Project Update

Hey Guys,

I left my last project update for a while so everyone would have a good chance to read it.  

So this is it folks!  I hope for this to be the final push from now until Rough River to get the main assembly of the aircraft completed.  That’s my goal.  Is it an aggressive timeline?!  Oh, yeah!  After Rough River, I then expect the next few months to be finalizing any leftover punch list items and the finishing & painting! 

Over the past few months I’ve had some unexpected scope creep in my build, which is all well and good because the build is THE project.  As you know I rewickered Marc Zeitlin’s new AEX system which took a fair amount of time to implement, then I had planned on knocking out a good dozen electrical related items so that I could close up the nose.  I got a bunch of those completed, but kept finding myself not being able to really close out wire runs, confirm install spacing configurations such as the pitch trim unit, etc. because I couldn’t sit in the airplane and confirm what I had dimensionally without the actual pilot’s seat in place.

This drove me to move my immediate project line of demarcation from the instrument panel, back one more bulkhead to the pilot’s seat.  I was then going to knock out the pilot’s seat area –including the thigh support & cover– but there was a glaring prerequisite to doing so: I couldn’t get the pilot’s thigh support configured & installed without the fuel lines in place!  Thus, I needed to move the project line of demarcation back one more bulkhead and knock out the thigh support sump tank to get the fuel lines run in reality without merely estimating some more with a fake, mocked up install.  

So the immediate order of battle right now is to finish the fuel sump (including configuring the majority of the back seat area), and then the pilot’s seat area. These, in turn, will allow me to finalize the configuration of the nose components. At which point I will focus on the building the nose while concurrently finalizing the wheel pants install (nope, haven’t forgot about those!). Then the canopy install will be after that.

Hang on to your hats folks, it’s about to get busy all up in here!

Cheers!

 

Chapter 21/22 – Sump glassing done!

Today I started out by cutting a small wedge of Kevlar to place over and around the sump’s front corner edge Nylaflow conduit.  I wanted to make sure that when the GIB steps into & out of the back seat that the Nylaflow conduit doesn’t get damaged.

I then cut the 2nd ply of BID to get laid up over the first ply of sump LE BID and the new piece of Kevlar.  I then wetted out the BID in place on the sump & then peel plied it after the layup was complete.

I had to make a Harbor Freight run, so after a number of hours I pulled the peel ply and cleaned up the sump front edge Nylaflow covering layup.  This is what the GIB back seat area is looking like these days.  With that last layup I’m done with fiber-glassing on the thigh support fuel sump, unless something new pops up of course.

I then set my sights on the oil heating system.  After inspecting the heat exchanger, I realized I could simply pop off the plastic protective runners on each side.  It didn’t take long looking at the heat exchanger to realize that my airflow in, through and out the heat exchanger was going to take place via the long sides of the unit.

I then cut some 2″ wide cardboard strips out to represent the width, albeit not the depth (which is 0.75″) of the heating & fresh air ducts.  I played around with this whole setup for a good 45 minutes before determining what my next steps will be.  Since there’s no exact plans for building the ductwork for the heating and fresh air system, this will be a bit more slow in the creation and build of this whole thing.  Plus, I got some good data points today and will continue to press on with building the oil heat system over the next 2-3 weeks.

I was also finally able to get the sump low fuel level sensor wires soldered tonight.  Since these are very low current sensors I’m using 24 AWG wiring for the leads that will traverse through the front sump wall Nylaflow conduits up to the Triparagon, where they’ll connect to power, ground and EFIS data input.

Here is the initial splice of the red wire of the left sensor.

And immediately after I soldered the wires together.

Here’s the blue wire soldered . . .

And all the sensor wires cut shorter and solder-spliced in this pic.

I also did the same process for the right sump tank’s low fuel level sensor.  Tomorrow I’ll heat shrink all the splices to finish up this task.

I also trimmed the edges of the sump low fuel level sensor protective covers as well, but failed to get a pic of them after they were trimmed up.  Tomorrow I’ll add a pic of the trimmed covers.  I’ll also continue working getting the sump low fuel level sensors installed and under the protective covers while concurrently working the oil heating and fresh air intake system.

 

 

Chapter 18/21/22 – Atonement!

For past sins!

I realized as I was making up a quick sketch of all the GIB controlled electrical components (with the addition of the LED lit fuel site gauges) that I should account for the canopy locking rod & latches.  I stumbled upon a discovery that shows yet another faulty assumption on my part, and I’m not sure exactly how I missed it.

The bottom line is that I found that the midpoint canopy latch is supposed to be –as per plans– situated at the front business area of my roll bar.  I played around with it for a while, but realized I just had to bite the bullet and will have to move the middle canopy latch about 1.4″ forward.  I’ll probably adjust the aft latch a hair forward as well, but at least now I know.  Amazing that just this nth order affect took me about an hour to track down (well, technically over 2 years to track down!).

I then decided to do something different for a bit, other than fiberglass, so I sat down for a good 45 minutes and swapped out my Andair fuel selector valve’s straight fittings for the 90° fittings I ordered a while back.

There’s no real directions as far as torque specs or anything on mounting these 90° fittings, so I just dove right in after checking Andair’s website and any available documentation I could get my hands on.  It take a bit of an oomph to get the straight fitting off & out of the fuel selector valve once I removed the screws, especially since I was being a bit cautious with this first one.

I then put the new 90° fitting in place and it fit perfectly.  As you can see by the tools I added into each pic, the original screws were hi-torq screws, while the new 90° fittings came with an allen key for mounting the new screws.

I then swapped out the other 2 straight fittings for the 90° fittings and those went on smoothly as well.

Here’s an underside “defensive crab” shot . . .

And the “running crab” shot!

I then set my sights on getting the front fuel sump “Leading Edge” 3/8″ Nylaflow tubing installed.  This tubing will serve as a hidden electrical conduit to get the left GIB armrest comm wires over to the right side and up to the intercom, and also the left side Atkinson fuel site gauge LED wires over to the small wire bundle on the right side as well.

I started off by taping the 3/8″ Nylaflow tubing in place, then gluing it place with multiple dabs of 5-min glue.

After the 5 min glue cured, I then whipped up some micro and micro’d the gaps on the top and bottom side of the Nylaflow conduit.

I then laid up 1 ply of BID over the fuel sump “LE” 3/8″ Nylaflow electrical wire conduit.

Jumping ahead a few hours later, I then pulled the peel ply and cleaned up the layup.  I think I will need to follow up with about 3 x 6″ layups (left, middle, right) to finish off this task.

I also cut up some urethane foam blocks and shaped them into a hexagonal pyramid shape with a flat top for the sump’s low fuel sensor covers.  I was going to do something more fun, like some big hex bolt looking covers, but I realized that if it had a flat surface on it than the GIB might mistake it for the sump top when climbing in and put all their weight on it . . . not good!  Thus, I needed the covers to slant so while climbing in, any passenger who tried to use it as a step point would quickly realize it’s not as their foot slid off of it. Better the GIB have a bit of a surprise stepping-in wise than snap off one of those sump low fuel level sensors . . . especially with a worst-case scenario of causing a fuel leak into the cockpit!

Once I got the foam shape down (again, not perfect . . . oh, well — let’s stuff them where they work fine but no one can see them!) I taped the foam forms to the work table.  I only used a round of duct tape on these forms, so no clear packing tape.  I then laid up 2 plies of BID over each form and left them alone to cure.

After cure, I popped them off –nice & EZ with these types of forms– and gave them a quick trim (below).

I then took my original outline that I made up a few hours ago, added a 1/4″ to the perimeter and then marked up the sump low fuel sensor covers for trimming.  It’s way too late to trim tonight with the noise, so I’ll trim and sand them tomorrow.

Tomorrow I’ll continue on working on finalizing the fuel sump associated components, with an actual & very probable soldering of the sump low fuel sensor wires.  Again, I’ll also continue to work getting all the GIB area stuff squared away.

 

 

Chapter 16/22 – The Cobra strikes!

I started off today by pulling off the right GIB armrest to reveal a nicely floxed in place forward mounting tab.  It is however, a bit too close for comfort to the control tube bearing’s bottom mounting bolt, so some judicious grinding away of some flox and maybe just a hair of the bracket on the outboard side will be in order.

As for the oil heat system, I have a couple things to note before I start on the discussion of my latest build tasks.  First off, since the oil heat mod is of course not discussed in the Long-EZ plans, there’s not exactly an obvious place to put it categorically.  I may break it out later in say a Chapter 27 – Environmental Controls or something, but for now, since the oil pump (and the now superseded fan) is electrical, I have it on a subpage in Chapter 22 – Electrical.  Clearly much –if not the majority– of the oil heat system is not electrical, but that is where it resides topic-wise for now.

Secondly, just a point to say I’m still having camera issues since I thought I had a few more good pics of this process, but they turned out to be crap.  So, we’ll move on with those decent pics I do have…

I cleaned out the foam form innards from the ram air intake expansion chamber top and 90° transition 1-1/2″ diameter port.  The port will traverse through the sidewall into the main cabin just below the left longeron & just aft of the pilot’s seat back.  For the 1.5″ diameter port, I looked all around for something that would make a good form, and eventually ended up using an Ibuprofen bottle since it was exactly 1.5″ in diameter.  After taping it in place I could tell it was going to work perfectly!

After removing the foam, I spent a good 30 min. sanding the inside of the top transition chamber to smooth it out.

Again, here’s a shot of the 1.5″ ID opening.  After leaving the expansion tube, all the ductwork will be constructed with the same cross-section capacity as 1.5″ SCAT hose.

I then prepped two 1″ wide x 10″ long 1-ply BID prepreg setups to glass the top transition piece onto the inlet/transition chamber body.  I mixed up some MGS epoxy with fast hardener and then applied a thin film of fresh epoxy around the ends of each piece that would get glass.

I then wet out the prepregged BID and laid up the first ply with the seam on the outside of the two joined pieces (opposite the 1.5″ opening).  I then laid up the second ply opposite of that with the seam right under the 1.5″ round opening.

I then cut a 1″ peel ply tape down the middle and peel plied just the edges of the newly laid up BID.  After about 30 min of curing, I then set the glassed assembly in the top of an open jug and put it in front of a heat lamp for about 30 min each side.  I had to take the shot below since I couldn’t help but notice how much it looked like a Cobra ready to strike (which I have been face-to-face with, but alas, that is another story!).  With fast hardener that did it for a workable cure cycle.

I then pulled the peel ply and cleaned up the edges of the glass.  Here’s the new single-piece ram air inlet, expansion chamber and transition port ready for install.

I did have getting the wires soldered up for my sump low fuel level warning sensors as a goal to complete this evening, but I simply ran out of time.  I will continue to work the final sump tasks, the oil heat/air system and the GIB area taskers during this next week.

 

 

Chapter 21 – Sump tank complete!

This morning I started out by spending about an hour pulling all the peel ply and cleaning up the layups on last night’s floxed & glassed sump top.  After I got the peel ply pulled and the peel ply edge residue removed, I then put the weights back in place and put the whole thing under heat lamps.

I then went upstairs and with my first cup of coffee of the day starting finalizing the design & circuitry for my GIB map & floor lights.

After getting that knocked out –which I’m very pleased with by the way– I went back down to the shop and started designing the ram air inlet expansion chamber top and transition for getting the air through the fuselage sidewall and into the heating and fresh air ductwork.  The lines you see at the bottom of my drawn top piece are successive height-shortening lines to get the top as low-profile as possible so this thing will fit correctly inside the left baggage compartment mounted to the existing fuselage wall (when the airplane is finished it will be on the inboard baggage compartment wall).

I then cut out a test piece out of urethane and quickly covered it with duct tape, mainly to strengthen it since it was bit fragile in spots.  I set it aside for a while to let the design germinate a bit in my brain while I moved on with other stuff.

I also went out for a bit and by the time I got back it had been 4 hours, which is the minimum amount of time I wanted to post cure the sump top attach layups to the sump base.  By the time I gradually reduced the heat and actually got all the heat lamps turned off, the post cure was right at about 5 hours.

I then configured the front mounting tab for the GIB right armrest.  I determined where it would go, drilled the armrest through the flox hardpoint I made the other day and then riveted a K1000-3 nutplate to the mounting bracket.  I taped up the edge of the armrest before attaching the mounting bracket to the armrest.  I also taped up the top edge of the right GIB storage pocket as well.

I then whipped up some flox using fast MGS hardener and bolted the armrest in place so that the front mounting bracket would be positioned properly as it cured.

I then whipped up some micro and micro’d the edge of the storage pocket.  The goal here is to fill in the gaps between the storage pocket top perimeter edge and the inside edge of the armrest.  When I remove the armrest, the micro will have adhered itself to the armrest, especially since the storage pocket edge has tape on it.

Although I wasn’t planning on doing this next task yet, since I had a decent bit of leftover flox & micro, I whipped it all together and slathered up the fuel lines transitioning the pilot seat bulkhead.  After working the flocro behind and in-between the fuel lines, I then quickly made up a prepreg setup with a ply of BID, which I cut in half and essentially made a narrow crossed “X” with the BID tapes over the flocro’d up fuel lines.  It’s not the prettiest thing but it looks like it will be nice and strong and I’ll clean it up a bit after it cures.

I then set my sights back on the fuel sump.  I started off by cutting out 2 gaskets out of my cork-rubber gasket stock for the two sump access holes.

I then drilled counter sinks into the 7 holes on each cover plate and then installed the cover plates for the time being to keep dust, dirt and anything else out of the sump tanks. I took the shot below after I had just finished mounting the left sump tank access cover, but while the countersinks on the right sump tank are still visible with no screws.

Tomorrow will be a lighter build day, but I do plan on continuing to finalize the install of nearly everything in the GIB area, including finishing up the install of oil heat and fresh air venting system.

 

Chapter 21 – Sump tank top mounted

I actually took these pics yesterday, but I’m merely rolling them into today’s post.  Here is the ram air inlet & expansion chamber after the glass cured and I ripped the internal urethane foam plug to shreds to get it out.

Here’s the other side, although the angle makes the 1″ diameter opening look much wider than it is in comparison to the rest of the air inlet.

Today I cleaned up the layups of the 2 Holley Hydramat screw posts that I floxed and glassed into the right front corner of each sump tank.  Below is the right sump screw post and fuel drain valve shown in place with the Holley Hydramat installed.

I then sanded virtually every surface on the sump, shop vacuumed it all and cleaned it up. I then prepped for the final mounting of the sump top by taping all the openings that I didn’t want any errant flox or epoxy getting into.

I then removed the access cover tops and sanded both sides of the sump top, in whatever surfaces were subject to getting glassed to the lower sump base.  I did have to Dremel around the forward floxed edge of each access hole nutplate ring to ensure that it was smooth, yet a bit textured for yet another round of flox.

I then spent 6+ hours total floxing and glassing the sump top to the sump base. Why did it take so long?  Well, one reason was I underestimated –a couple of times– just how much flox was required on all the parts of the base to get this sucker glassed in place!

After I finished cleaning up at the end of this unannounced monster layup, I took a shower and went out to grab a celebratory beer & burger.  When I returned an hour or so later, while checking the layup, I went ahead and removed all the tape that was around each hole protecting the nutplates from errant epoxy, flox, etc.  I also trimmed back the BID and peel ply about 1/8″ further towards the front sump wall away from the front edge of each hole to provide a nice ridge-free setting for each access hole cover plate and gasket.

I also cleaned up something I forgot to mention earlier, and that was the mounting of the second foam fuel line mounting bracket.  I had mounted this earlier, then floxed up the fuel lines and threw on a quick piece of 1″ wide BID from about an inch above the bracket, all around the front over the fuel lines, to about an inch below the bracket.  I used MGS with fast hardener so after about 8 hours it was definitely ready to be trimmed and cleaned up.

It won’t win any beauty queen awards, but it looks and feels nice and sturdy.  Besides, all the fuel lines, foam brackets, big yellow power cables, etc. will be stuffed away behind an upcoming 1/16″ Balsa wood and BID kick plate that will sit just in front of the fuel lines [in line with the outboard side of the flight control tubes… the kick plate cover will not be an extension of the GIB armrests].

Tomorrow I’ll take some steps to finalize the install of the sump top to the sump base.

Chapter 21/22 – GIB area stuff

As the sump access ports’ floxed nutplate rings are still curing on the sump top, I figured it was time to get some other tasks completed in and around the GIB area.  I started off in the sump itself by drilling a 1/4″ hole into the bed of micro in the left sump tank to mount a “roll-it-yourself” 4-40 countersunk stainless steel screw as a clickbond.  This 4-40 screw post doesn’t have to be super strong and in many ways will serve as a guide to ensure proper Holley Hydramat positioning in the sump tank… if there actually is such a thing! I say this because with the hard mounted tubing, I don’t see the Hydramat straying off anywhere other than where it is supposed to be.  But again, a 4-40 screw post will serve as a nice guide during the initial install and subsequent replacement of the Hydramats.

I then set the 4-40 countersunk stainless steel screw in place.  It looked like a nice fit!

On the right side I couldn’t place the screw post (aka “clickbond”) near the center sump wall since the fuel line tubing going to the left sump is right over where it would need to go. I thought a few minutes about not putting in a screw post on the right side, but then figured if I put it near the drain valve, I doubt seriously if it’s going to block any water draining into that area.

However, since I wasn’t drilling down into the micro-contoured floor, the drain corner didn’t provide the depth I had counted on for the 3/4″ long screw. Standing on the bottom tank floor alone, it was just too tall.  I punted and used a regular 1/2″ 4-40 stainless steel screw, but covered it with an upside down Tinnerman washer to help stabilize it once it was awash with wet flox and subsequently cured –along with a couple plies of BID over top of it.

To get the normal screw to stand upright in space I simple taped it to a line, then clamped the line to a popsicle stick hanging off the top of the longeron like a diving board.  I then 5-min glue the bottom of the screw, slightly adjusted the line where I wanted the screw and Voila! … the screw ended up exactly where I wanted it!

I then floxed in the 2 Holley Hydramat 4-40 corner screw posts, covered each one with some wet BID, and then peel plied them.

When I 5-min glued the 4-40 Hydramat screw post in the right sump tank, I also 5-min glued the remaining center area –top & bottom– of the piece of German “PVC” pipe that I’m using as my antenna channel cover.

After the 5-min glue cured, I then got to work mixing up some thick micro, slathered it on each side of the channel cover, and then laid up 1 ply of BID over top of that. Of course I peel plied it after I was done with the layup.

I then decided to take on one of the more challenging tasks on my list: the ram air inlet and expansion chamber for the oil heat system and fresh air intake.  This ram air inlet will also serve to pressurize the cabin more to help offset the negative characteristic of Long-EZs to suck all the bad stuff (cold, rain, small reptiles, etc.) from the outside . . . as per Nick Ugolini who has compelling evidence that his findings work!

I made a bad assumption in thinking that the urethane foam I have on hand was 2.5″ thick, when in fact it is only 2″ thick.  I had already confirmed with Nick that instead of a 3″ round diameter expansion chamber, that I would be making mine more oblong, or oval, shaped to save some room in the RHS baggage area.  I had planned on making it 3.6″ high x 2.4″ wide.  Well, I ended making the expansion chamber just a hair longer since that was the only dimension I could control with this foam, to still come up with approximately the same volume as I would have before.

I then shaped the curved inlet and expansion chamber out of the urethane foam.

After finalizing its shape, I then covered it with duct tape first, then with clear packing tape.

Here’s a general look at how it stacks up with my planned shape.

As you can see, the cross section turned out to be a bit more square than I had originally planned (Hmmm, I wonder if Burt ever had this thought cross his mind about the fuselage he designed . . . ha!).  Again, to make up for some of the 0.4″ in width that I lost due to the urethane foam block width.

I then very quickly mocked it up on the sidewall to see how it looked.

I then also quickly made up a glassing spit for the ram air inlet & expansion chamber.

Here’s a better shot of the glassing spit.  If you’re thinking that I got really fancy with my upright (I know you’re not!), it might look familiar: it’s one of the sump test ribs that I cut out of OSB plywood.

I have to admit I failed in my layup goal here.  Except for a reinforcement ply of BID at the front and the back for interface strength with other upcoming duct pieces, I was going to use spare UNI for the entire layup since I have a ton of it laying around.

Ugh!

I couldn’t do it…. what a royal pain that stuff is trying to go around any smallish curves.  I did got a couple of plies on, but the small front 1″ opening was going all wonky on me and after fighting off the attack of the killer strings for over half an hour, I finally threw up my hands and magically one of them landed on a piece of BID . . . A SIGN!  ha!

Ah, laying up a ply of BID after fighting UNI is like eating real butter!  Smooth & silky! Anyway, I added a final ply of BID, peel plied the ends and the seam down the side and called it a night.

Mission complete.  Tomorrow I won’t get much done.  Out of town visitor flying through to fly out, then a birthday party after that . . . busy, busy!  I will continue to work on both the sump and the GIB area stuff for a few days before heading north, or forward, to the pilot’s seat area.

 

 

Chapter 21 – Fuel sump top GLASSED!

For clarification, the glassing of the fuel sump top is final, but I have yet to flox/glass it in place on the sump tanks assembly . . .

So, as I mentioned last night, I let this layup cure to around 80% and then placed it on the sump assembly in the fuselage, where I then weighed down the edges (again) and cooked it to perfection with heat lamps!  Before I actually put it back onto the sump assembly though, I did pull the peel ply (while it was EZ!) and knife trimmed all the edges.  I also removed the peel ply intersection ridges and drilled out the 7 screw holes on each access hole perimeter flange.

The usual temp that the backseat area gets to in this configuration is around 120° F, so I figured I would let this cook for about 4 hours.  I went upstairs and spent a good hour migrating my blog posts over into the build log pages, and then went for a quest for some 8-32 screws –which I bought at my local village hardware store– and some cork-rubber gasket material, which I picked up at a local auto parts store.

I chose cork-rubber gasket material since the sump access port perimeter surfaces that I’ll be using the gasket on is not perfectly even nor totally smooth.  Cork is the most forgiving of the affordable gasket materials, and from all accounts, once married up with the venerable Permatex #2, it’s virtually leak proof.

Upon returning home I got everything prepped and ready to start back in on the sump build, while the sump top itself had post-cured for right at 5 hours.  Again, I had pulled all the peel ply and knife trimmed it before I cooked it, so this time around I was just checking the layup over for quality (there were some minor delams where I folded the glass around the edges of the foam which I simply cut away) and giving the edges a nice final sanding with the hardboard [FYI/FYA – Pulling peel ply after a part has been post cured is NOT fun!].

One of my first tasks out of the gate today was I needed to trim down the outside edges of each sump access hole nutplate ring.  Since the glass on the bottom side around each hole went just a tad wonky on me, I needed to make the footprint for each nutplate ring as narrow as possible.  I trimmed up each ring with the Dremel tool and a cutoff disk, and then finished the edges with a couple rounds of filing.

I then started an iterative process of trimming away half circles on the front sump wall flange to allow clearance for the nutplate rings once mounted in place on the underside of the sump top.

I was also a bit concerned with the sheer wonkiness of the right access hole glass, so I checked it out first with the top cover plate in place to ensure it didn’t need any special attention. Actually, the only special attention I had to give anything was that I had to curve the top cover plates a bit for a better mounting contour.  Now, even though these cover plates are ONLY 1/16″ 2024 aluminum, they are NOT EZ to bend!

Well, I got the top plates bent well enough, and then test mounted them both into place with a full compliment of 8-32 screws into their respective nutplate rings on the opposite/interior side of the sump top.

After a half dozen rounds of trimming the sump front wall mounting flange, I was able to slide the sump top into its final mounting position with clearance for both access holes’ internal nutplate rings.

With the sump top ready to be mounted, I decided I wanted to try it out to ensure there just wasn’t any unforeseen problems I was missing.  Plus, I was curious how well it would work.  The picture below may seem like some crazy guy taking a really weird pic, but I wanted to show that both GIB left & right armrests were installed, plus the sump top was in place.  This is the first time that I’ve sat in my plane when it actually felt like a real seat in it!

How does the thigh support feel?  AWESOME!  I haven’t sat in too many Long-EZs, but whether or not any builder is using a thigh support sump, they should definitely go for the thigh support.  It felt so good I almost fell asleep just sitting there pondering my build!

The next step was to get the access holes’ nutplate rings floxed to the hole flanges on the internal side of the sump top.  I whipped up some flox using E-Z Poxy and very carefully floxed the nutplate rings in place.  I had planned on using the access hole cover plates to help ensure the angle of the screws were correct, but right about when I was getting ready to put the screws into the flange on the left side, I heard a huge crash upstairs.  Something had definitely fallen.  Well, my fingers were all covered with flox so I quickly put the screws in and tightened down the nutplate ring, removing all the excess flox that was oozing out as I tightened the screws.

Before I did the right side, I went upstairs to investigate the potential calamity . . . well, apparently Jack Wilhelmson’s canopy latch kit didn’t like my tall surround sound speaker and took it out.  I uprighted the speaker and separated the two, and then got back down stairs to finish floxing on the right access cover nutplate ring.  It was then that I noticed in the distraction of the loud bang of something falling down upstairs, that I had forgotten to place the access hole cover in place on the left side.  Oh well, I’ll mount it when I do the screw swap outs to ensure the screws don’t get floxed into place.

I plan on letting the floxed nutplate rings cure for 2, if not 3 days, to ensure the flox really holds these guys in place.

Since I knew I would mixing up flox, before I started the process of floxing on the access holes’ nutplate rings I marked & dug out the foam on the front edge of the GIB right armrest to create a mounting tab hardpoint.  Thus, after floxing the nutplate rings into place, I added some micro to the leftover flox for a good mix of flocro and then filled in the hardpoint divot on the GIB right armrest.  When I get a chance over the next few days, I’ll flox the GIB right armrest mounting tab into place onto the aft side of CS118 mini bulkhead.

Tomorrow I’ll be working on other tasks besides the fuel sump as I let the floxed nutplate rings cure fully.  I do need to prep the internal floor of each sump tank with a 4-40 click bond (most likely a roll-yourself one) to ensure the Holley Hydramat stays in place on each side.  I also need to clean out the fuel lines before the sump top gets glassed into place.

 

Chapter 21 – Sump top glassed

I started out today by spending over 6 hours updating various parts of this website.  I cleaned up the electrical system main page by adding subpages, and I added a subpage to the Chapter 21 page for the GIB thigh support fuel sumps.

I then finally made it into the shop very late in the afternoon to start in on the fuel sump top exterior.  My goal was to get the sump top exterior glassed today, which I was able to do.

I started by spending a couple of hours working on the sump tanks access ports’ holes. My theory on the glass pulling away from the foam was right for the most part, which distorted the shape I had created for the way the metal nutplate rings would lay in the depression ring around the underside of each hole.  Being an ‘ol Bomb Disposal Tech, I simply improvised, adapted and overcame by taking the topside hole perimeters down to glass.  The glass ring around each hole isn’t optimum for what I want to do, but it’s definitely workable. Most notably, what it will probably mean is that each top cover plate will have to be curved slightly to match the (now) more curved shape of the just glassed rings.

Once I removed the foam around each access hole and took the hole perimeter down to glass, I then found the optimum alignment between top and bottom plates, then drilled the 7 screw mounting holes in the ring around each access hole.

I then sanded a transition in the foam around each hole to the surrounding foam surface, and also hit the raised “square” edge lines that where an unwanted byproduct of curving the foam with heat and using a weighted board to make the curve.  I should note that I had already sanded both the right and left sides of the top to get the edges aligned with their respective sump walls, exterior/outboard sides. Once I cleaned up the top foam surface of the sump top, I then vacuumed it in prep for glass.

As for the glass schedule for the exterior of the fuel sump top, it was slightly different than how the rest of the sump was glassed.

Obviously I want this sump to be more impact resistant than if I had just used BID alone. So, for both strength and impact resistance, and to add another ply for fuel resistance, I made the first ply on the interior sump walls Kevlar.  However, since the top will see its fair share of things dropped on it, getting stepped on, pointy things trying to pierce it, etc. I went ahead and put the Kevlar on the exterior side, covered by a ply of BID.  I did add another 6″ wide strip of BID across the front of the top cover for strength, especially for the glass-to-glass access holes’ rings.  Then, immediately around each sump tank access hole, I added another ply of BID.

Finally, before I laid up the final top ply of BID, I added a small strip of Kevlar in the center in between the access holes (where the bridge of the “nose” is on my very humanoid looking layup . . . can you see the eyes?!) which is essentially where the GIB will step every time when ingressing & egressing the airplane.

I’ll let this layup cure to around 75-80% (i.e. in the morning) before placing it on the sump assembly in the fuselage, where it will get weighed down on the edges (again) and cooked to perfection with heat lamps!

 

Chapter 21 – Interior layup cleanup

Today I started off by shutting off & pulling the heat lamps from the sump top interior layup post cure.  I then slowly and carefully pulled all the weights off the top.  I then carefully worked the top off of the lower sump walls and flipped it over to inspect it.  All the glass was in good shape.

The only minor issue I had –unintended consequences– was that the BID that was securely in place in the “pockets” around each access hole separated off the foam surface slightly in a few areas.  I’m thinking that in the depressions for each access hole, they probably pulled out just a hair in those few areas because I pulled the glass slightly taunt around the holes by weighing down the entire sump top foam plate with weights.  No major worries.  A bit more work and assessment, but still very workable.

I then proceeded the quite understated process of pulling peel ply, cleaning up the peel ply edges and trimming the glass overhanging the perimeter edges with the Fein saw.  This entire endeavor took nearly an hour by itself!  I left the glass in the access holes so that when I’m sanding and shaping the topside hole perimeters, the glass will serve as a “catch” to keep all the foam bits & dust from getting into the sump tanks.

After cleaning up the layup and trimming the overhanging edge glass, I then stuck the sump top back in place.  I’m very pleased with the fit and all indications convey that it mates securely at every contact point along the top of each sump wall.

There is a slight unevenness to the top since the weight on the right side pushed the aft side of the right access hole down just a bit more than the left, maybe 1/8″.  But with a bit of judicious sanding and when the top ply of Kevlar and BID are glassed into place, I think it will be barely noticeable, if at all.  It certainly doesn’t have an operational impact on the sump.

Tomorrow I’ll continue my quest to get the sump top glassed into place, with the access ports’ nutplate rings floxed into place and the screw holes drilled out.