 80 degrees, exactly what we had last night when I last checked the pressure in my fluid filled test.


The pressure reading is exactly what it should have been. I drained the system as good as I could without turning the fuse on its belly again. I will try to hook up the return line and find a better matching hose for the two different fitting sizes or try to widen the clear hose under heat to make it slide of the bigger fitting of the supply line. I am not too worried about the return line through as the problems I had were all related to the NPT side of the fittings and the return line doesn't have any of these.

I guess I will start with the wiring now and leave the fuselage on its side for that.

Second Leak Fixed

The day started with spraying the white primer for the paint coat on the last stack of parts before the fuel tank. That was quickly done and the parts were left for drying.



Warning from the future!
Here I am traveling back in time from 2.5 years after I created this easter-egg to warn you NOT to follow my steps in how I tested the fuel system for leaks. While I was successful in finding and eliminating the leaks this way, I also created a serious problem in the fuel system that could have caused quite some more pain than it did in my case (which was luck alone!). 
The water in the system will cause the fuel pump to rust and decrease its performance significantly (or make it fail). This will lead to low fuel pressure issues on long WOT runs and will require a fuel pump replacement to fix (I am not sure if also the transducer might have been damaged by the water).
My suggestion is to use air alone at this point and to ensure that the temperature is the same when comparing PSI values from over-night runs. The alternative is to use actual gas but do recommend against it as it is too dangerous to mess with gas when there is a safer option.

Then it was back to the pressure test. The thread sealant should have had enough time over night to cure enough to withstand a few pounds.... I set everything back up again and set the pressure to around 7 psi. It didn't show an immediate drop so I let it alone and installed the servos for the autopilot.


That was kind of awkward to install first I thought I had to break my hand to get the servo in position with the pushrod already installed, then getting at the hex nuts to screw the servo in place was hard too. My hand seems a bit on the large side compared to the average Oregonian. I finally got all in only to realize I had forgotten to put the Loctite on. Argh! All out and back in. The second time was easier it appeared. Either my hand shrunk or I got used to the tight space. Anyway, I think installing the pushrod on the servo arm AFTER the servo has been installed would have been easier.

Back to checking the pressure.

Ouch!

It dropped half a pound while I was installing servo one. What the hell is this?

I pulled my soap water gun out and threatened those fittings but it didn't help. The leak must be a small one and hard to see with soap water. I used the flooding method and finally found another fitting that built up a foam collar although much slower and less impressive as the one I found yesterday. This time it was the forward fitting on the fuel valve. I drilled out the rivets holding the valve assembly to better work on it, removed the fitting and cleaned the threads as well as I could. Washed everything off with alcohol and smothered it with Rectorseal No.7 and put it back in. I gave it about 15 minutes to cure as I felt like I really had it with this cr*p. I pressure tested the valve assembly while still on the work bench and confirmed it was good to operating pressure of the fuel pump (about 5 psi). The difference was that I must have been worried about stripping the threads last time I put it in. Only the first 5 threads where in the valve and now I've screwed it almost completely in.
I put it back in the line but didn't want to give it my usual 8 psi test yet as the sealant was all fresh and I didn't want to blow it out with too early of a test. So I worked on the second servo.


(Comment from the past: You see this roll servo neatly installed at this point. DO NOT DO THIS! This is too early as it will prevent you from inserting the very long flaperon pushrods through that opening in the aft bulkhead that is blocked by the servo. Wait with this step until the pushrods are in place.)

Much easier to install although I don't know how to torque the forward two nuts. There's no way you can put a socket on them AND get a torque wrench connected to it. I torqued by feel instead.

Back to the pressure test. I filled the system with 8 psi and waited a little. I noticed a very small but noticeable drop.

Jeeeez!

What else can I do? Oh, I know! No more air! I need a liquid to see were it drips. I decided to hook up a small pump I have to fill the system with water (while the pump is on you have to push the gascolator drain to allow the air to escape).



Once the system is filled with water, I squeezed the water hose to stop the back bleeding and the I could add water through the Schrader valve to set it to the pressure desired. My gauge, Schrader valve assembly is above the water line, so this is the only part of the system that is not flooded.


Back to 8 psi again and waiting.

I went in the paint booth to check the parts and they were dry enough to get sanded with SB pads. So that's how I spent the waiting time, getting the parts ready for painting.

After half an hour I checked the gauge again.


I grabbed the work light and checked for leaks in the tunnel. Everything was perfectly dry. Not even moisture.
I sprayed the parts above the water line with soap again and couldn't see a blip. I checked the drain valve, not even moisture.
At this point I was considering selling the project.

Breath, Breath, Think!

I checked the water hose.


And there it was! A few drops of water were coming out of the large hose and resting on the clear line. As you can see I had a diameter issue here and no converters. This hose-in-a-hose thing with a clamp was all I could come up with. And that's were it leaked.
I clamped it a bit more and in different places and finally saw the bleeding stop and the pressure staying where it was.

Now the only unanswered question is: Why does it work with water but not with air? It looked like I had a very slow drop before doing the water test and I didn't have that hose hooked up then. I had a plug sitting on that end instead.

So was this test successful? Hm, I don't want fuel leaking into my plane. If I'd be flying with water I think I'd be good now. Unfortunately, that's not the case, is it?

Pressure Test Failed

I didn't get up as early as I had wanted to and so the early morning priming session had to wait. Just as well, as I had later found out that I hadn't really prepared all the parts correctly yet.
I started in the shop by cleaning and scuffing the parts I had missed and setting up the paint both to accommodate the large canopy frame, allowing me to walk around it when painting.


These are some of the parts that will get painted.

When this was all done the friendly USPS postman came by and dropped off the parts I had waited for from Aircraft Spruce to get the pressure test done. So, I quickly pulled the tarp off of the fuselage and set up the fittings to connect return and supply line at the tank area to pressure test the whole fuel line at once.
Oops, that didn't work out at all. The pressure I put in with a ball pump didn't even hold for a few seconds. And I was wondering if I could really hear a hissing sound or if this is a sign of developing a tinnitus... Well my ears are ok. It turned out the ball pump is so cheap it wouldn't hold pressure slowly leaking air unless you kept on pumping.
I removed the ball pump and hooked up the tire filler gauge to the compressor.
Ah, that was better!
Oh, wait, wasn't this 0.1 psi higher a moment ago?
Sure was!
So there was a leak! At least one, I should say ...

I used the fuel valve to shut off everything behind it but I till lost pressure. That could have meant that either the valve is leaking, or the leak is in front of the valve, or the valve doesn't perfectly shut off.

I first wanted to make sure my test setup was leaky itself, so I removed and tested the pressure gauge and Schrader valve assembly. It turned out to be perfectly sealed.

I didn't trust the valve and started removing flared tube connections one by one. Cleaning them, greasing them with fuel lube and putting them back on. Still a leak.
When I got to the valve I decided to stop and see if I can locate the leak with soapy water as I was starting to believe the valve did indeed cut off the aft line.

After cleaning the whole forward tunnel with soapy water I finally sprayed it on the fitting end of the aft connection of the fuel flow sensor. Aha! That's how a bubble bath in the making looks like. It was leaking not at the flared end but where the fitting screws into the sensor.

I removed the fitting, cleaned the threads as good as I could and put a thick layer of Rectorseal No. 7 on it and screw it back in. While I was doing that I was thinking that this could have all been easily avoided by getting the pressure test equipment before even starting on the fuel lines. That way I could have tested every component before putting it into the plane. Now I'm thinking about pressure testing the brake system before putting fluid in it as well!
I assumed that an immediate follow-up pressure test could jeopardize the seal and so I decided to stop there and let the sealant cure before I add pressure to the system again.

I went back to prep and prime and finished the priming part. I decided that the steel parts as well as the parts that get into contact with the elements should get primed green as that stuff is the better corrosion primer. This would include the flap handle, the flap guide assembly and the canopy and the canopy skirts.


After some two hours the stuff had turned green.


Somewhere in between, I forgot when, I also primed the servo pushrods. Because of that dreaded fuel line leak I didn't get to the installation of the servos today.

Servo Crimp

Didn't do a lot today but managed to crimp the wires on the servos.


With pushrods done as well I can now install them in the fuselage.
I hope to get up early tomorrow morning to escape the heat and get some prep and prime done on the remaining parts as well as the servo installation.

Almost forgot to mention that my plexiglass rear window arrived today. This will be fuel proof and the tint will help keeping the fuel cool.


And this is how it arrived here. Please notice the integrated carry handle!!!

Vacuumed a Thread

Again I did a million different things in as many different chapters. It's really hard to see any progress working like this. The reason is still that I couldn't complete the pressure test due to missing parts and this is holding me off from really starting the wiring section yet. So I try to stay busy picking up easy and limited tasks in preparation of other steps.
Tonight I worked on parts of the canopy that will hold the plexiglass in place on the sides of the canopy. These little angles will have to get painted, so I prepared them as much as I can at this point for getting the Sandlewood sprayed over it.


I marked the drill spots according to the instructions, pre-punched them and used the drill press to drill through them. Put some wood behind it as the metal is thin and could warp if the drill just sees air behind it.

The next step was some preparation for the actual wiring section. I had read on VAF that a lot of people spent hours to get the guide thread through the control stick to eventually pull the wire for the microphone switch through. It appears that the shape of the tube with a 90 degree turn and some additional obstruction in there and the sharp edges inside the control stick is catching on to the thread and preventing it from following the tube to its other end. People used lead bobs, and pressurized air to push the thread through. One guy suggested vacuuming the thread from the other end.
It works!
Here's my modified version.


I used an ordinary thread. Nothing slick or a nylon line or anything. On one end I attached a 100 grain .32 wadcutter bullet (just some plated lead I had in stock) by drilling a #40 hole through the bullet and tied the thread to it. The reason is that the thread could try to fall into the tube while I am painting it. The bullet is too big to pass the obstruction in the tube and so I can shake the bullet back out on the desired end and hopefully the thread will still be attached. To increase my chances of the thread being still attached I added some glue to the knot. The bullet also helps to prevent the thread getting sucked into the vacuum as the bullet can't pass the obstruction.
Then I put a few inches of the thread into the tube on the side where the mike switch will go and put the end of the vacuum cleaner on the other end and turn it to maximum power. The thread gets sucked in best if you obstruct the opening on the mike switch side with your thumb to increase the speed of the air in that area. When the bullet is about to get sucked in, STOP :-).
It might be that the thread is not hanging out of the lower end of the control stick at this point but it should be really close and probably caught up on one of the burrs inside the tube. Get some tweezers and pull the string out, Voila!
It took me 5 minutes on each stick to get that string sucked through and tape it to the tube.

With so much time left after finishing way ahead of average time on this task I started some prep work on the servo installation which will follow right after the wiring is completed. There is a small mechanical task in section 44 and that is manufacturing the pushrods for both servos. It's not really difficult but took a about an hour to finish it up. Cutting the tube lengths, deburring, pre-drilling, taping the rods on both ends and cleaning up the mess where the subtasks. I think the challenging part here is the pre-drilling as the tube is quite thin and a canted drill could probably render the piece as trash. So I used a technique learned in one of the earlier chapters. I used an undersized drill bit that just barely fir into the tube. In my case the best I had available was #12 bit. I used this to adjust the position of the tube in the drill press. Then I replaced the #12 with a #3 bit and drilled that side. Remove, replace, repeat until done. I think the holes turned out pretty good.


Finally I put the bearings in there as well and adjusted the pushrods to about the right length using the 1:1 drawing in the manual.



Now I am waiting for the missing parts to do the pressure test and the only other thing I might be able to do is some surface prep and to spray some primer and paint on the last parts.

Bakersealed

I just wanted to give a short update on the fuel pressure test that I wanted to perform yesterday. Well, it turned out that for one, I wouldn't have had to wait a day for the Bakerseal to dry as it wasn't at all dried after 24 hours. I assume that is supposed to stay that way and so I encourage you to just wipe excess amounts off as they'd end up on your fingers anyway if you don't
So I went ahead and flared the short pipe extension to connect the brass tee to the gascolator fuel supply nipple. That went well and also putting the cap on the return line nipple on the firewall. Unfortunately I then had to discover that my memory had fooled me on the hook-ups to the tank. There I wanted to attach a hose of some kind to short the return with the supply line and run a pressure test over both lines at the same time. Now, the ends of these tubes are flare and need fittings to allow a hose to connect and I hadn't ordered those fittings.

Grmbl!

So I put in another order with Aircraft Spruce in the faint hope of getting these parts before the long Memorial Day weekend. I used economy USPS First Class shipping so chances are I might get it on Saturday, as California is right around the corner.

Short Session

I just had an hour tonight to work in the shop. I assembled the pressure gauge with a tee and the Schrader valve and the fluid fitting that will connect the assembly to the gascolator. I used Bakerseal on the threads, so it will take a day to dry enough to withstand pressure. I probably can finish flaring the pipe for the gascolator connection tomorrow and setup the test pressure then.


And then I had a moment to rivet together the parts that comprise the flap handle base. I want to paint this once it's assembled and not the separate parts as it is easier that way.


Some countersinking had to be done here so the base would stand straight on a flat surface.

Fuel Line Pressure Test Coming Up

I spent the weekend with some light work of pulling and deburring the last parts for painting. Almost all were related to the canopy and the flap handle. I think I'll have two more paint sessions coming up. One with the canopy and flap handle parts and one for the fuel tank and related parts. Then I could tear the paint booth down and make room for the full length fuselage, so I'd have a place to store and work on the fuselage after the tailcone got attached.

Today I should receive the last parts to set up a pressure test for the already installed fuel lines, leaving out the tank. I'm a bit paranoid about fuel leaks in the plane but I guess this is a healthy attitude. The missing part is the Schrader valve and it is supposed to be in the mail when I get home. I have to manufacture a short piece of flared aluminum tubing connection but other than that I have it all in stock now. Hopefully I can set up the test tonight and have it sit over night to get a full 24 hour test done by tomorrow evening.
If this turns out to be good, I would start with the wiring.
By the way, I am now close to 700 hours of build time. including all the priming I decided to do. According to Van's build estimate I should be about done by now, which is realistic if I hadn't primed.

Window Gooped In

So, today I could work a day session as I was on night duty for tonight. Just as well to use some daylight to get the fuel window in. What a gooey job. I rehearsed the upcoming action for about half an hour before mixing the Pro-Seal. i wanted to be sure I had a feasible plan of action and ready to go when the clock started ticking for the pot life. I am glad I mixed a little more Pro-Seal than I thought that little area would need. I mixed 30 grams and I used it all up.
Yesterday night I did the deburring and scuffed up the flanges of the backplate and also the parts of the window that are critical for being leak-proof. That is the plastic where it would touch the aluminum around the large holes in the skin allowing to judge the fuel level and the area around the cutouts in the window where the screws hold the nuts on the plastic. I used a 1" SB deburring wheel on a die grinder until the plastic wasn't shiny anymore. My hope here is that this will allow the Pro-Seal to stick better to the surfaces and provide a better seal against leaking fuel.


The inside of the tank skin I had already scuffed good with a maroon SB pad a few days ago.
After all this prep work was done and the parts where thoroughly cleaned with isopropylic alcohol (that stuff is OK with the window plastic), it was time mix the Pro-Seal. I filled almost all of it in the syringe as usual.
The toothpick part I didn't do. I used a small spatula that Mickey D is giving away as coffee stirrers to apply a thin coat on the outside of the tank skin where those two initial screws are being put in to allow for holding the window and adjusting the backplate.
The holes for the screws in the tank skin are tight and I decided to leave them as is and drive the screws through with an electric screwdriver. My hope is that this tightness will help seal these holes. After the screws were in I started the sealing job. I laid a string of sealant from the syringe around the window holes, staying just inside the screw holes. Then I laid a second string around the window holes just outside of the screw holes. Then I put the window in and let it just sit on these strings.
Next was to squirt some sealant in those window cutout that allow for the screws to penetrate it. I filled all these cutouts with sealant before laying a string on the flanges of the backplate (this step was probably not necessary). I carefully put the backplate, making sure that the screws were coming through the correct holes in the backplate before letting it touch the plastic of the window. This worked out fine.
Then I put all the missing screws in there. I started them without putting sealant around the hole or under the head of the screw. Just drive them into the hole and leave them out about 1/8". Just enough to get some sealant pressed under the head with the syringe. Then use a manual driver and slowly screw it in until the head touches the skin. No problem here.
So far so good. Now it was getting messy. Those washers had to be put in place and therefore they had to get some sealant. I chose to not put the sealant on the washer and then put it on (I tried that twice, gross). I chose to squirt some sealant around the penetrating screw on the window and then set the washer into that turd of sealant. Your glove is going to get severely covered in sealant and you might have to change it frequently to maintain a grip on these little parts.
Next were the hex nuts. No escape here! I had to take every nut and squirt some sealant on them before starting them carefully on the threads if the screw. I think I had to change my glove about 3 times for the 22 nuts.
Then the nuts had to get tightened which I did with a 5/16" socket and a screwdriver. I held the screwdriver and used the socket to get the nut tightened. Just as Van's noted, I just set them finger tight. Why this is so important I'd love to understand but at this time it escapes me.
Finally I had a tiny bit of sealant left in the syringe and so I decided to clean the installation up. I put a nice seam around the window filling the ledge to the tank skin and then I put some sealant on top of the hex nuts where the screw penetrates.


And that was that. Now it's curing and it will take at least a week before I want to really test this with water and soap.
By the way, I had a little bit of sealant pressing through the window holes but not too much and I think once it's cured it will be easy to get it out and it might not even be visible after that.
The whole job took me two full hours, including planning the strategy.

The Fuel Window is Next...

So I had another little Pro-Seal session. This time I riveted the aft mount bracket on. For this task I had to squeeze 7 AD4 rivets. Pretty easy, despite the dark gray matter getting everywhere. I realized a few things today that you might want to consider when building yours.
1. If you decide to seal the outside perimeter of the nutplated ring which I did today, you want to do this before installing the front bulkhead to the main tank skin. Much easier to get at all sides with a syringe then.
2. When they instruct you to fill those 4 tooling holes in the baffles, do it before installing them. You can put blue tape over the stuff from both sides to hold the goop in place. If you don't, it's likely that the holes will open up again as the goop is following gravity.
3. Once you realize that you have a whole batch of Pro-Seal left when finishing your task, use it to fill up the corners good. Just fill the corners and then spread it slowly with the gloved free hand. When done, slowly move away from the corner following the skin and pressing down so you don't pull the Pro-Seal out of the corner again, opening up air holes.

Once you realize all that, the task is not so hard to do. Oh, just one more thing. To avoid spreading this black plague on every tool, have paper towels ready and an open bottle of isopropylic alcohol. This stuff is not dissolving the goop really well as acetone does but therefore it also doesn't dissolve the nitrile gloves as acetone does. With an old rag or paper towels you can really clean your gloves again and reduce the spread on tools.


Corner filled with a thick layer. Lost probably a quart of capacity right there :-)


Aft mount bracket installed. Don't let the reflection confuse you...


Baffle tooling holes and corners and the ring filled with goop.

Now the basic tank is done and the next step is to get the window in there. I've decided to give it one try and test the tank with the top off and water in it. I'll add some soap to reduce the surface tension and to help clean any contamination out.
If it doesn't work out I will take the window out and cover the fuel window holes up from the inside and outside with a thin skin.

Still Gooping On...

Second day on the Pro-Seal front. My is this stuff no fun to work with. The only thing I haven't noticed yet that was reported by others is the sulfuric smell. I guess that's because I am wearing a respirator the whole time I work with the stuff. As I am doing it in the shop due to the nicer, A/C'ed temperatures, I thought this might be a wise move and could help to avoid me dying before the plane is done.
I was using the whole two hours of pot life and almost finished the second page in this section. Riveting on the aft attach angle couldn't get done in time as it required some squeezed rivets and that would have taken more time than I had to stay within the two hours pot life.




The blue tape helps to keep the work bench clean after the rivets have been pulled and working on the aft side.
One big hiccup I have to report. On page 37-03 on the left bottom side they ask to put some washers under the shop side of the top rivets that hold baffles in the front and on the left side of the tank. That's an easy task to put these NAS1149FN432P washers on the rivet before squeezing, IF THEY HAD PROVIDED THEM!
It's not just that Van's had forgotten to put them in one of the gazillion bags of the Finish Kit but this washer type wasn't at all listed in the bags' content list. I was even smart while searching. I know that the NAS1149 type washer nomenclature has an old-style naming system in the AN960 nomenclature. I even looked that one up and found that an AN960-4 washer would be the old style name. Browsed the bags' content list again, no such washer. I found some AN960-4L which is the flatter version of this washer in the left overs from the Fuselage Kit. So I knew how they look like. I tried to find something close enough in my hardware boxes as I figured that this particular set of washers wouldn't need to be AN type hardware. They are just meant to spread the load a little over the flange when the sloshing fuel hits the baffles.
I decided to manufacture two washers from scrap aluminum as I couldn't find anything that was close enough to be used. One of the extra servo brackets that came with the recent servo kit had perfect holes punched into it and had just the right thickness and stiffness. I cut out a little square around the prepunched hole and then used pliers to hold the piece against the SB deburring wheel to get a good shape. I made them a little bit oval in shape to spread the load even better on the flange.
Sorry, forgot to take a photo :-( And now it's all gooped up on the actual flange.

This all happened in the afternoon after a nice lunch. In the morning I was a little late to do the paint (due to the rising temps) but it was still within limits and I took my chance. Looks real nice again. In the afternoon it was cured enough to dare opening the paint booth and I was really happy once again with the Stewart paint system.



Not much more to do for today.

Now I am thinking about the fuel window. I am really not sure if I want to have this thing and I might decide to use some scrap skin to just cover it up, inside and out.

All Gooped Up!

In the morning I started prepping the two turtle deck skins that I had forgotten to prep before. I let them dry in the already warming up morning (85 F) and then started the priming spree. I had a lot of skin area to cover and indeed ran out of primer in the process. i had to leave the booth and quickly set up some more primer to be able to finish the job without before the primer completely dried. So far I couldn't see any problem sin the finish.




If you look closely you can see the masked off area where the fuel neck will be mounted to the skin and which will get sealed off with Pro-Seal again. This time though they want you to put a release agent on the skin so you can remove the neck later (at least once a year for you annual). To avoid issues with the paint and the different chemicals I will be using I decided to mask off that mating area and allow the Pro-Seal to have contact with the bare aluminum instead of paint.

Once the priming was done and the parts were happily drying away, I went back to the shop (did I mention how much I love my A/C in the shop?) and prepared the first step of the goop-assisted assembly of the tank. Before that though I wanted to make sure that the perceived mismatch of the nutplated ring and the screw holes in the forward tank skin weren't presenting an unsurmountable issue when I finally will put the cover on. So I screwed the cover on first to see if a match and possible seal could get accomplished. Thumbs up on this one! One screw was a little hard to get in but with the help of Boelube that worked out anyway.


And then it was time to mix the goop and get ready for the action! Boy, what a mess!!! I mixed 30 grams of base compound plus 3 grams of activator and filled most of it in a syringe for controlled application. I put a spotted layer on the inside of the tank skin where it would mate the flanges of the front skin and the took care of the front skin flanges. I carefully put the front skin in, so that the short flange would mate with the main tank skin and aligning the side flange with the skin. That was easy to hold with one hand while the other was grasping for a cleco and them pliers. The first one is always the hardest in such a case but this one worked out ok. I started clecoing the side flange, then the bottom flange and the other side flange. I also gooped up the fitting for the tank drain and clecoed that in place as it shares holes with the other two parts.
Finding the right rivets would have been better done before I started this mess to save time. The standard B2 tank sealant just has a two hour window to work with. The riveting worked pretty well, usually just one slow pull with the large hand riveter and the stem broke clean off. Besides the sticky mess, really no problem. It was slow as I followed Van's advise to goop up the stem of every rivet before setting them.
Then I tried to use up the rest of the Pro-Seal at around an hour later. The stuff already got a bit thicker and harder to squeeze out the syringe. This time the front mount bracket should come on. I put sealant between the skin and the bracket just in case one rivet would leak a bit, clecoed and set rivets.
The countersunk rivets (I forgot their name right now) gave me trouble. Two of the stems broke off in the riveter. A look inside showed that they hadn't compressed that much, so I wonder if I should just goop them up from the inside now or go through the pain of drilling them out and trying again... Not sure what would increase the likelihood for a leak. No matter what I will do I'll first have to grind that stem down anyway, so maybe I worry about that later and take a closer look at the inside of the rivets again.
Whew, squeezing all these rivets manually as Van's was asking is quite a bit when you haven't done it in a while. It really took me almost the full two hours to complete the job. I had 15 minutes left that I used for the cleanup of this mess.
Sorry for the long text without any stage photos but there was no time to do that as well as my gloves always having some stocky Pro-Seal on them that I wouldn't want on the camera.


You can see the stems better in the following picture.


That concluded the afternoon session. For one the Pro-Seal had to cure before I could consider to continue and then I also wanted to get to my sister-in-law's birthday party. Happy Birthday, Flor!

And finally I didn't forget to look up a detail in the instructions that show how the front cover will eventually get put into place and hopefully seal the whole thing up. See, Dave, no cork ring!

Deburring, Deburring, and .... Deburring!

After Google blogger had a nervous breakdown yesterday and didn't allow anyone- including myself - to update their blogs, I am now going to pretend nothing had happened and I just did two days worth of work in one.

As the title implies, most of the work was really deburring. The fuel tank is a delicate piece of art and is therefore put as one of the last riveting jobs in the Van's work order. Probably assuming that by then the applicant had enough time to acquire build skills now desperately needed as well as an intrinsic understanding of the occasionally odd Oregonian instructions.
After reading through half of the instructions for the fuel tank in section 37, I can now honestly say that by then Van's also expects the builder to read between the lines and being capable of an almost telepathic understanding of build concepts. Which means that a lot of details in the instructions, you might have grown accustomed to, are now simply left out.
The exact moments when they require you to use sealant to avoid leakage of the tank are described in a generally entry note that is in bold font but in the actual step you can not expect to get another warning - although sometimes they choose to do it. This certainly does not imply that when they don't say it that you could leave out the sealant as this could lead to the previously described undesired leakage of the tank.
So, to shorten this up a bit, I needed a lot of time to think the whole thing through and understand where and how to apply sealant and how these steps could get combined to complete a series of tasks with one batch of tank sealant. I also peeked through every other available builder blog who already completed the tank and didn't complain about lost gallons of fuel.
After determining what to do and in what order, I came to the conclusion that the best way of doing this is to start by preparing all necessary parts. And this, as the title implied, is mainly done by extensive deburring, followed by deburring-style scuffing of the mating flanges and surfaces as well as scuffing the inside and outside of all rivet holes that penetrate the tank skin to allow the fuel sealant to get a good grip on the surfaces and not get washed away by fuel eventually.
For all this I was using the small 1" Scotchbrite wheel on a die grinder and a maroon SB pad for some manual action. To complete this step it took quite some time but I am now ready to build the forward part of the tank (and the other parts as soon as the goop, a.k.a. Pro-Seal, has cured enough).
This is the stack of prepared parts and skins:


Finally I also ended up doing the few riveting jobs that seem to not require gooping of the rivet shanks or anything else as these leakages will later be covered in a whole by a cover (which then will get gooped on).


The fit of the ring that got riveted onto that forward skin is horrible. I turned it endlessly and put it on when the deviation of the holes appeared to be minimal but I am still less than happy with it. Getting the screws through some of the slightly offset holes will require a lot of force. I hope I only have to do this once!
The ring has a got ring to skin fit on the inside of the large hole but it does show a 1/16" gap all around on the inside. I might fill that with Pro-Seal to reduce the chance of wash out around the screw seals.
I also finished the countersinking that was prep work for the forward tank mount bracket.


I also received and inventoried the wheel pants (my are they big compared to the ones for my RANS) and the Servo Kit (w/o AP74). And Stewart has also sent the third quart for completing the interior paint so I will be spraying some primer on the prepped tunnel panels that are sitting in the paint booth for some days.
Looks like this weekend is going to be a busy one...

New Toys!

After a weird odyssey of two packages from Van's being shipped around all over town by Fedex while ignoring my requests to have them hold the shipment at one of their downtown offices, I was finally able to intercept them and take them into custody before Fedex would just send them somewhere else.
The shipment contained the awaited Servo Kit (without the AP74 unit) and the wheel pants and fairings and some replacement rivets from all the drill-out fun I had some time before. I should say that I haven't unpacked it so far and that this information is only taken from the shipping statement. I came home very late last night and didn't not bother to unpack the boxes yet.
I guess I'll find out tonight if these statements are true. All that Fedex fuzz was created by Van's requesting an adult signature upon delivery. I guess this was caused by the relatively high value of this shipment. If they could have just dropped the boxes off I would have had them delivered last Friday ...

The Next Steps?

I just realized that I had forgotten to prep the turtledeck skins in yesterday's prepping session. I should probably do that before starting the big priming and painting session that will soon come up.
And while I was anticipating how much surface I will have to cover with paint something else occurred to me. It would probably be a wise thing to do if I'd not work on the wiring next but to build the fuel tank first - for many reasons.
For one it would delay the start of the wiring session and hopefully get me closer to the release of the SkyView option. There are a few things in the wiring step that I have already conceived as a subject to change due to the SkyView. For instance, you wouldn't run the static line all the way from the tailcone forward to the panel as the pressure detector will very likely sit in the tailcone where the D180's compass is sitting. But then you'll have to run the pitot tube all the way to the aft of the cockpit, etc..
So in short, delaying this section could help in not working yourself into a corner. And then there is the practical aspect of where to store what and when. The space in the carport that is currently occupied by the paint booth is where I wanted to keep the fuselage once it is connected to the tailcone. This is where I wanted to work on the canopy and so on. So it would be really helpful if I could get the painting of the interior completed soon, so I could remove the booth before continuing with the build and ending up with a larger, bulkier structure that will need to go into that spot.
I am also nearing the expiration date of the ProSeal tube but that is certainly a minor issue and I kept it in the fridge the whole time, so I'm probably good even a few weeks beyond the date.
So, tonight I will look into what is required for the tank construction and start deburring the parts I guess.

Happy Anniversary!

Today is the 1-year anniversary of me squeezing the first rivet on the the RV-12 and I didn't forget it, although it was a close call :-).
The last days I have done only light duty as it is getting really hot right now and I am not adjusted to the heat yet. Yesterday we reached 100F I believe. It is incredibly dry though, so it is not too hard to survive this.
So, what happened in the last three days? Well after finishing the fuselage kit as far as I could and wanted to go at this time, I cleaned up the work shop a bit, found better storage for some parts that were always in the way and I started pulling parts from the Finish Kit. Separating the parts into Canopy, Tank and Fuselage categories, to know where is what and then putting them away again after being sorted into stacks and keeping the fuselage parts. The ones I was mainly interested are the ones that will require painting, to get this over with while the temperature range is still allowing it.
All the parts I found are the panels that will close up the tunnel and the big corrugated hatch that will close off the tail cone.


I put them in the plane first to get an idea how they will get arranged and to see how they looked. Pretty nice, eh?
Here's another close up of the forward area .


I decided to prep, prime and paint the visible side and to leave the other side alone. If there would really be some condensation and corrosion happening the part could always be thrown out and get replaced. I seriously doubt this will be necessary though.


This is the stack of deburred and de-vinyled parts that I then also prepped. During the week I hope to prime and paint them - if I have enough paint to complete the job. I'll probably order one more quart tomorrow, as the inside of the canopy (behind the fiberglass skirt), the canopy frame and the fuel tank will have to get painted as well and I am sure I don't have enough for all that.

Then, yesterday, I decided to peek into Section 31 which is mainly focused on fitting the wings to the fuselage which I won't do at this time and before the tail cone is attached to the fuselage. But the first page dealt with the assembly of the pin stoppers that will make sure the wings stay in place, once installed. This I was able to do without any other requirements and so I did that. I haven't found a note about this on the forum but I had serious trouble to get the aluminum pins moving freely in their steel housings. I tried to clear off any burrs inside the steel tubes with a drill and I also had to scotchbrite the outside of the pins a lot until they were moving good enough to pass my quality control. Other than that the assembly was fairly simple.


And today I masked the pins and primed them with NAPA 7220. I will paint them along with the other parts to make sure the primer stays intact and avoid corrosion. The steel seems to be completely unprotected and so I'm worried these might start rusting once I leave Arizona with the RV-12.


Oh, and I closed those mystery holes that I had pointed out in my last post. Dave confirmed that he had closed these holes with rivets and re-reading the instructions in section 26 it became pretty clear that I misinterpreted the meaning of their "LP4-3 rivets typ." along with the arrows pointing to different parts but not those mystery holes.

Section 29 on Halt

The battery and oil can box had to be built and put in place on the firewall. The part is really well designed and incredibly strong yet lightweight once installed.


It was a little hard to get at some of the rivets but the CQR solved all of these issues.

The next step was to seal all the rivets on the firewall and I wanted to also touch the spots where the firewall sealant didn't perfectly seal the FW. So I started with an inspection of the FW and see if there were any other issue before starting the sealing.
Well, I found some mystery holes that did get any rivets yet and I feel this might be in error. Look at this:


These are just 2 of 4 holes in the front of these stiffeners that didn't get a rivet yet. I wonder why and if I maybe overlooked the instruction that told me to rivets them? Any hints are appreciated!!!

Then I started the sealing job. MIxed about 50 grams of ProSeal (ended up using about 30 grams in 1.5 hours) and filled in one of my plastic syringes and started sealing everything. I know you can't really tell on the FW but I show it to you anyway.


It's much better to see on the canopy ribs.


On the left...


... and on the right side.

While the ProSeal was curing I continued to build by manufacturing the little bent strip that will act as a retainer for the piano hinges holding on to the cowl.


Then I had to start a dimpling spree dimpling every rivet attach and screw hole on the top panel skin and the little angles that will hold the actual panel in place.


Oh, and before the top skin was dimpled there was this ominous instruction telling me to work the front of the skin by hand to bend it down slightly so once screwed on it would tightly fit to the top firewall stiffener. I really did this, carefully pressing the front of the skin over the edge of my workbench, holding down the aft with my other hand.
It worked and gave the skin just a slight trend to bend down. I don't know if that is why it looks really good when I screwed it down on the plane.


Then I ran into a serious problem. Installing those angles on the top of the aft of the skin and riveting them on should be done while the skin was bent close to its final shape. I could rivet the nutplates onto the angles in the shop but then the final installation looked like I should do on the plane. With my work bench at its current height that would have been a hairy task and sounded like no fun and maybe even some messed up rivets.
The only safe way of doing it was to be inside the plane! Finally!!! The reason I was waiting for to actually sit in the plane!


Feels great! Roomy for one, that's for sure. Don't know about two big guys in there, though. Ah well, there's always a -10 I could build if I feel cramped, right?


Sitting in the plane wasn't enough. I even had to resort to desperate measures and swap back to the manual riveter as the pneumatic one was just to heavy to work upside down on this flimsy surface.


And there she is with the panel top skin on. Beautiful!


Now if I only had a SkyView on order to fill this void!

Well, and the SkyView is the reason why I cannot finish Section 29 at this point and why it is on halt now. The next steps would be to install the map box and the other panel elements. On the photos I've seen so far all 3 panel elements are changed from what I have, even the one that takes the map box. So, to not do unnecessary work, I will just stop here and declare the Fuselage Kit to be completed for now.

The next step would be either test fitting the wings in Section 30 or to start the wiring in Section 31. I think, I'll go with the latter and start to dig into the wiring. As my servos should soon be here, I can integrate their installation with the other wiring stuff.