I started off today making a paper template that will allow me to fill in the oval cutout of the firewall with 1 ply of Kevlar to add a bit physical and heat protection –as well as some noise dampening properties– to the bare shear web.  To be clear, the CS Spar will be bare during the build then covered with Fiberfrax and 6061 firewall covering (yes, regarding using aluminum as the firewall covering I’ll reiterate that I ascribe to Burt’s design that uses the aluminum as the structural covering for the firewall that also serves to protect the Fiberfrax… which is the REAL fire barrier in this configuration).

I then used my oval firewall template to mark and cut out the ply of Kevlar.

I prepregged the Kevlar ply then laid it up on the bare CS Spar shear web, peeking out of the oval cutout in the firewall.  I used fast hardener so that it would cure as quickly as possible.

I then peel plied the Kevlar ply layup and let it cure well into its green state.

With the Kevlar layup still slightly tacky but cured enough to let me carefully pull of the peel ply, I then created a fairly dry flocro fillet (about 70% micro/30% flox) around the edge to transition the 1/4″ plywood edge down to the surface of the CS Spar for a good glass flow.  I then laid up my prepregged 1-py 1.5″ wide BID tapes around the perimeter, covering the flocro fillet and overlapping onto both firewall face and the ply of Kevlar I had just laid up. [Note that in this pic and a couple below you can see where I flocro-filled the gaps in the “L”-shaped firewall openings around each engine mount extrusion].

Here’s a full firewall view shot of these layups.

To both prep the surface for better adhesion to the 3M high temp RTV that will secure the Fiberfrax in place to the firewall, and to remove the nasty, jagged sharks teeth of death that await unsuspecting fingers and forearms, I peel plied the perimeter BID layups.

A few hours later I pulled the peel and was somewhat pleased with the results.  I say “somewhat” because the actual layups are fine, but I think I allowed myself to fall a little prey to groupthink here in that I have seen this style firewall layup done on a number of Long-EZs.  However, with hindsight being 20/20, if I could go back and do it again, I think I would simple bevel the firewall plywood with a router to provide a simple transition from the firewall surface to the CS Spar.  Although I used somewhere between a paste to dry flocro, it still added more weight than I would have preferred, even though I tried to balance weight vs strength.   Oh, well. It’s done and I’ll press on!

I then set my focus on installing a Clickbond on the right inside edge of the oval opening of the CS Spar to be used as an Adel clamp hardpoint.  The Adel clamp will secure the wires transiting from above the CS Spar to the Hell Hole, keeping them both secure and out of the way of the opening to allow for placing stuff into the spar and removing it without getting hung up on loose wires.

As per normal, after I sanded the surface and 5-min glued the Clickbond in place, I then laid up 2-plies of BID over the Clickbond and peel plied it.

My final official build task of the evening was to finalize the install of the right side flight controls to the mini-bulkheads in the front and GIB side consoles (CS109 & CS118).  I gathered up all the hardware per plans and then bolted the bearings in place, again to the CS118 mini-bulkhead aft . . .

and to the CS109 mini-bulkhead up front.  I’m using the Cozy Girrrls control system hardware, so their bearing assemblies at each end of the control tubes may be less thick than stock, because the AN3-7A bolts called out for in the plans are a bit too long in my book.  But again, they work and the control system is installed, so a short thought to ponder.

I have a few more minor tasks to complete tomorrow and then I will be moving into –either tomorrow or Monday– what I’m going to call the “3-DAY BLITZ” (….key dramatic music!), whereupon I will be solely focused on FINISHING UP THE WHEEL PANTS INSTALL.  Yes, I just said THAT!  . . .  In short, I want to get some of these half-finished mini-projects off the list of things to do and on the finished column.

Only 7 years to get it done . . . not too bad!  Haha!

I started off finalizing the install of the remaining Hell Hole components before installing the firewall.

The first order of business was shaping the last bit of 3/8″ aluminum tubing for this airplane to finish up the fuel lines from tanks to firewall.  I had to shape and terminate 2 lengths of tubing with AN -6 fittings on each end.

I started on the backwards question mark looking piece that is the final run of tubing before getting attached to the firewall pass-thru fitting.  I try to avoid right angles on my fuel lines (not that it would matter that much here, honestly… I just didn’t have any fittings on hand) so I made this swooping loop with shallow right angle curves.  With this done, it would determine the length of tubing required for my cross connect between the FT-60 Red Cube fuel flow meter and the 30 micron filter (required by Silver Hawk fuel injection system).

The tube cutting, bending and flaring process went without event, and I must be getting decent at this stuff because these two lines are the only ones I made: as in no extra pieces of mangled tubing scattered on the floor . . . not that I haven’t done that before!

In the first piece below, you can see a black dot on the wood cross piece I clamped in place to simulate the inside surface of the firewall.  This dot was my target end point for the tubing and for placing the fuel line firewall pass-thru fitting.  I was fairly close on my final configuration.  BTW, as you probably surmised, the wood cross piece is to simulate the firewall not only for guesstimating the fuel line exit point, but also to ascertain the depth required to give me the proper tube length between FT-60 and filter so that the fuel filter Adel clamp would be positioned up against the forward side of the firewall for mounting.

With the fuel line and filter in place, I then verified that the SD-8 relay and fuel filter could coexist in the same area . . . which they can quite comfortably.

Speaking of the SD-8 B/U Alternator relay, as you can see I permanently mounted it in place under the CS Spar.  After I took this pic (and video) I then taped it up to protect it from any errant epoxy when I mounted the firewall in place with BID tapes just aft of the relay.

Since it was a quick kill, I terminated the big yellow ground cable with a ring terminal for eventual connection to the big brass bolt that goes through the firewall…. with the engine ground strap attached on the hot side of the firewall and the forest of tabs on the cold side.  [I can’t do this with the starter power lead since it will need to get run through the small stainless steel firewall fitting first before it gets terminated].

I slipped on an appropriate label and hit it with the heat gun, then a short length of black heat shrink to cover the crimp.  Then I clamped this baby up tight in the vice!

I then finished off the crimp with some heat shrink.

And Voila!  The final terminated big yellow ground cable that gets bolted to the forest of tabs post inside the Hell Hole.

Then, to cover all my recent lower engine mount extrusions, engine mount, Hell Hole wiring and components installs, I made up a short (kinda) video to provide an overview of what I’ve been up to.

I then snapped a couple final official shots of my bird sans permanently mounted firewall….

The pics above were actually taken after my initial task of cutting and micro’ing into place a small piece of foam filler on the lower aft end of the left fuselage sidewall.  Again, since my fuselage is much more football shaped than a stock Long-EZ, it really places each end sidewall mating surface –that would normally mount near-perpendicular to the front face of the firewall– at a more significantly oblique angle to the firewall face.  To account for these odd mounting angles, it requires some more judicious filling with foam, flox, and micro.

It took me yet still another hour+ to get the prep finished before I started mixing my first batch of epoxy.  I then set about mixing a boatload of flox to get all the interfacing surfaces covered before clamping the firewall into place.

It took a bit, but once I got the firewall set in position I then laid up my prepregged 2-ply 2″ wide BID tapes (boy, it’s been a while since I dealt with BID tapes!), starting on the top CS Spar to firewall junction across the spar in-between the top engine extrusions.  I peel plied this layup since I would be in the D-Deck/GIB headrest compartment a fair bit and decided to forgo having my hands ripped to shreds with wonderful invisible glass spikes.

I then laid up the 2-ply 2″ prepregged BID tapes on the bottom side CS Spar to firewall corner, and both the left and right corners.  As you can see, before I did any of the BID tape layups I added a flox fillet to each corner.

A bit wider angle shot of the lower CS Spar edge 2-ply BID tape to the front side firewall.

Here are the corner BID tapes.  After I reviewed these pics I went back in and cleared out a couple of those air bubbles.

I then spent well over an hour tweaking and cleaning up the flox gunk from all over the firewall.  All in all, a step that I thought would take 2-3 hours at most [I mean, com’n, we’re talking 4 BID tapes here… ] ended up taking about 6 hours!

As you can see, I used a cargo strap to pull the lower firewall in towards the fuselage to align the firewall top to bottom.  In actuality, the bottom is pulled closer to the fuselage by about 0.050″ to 0.060″ (<1/16″) to compress it tighter with the lower aft fuselage sides. This action squeezed out a decent amount more of flox so helped minimize weight just a tad more.  Plus, once all the lower cowling attach joggles are glassed in, it will be near impossible to tell that the lower firewall is set/angled forward less than 1/16″ of an inch more than the upper firewall.

And here she is: the attached firewall! Woo-hoo!

Tomorrow I’ll sand, flocro and glass the edges of the oval with 1.5″ 1 ply BID tapes to both secure the firewall more to the face of the spar and to help seal it up.

I started off today finishing up the wing lights wiring harness #2 for the wings’ landing, taxi and Wig-Wag lights that will be mounted on the leading edge of the wing anywhere between the end of the wing and the outboard 1/3 of the wing…. with the goal to get them as outboard as possible.

This wiring harness actually involves a 20 AWG 2-wire shielded cable and then 2 external wire runs as well.  On the shielded cable, I started by separating the internal wires and tying all the white wires, white/blue wires and the shield from the 3 separate cables: Left wing, Right wing and panel switch/power.

I then soldered spliced the bundled wires.

With the cables in a “T” configuration, it made it a bit challenging to heat shrink it all. So I did what I could on each leg, then used flight line tape around the center axis and secured that with some wire lace.  Yes, Dr. Frankenstein would be proud, but it is secure!

Here’s the end result for the wings landing, taxi and Wig-Wag lights harness.  Along the top is a blue (L) and green (R) wig-wag sync control cable, then the shielded 2-wire cable that provides separate power feeds for the taxi/landing light and the Wig-Wag functions. On the lower side you can see a black wire which is of course the ground wire.  It shares a ground terminal with the shield ground lead from the 2-wire shielded cable.

I should point out that I had a good in-depth conversation today with AeroLEDs confirming my wiring scheme for all my wing lights, and they confirmed that I was installing them in the best configuration for a Long-EZ.

You may also note from the pic below that I spent a bit of time printing out wire labels and affixing them to the wires, both on this harness and on the Nav/Strobe lights harness I made last night.

I then grabbed my wiring harnesses and a handful of unattached wiring labels and headed to the shop.  I ran the wing wires up through the holes from the hell hole side.

Once the wires were through the holes, I then attached labels for the wires running inside the CS Spar.

If you look closely, you can make out the wire channel that I drilled through the angled part of the front lower corner of the CS Spar.

Here’s a Hell Hole shot of the wing lights wiring harnesses from below.

And a taller shot of the wing lights wiring harnesses.  The coiled up wires in the lower right of the pic will head forward to the respective light switches on the panel.

Admittedly, I have a fair bit of slack for the wires exiting out the ends of the CS Spar, especially on the right side.  But better to have a little excess than not enough, eh?

With the wing wiring harnesses in place in the hell hole/CS Spar, then came the questions regarding routing and securing.  I wanted to ensure the wires were routed in an optimized fashion, to include accounting for the aileron control tube that transits through the Hell Hole.

After assessing and fiddling about with possible wire runs and securing options for a good 20 minutes, I finally decided on securing the wing light wiring harness “T” junctions with an Adel clamp set up high on the aft side of the GIB seat back bulkhead, well over to the right side.  Although I had originally planned on keeping the “noisy” wing light wires as far from the “normal” wires as possible, I have accepted why this area has the moniker “the Hell Hole” as there is just not enough space to keep them all separated.  What this means in practical terms is that the upper Adel clamp will secure pretty much all the wires entering/exiting the Hell Hole from the sides and above: both the special “noisy” wires and the “normal” wires.

I also added 2 plastic wire tiedown points in the middle and left on the upper seat back. If they look a bit low and askew, well… they are!  When I installed them the wire bundle was higher up (read: in the way) and I placed a dab of 5-min glue in the center of each one.  Well, as I was installing each one, the angle of the seat got the best of me and the original sticky backed pad on each tiedown point caught the seat just enough to pivot the tiedown forward and set it on permanently where it hit.  Yes, this got me on both of the tiedown points… so they sit where they caught the seat! If I screw up, I like to do it twice to confirm that I screwed it up right!! (ha!)  Luckily, they aren’t too low and will work fine.  Thank goodness they’re in the Hell Hole… don’t tell anybody how crappy they look!

Besides the Clickbond that I bonded/glassed in place high on the seat back for a wire-routing/securing Adel clamp, I also added another RivNut hardpoint a few inches below and outboard (next to the seat access hole) for the same reason.  You can see I floxed it in and taped it into place with gray duct tape.

I actually added a third hardpoint with yet another RivNut going straight down in the GIB seat back opening (it’s covered in black electrical tape).  This Adel will essentially be the Gatekeeper for all the smaller wiring transiting into and out of the Hell Hole from the forward fuselage.  With this setup what I’ve done is stay inline with Bob Nuckoll’s advice of keeping the big power wires separated from the little wires since this Adel sits a good 4-5″ above the big power wires coming from the battery compartment.  Of course I will do all I can to maintain this separation the entire length of the fuselage.

I then got to work on the SD-8 B/U Alternator relay.  My goal was to make the last connection point on the SD-8 a separate removable one for terminating the SD-8 voltage regulator power wire that comes in from the D-Deck/turtleback.  My initial solution was to merely add knife splices to lengths of wires coming from both the voltage regulator and this relay, when an even simpler solution hit me: a double-tabbed PIDG FastON terminal. That would allow me to simply terminate the incoming voltage regulator wire to the relay with a standard FastOn terminal.

All this is taking place at the furthest right corner of the relay in the pic below, where the bare FastOn tab is visible on the edge of the relay.  Again, this is where the power wire from the SD-8’s D-Deck located voltage regulator will get connected to the relay.

I then prepped the relay wire bundle by securing the Over Voltage module and wire lacing the initial wire runs coming from the relay.

Here’s a closer look at the wire lacing on the SD-8 B/U alternator relay wiring harness.

Tomorrow I’ll label the SD-8 b/u alternator relay wires and continue with my in Hell Hole tasks in prep for installing the firewall.

I feel like I have a cat now because I started off the day skimming the top layer of pink desiccant out of the engine dehydrator container (just like the proverbial kitty litter box).  I also pulled initially 2, then 3, engine dehydrator plugs and swapped out their pinkish desiccant for nice deep, rich blue desiccant.

Here’s the third and last engine dehydrator plug in which I swapped the desiccant out.  I placed it on the bed of pink desiccant that I was just getting ready to pop in the oven for an hour or two at 240° F.  Not pictured are a half dozen desiccant bags I pulled out of the engine’s exhaust ports and air intake plenum to also dry out as well.

After the desiccant returned back to its brilliant blue color, I dumped it back into the engine dehumidifier tub and replaced all the desiccant bags.  Before I did all this my engine was at 21% relative humidity internally, and about a half hour after I finished with my desiccant shenanigans it was back down to 12%.

In the movie So I Married an Axe Murderer, Mike Myers has a line where his character states to Nancy Travis that he believes that “all Scottish food is based on a dare.” Well, sometimes I feel that way about building Long-EZs: that all majorly important steps are based on huge dares, fraught with the exacting fear that if you screw it up… well, really bad stuff awaits.  Like major rebuilds or just parting with a lot of money to fix it.

The biggest two build dares that come to mind involve drilling: First, drilling the wing bolts through the CS Spar into the wings has got to be the biggest right of passage on a Long-EZ build… simply crazy.  Second, is drilling the engine mount bolts into what is supposed to be 5/8″ engine mount tubes (I just extrapolated this info from a conversation I had with Dave B!) whereupon mine are actually 9/16″ in diameter… let me tell ya, in this situation that extra 1/16″ might as well be an added meter on the target!

Ok, here’s another odd statement that is probably rarely heard: So I fixed my “loose” bolt hole drilling problem by swapping out my REAMER for just a standard 1/4″ DRILL BIT. Crazy? Yes. True? You betcha!

When I drilled out the vertical bolt hole in the lower right engine mount I used a 1/4″ drill bit for the final 1/4″ hole.  The fit was way better than the 1/4″ reamer since it took a bit of finagling to get the bolt to go into the hole.  Woo-hoo!

I then drilled the horizontal bolt hole in the lower left engine mount to finish off that position.

I again calculated the midpoint of the engine mount tube and the 3/16″ thick engine mount extrusion and drilled from the outboard side in.  It worked a treat!

I then had 5 of the 8 bolt holes drilled . . . nearly 2/3rds of the way finished!

As with an alternating clamping process of attaching something into place that has a lot bolts or screws, my next engine mount tube to be completed with the drilling of the second bolt hole (forward/vertical here) was the top right position. Clearly on this one I was able to drill straight into the engine mount tube itself.

I then jumped back down to the lower right engine mount to drill the forward side horizontal bolt hole.  I started with a 1/8″ starter hole as shown below.

And ended up with a 1/4″ bolt mounting hole.  Again, after the initial go with just using the 1/4″ drill bit, the reamer went back on the shelf…. the 1/4″ drill bit simply did the job in stellar fashion.

Here we have the finished engine mount bolt holes on the right side:

Of course finishing off drilling the lower right engine mount bolt holes meant that both lower engine mount bolt holes were completed.

Yes, not a great pic, but the best I have for viewing the fitted temp bolts on the lower engine mounts.

I then finished the engine mount installation by drilling the vertical bolt hole on the upper left engine mount tube.  Both this bolt hole and the horizontal took significantly longer with quite a bit more effort than any of the others, because remember in this position the engine mount extrusion is 4130 steel (which may help explain why it’s so much narrower than the other engine mount extrusions).

Here’s a shot of the top engine mounts with the bolt holes all drilled.

I then double-checked my slightly modified angle and, again, using a 0.224″ spacer (drill bit) vs the plans 1/4″ (0.25″) spacer, I was at exactly 90° [Note that although the board is in place on the engine mount, I am measuring the angle with my contact points for the level and spacer positioned on the board as if there was no board present].

Bam Baby!  90° on the nose . . . now that’s the money shot!

Here I will regale you with a plethora of officially installed engine mount pics!

Tomorrow I’ll be doing a fair amount of work in the Hell Hole in prep for the installation of the firewall that should be taking place within the next 3-4 days.

Initial engine mount install that is…

I started off today by trimming down and then rough sanding the foam plugs that I have micro’d in place over each outboard end of the lower extrusions’ bolts, nuts, and wide area washers…. for both the right and left sides.

I then removed the engine mount –which is a tight fit– exposing the 4 engine mounting extrusions.

here’s a closer look . . .

Using the taped up SD-8 relay and some 5-min glue, I mounted the 2 SD-8 relay Clickbonds on the underside of the CS Spar towards the right side a bit.

When I was making up my 3×5 card task list this morning, I also decided to verify my desired locations for the right and left brake line runs.  I wanted them below the main gear so they were as accessible as possible via the bottom Hell Hell cover (disguising itself as an intake scoop) once the plane is completed.

I confirmed the positions and sanded down the areas that would get a few plies of BID to secure the Clickbonds into place.  BTW, the Adels that are getting mounted to these Clickbonds won’t directly clamp to the brake lines, but rather will secure each side’s 3/16″ (from the wheel calipers) to 1/8″ (fuselage brake line run) Generant reducer fitting.

As the 5-min glue set, I then prepregged all the BID for laying up over the Clickbonds. Just before mixing up some epoxy with fast hardener, I wrapped each Clickbond threaded post with a small piece of electrical tape to protect against any epoxy gunk.

I then laid up 3 plies of BID over the SD-8 Relay’s Clickbonds and then peel plied it.

And did the same for the right & left side brake line Clickbonds.

I then got to work on drilling the engine mount bolt holes.  I had an entire plan of drilling the engine mount with it off the extrusions, since I was thinking there wouldn’t be enough clearance for a drill to get a straight shot at drilling the bolt holes.  There may not be enough clearance for the bottom horizontal bolt holes, which are forward on the bottom, but for the top horizontal bolts (which are the aft positioned holes) there’s plenty of room.

Also, instead of messing around with some inherent induced error by measuring from F28 or the panel, I went straight to the tip of the extended pitot tube to measure the final position for the top engine mount cups to get them both at F.S. 134.2 AND equidistant from the very front tip of the plane [to be clear, I did FIRST confirm F.S. 134.2 from F28 since I needed a known F.S. to measure off of].  I’m fairly certain I’m off maybe 1/32″ at the most… maybe, maybe just a hair higher if we account for any flex and angle of the measuring tape, but definitely close enough that “these dogs will hunt!”

After drilling a very small pilot hole just enough to guide a larger bit, I switched to a long 1/8″ drill bit for the initial round, then stepped up a couple bit sizes each round.  Of course, going through 4130 took a bit for the initial hole, but went smoothly after that.

Here’s the break through on the right side.

And the left.

I then used a 0.25″ reamer, that actually measures out at about 0.246″ on the calipers. Perfect, I thought, but there was no resistance to the bolts when I slid them into the bolt holes.  Disappointing, but follows in line with what my buddy Dave Berenholtz experienced when he drilled his engine mount holes down in OZ (And here I just thought it was a hemispherical gravitational thing on his part . . . ha!)

Here’s the nicely aligned but not-as-tight-as-it-could-be bolt test fit in the upper right engine mount horizontal bolt hole.

And let’s not forget the left side. Same story.

I don’t have any pics of my next task, but with my top horizontal bolt holes drilled, and thus the top side of the engine mount configuration locked in, I spent a good half hour aligning the bottom engine mount tabs (using a squeeze-handle style clamp) so that the engine mount aligns leaning forward 2° at the top, which is the plans position.  Again, however, the plans was set up with a 118-125 HP O-235 motor in mind, while I’ll be pushing 180-190 HP.

However, after rereading Dave B’s account on setting his engine mount, I realized that I had misread what my fellow Long-EZ builder had ascertained about the translation of the 2° figure.  So, in the end, knowing that I wanted the aft side of my engine just a hair lower than that of an O-235 Long-EZ, I replaced the typical 1/4″ spacer at the top the engine mount when measuring for this 2° angle (derived during the build by setting the plans F.S. for the bottom mount at 134.45) with a drill bit 0.224″ in diameter.  This engine mount angle and alignment is of course checked by getting 90° on the level with the bottom against the engine mount and the spacer wedged in between the level and engine mount at top.

Once I dialed in my engine mount angle, I clamped the engine mount tubes to the lower engine mount extrusions.

I then started drilling the bottom left engine mount vertical bolt hole, which again, the aft bolt holes on the lower mounts are vertical.  I marked my hole from below, and again drilled just enough of a small starter hole to align the bit.  However, that experience alone told me there was no way I was going to drill a hole UP through 4130 for as long I would need to break through this thick steel tube.

So I carefully measured out the tube centerline and extrapolated all that data up to the top of the engine mount extrusion, and drilled from the top down.  Ahh, much easier!

I did use the reamer, not surprisingly with the same underwhelming results as I got on the top side bolt holes.

However, I decided to add a new twist (this is a pun . . . you’ll see!) to the lower left mount tube’s vertical bolt hole by getting the bolt hole just slightly off center.  The “twist” reference above is because the actual engine mount extrusion is slanted just a hair inboard at the top.

Thus, when I drilled straight down I was in fact relationally at an angle on the lower engine mount tube.  Not far enough off center to cause structural concern, especially with this super strong and rather forgiving 4130 steel, I just lose some major style and good craftsmanship points for this “infraction.”

I then grabbed a quick dinner with an old military buddy of mine and when I returned I pulled the peel ply off all my cured Clickbond install layups… which all turned out pretty good.  Here’s the SD-8 relay mounting Clickbonds on the underside of the CS Spar.  BTW, I positioned these forward enough to be out of the way and not induce any added hassle when I layup the corner BID tape between the forward side of the firewall and the CS Spar

Here are the cured BID layups for the lower right (upper pic) and left brake line securing Clickbonds.

Tomorrow I’ll continue with my engine mount installation, although I will need to assess my reamer issue.  I think I’ll try drilling out the lower right extrusion’s vertical bolt hole with just a 1/4″ bit and see what kind of result I get (obviously builders have been doing this for years with no reported adverse affects).

Well, after about 6 years I finally finished Chapter 14!  Woo-hoo!

I started off by drilling the aft vertical bolt hole on the lower left engine mount extrusion up into the Spruce hardpoint that is imbedded in the CS Spar at all the extrusion attach locations. I double checked my marking that I had made a couple of days ago and then took the plunge!

As you can see, it popped through inside the CS Spar at the tail end and center mass in the Spruce hardpoint.

And I got the same result on the right side as well . . .  I was definitely starting off the final step of Chapter 14 right with the first bolt hole attempts.  Since these 2 bolts are situated so close to the CS Spar’s critical lower spar cap, I knew after I avoided hitting it that the bolt installs would only get easier from there.

Then, out of nowhere, as I working in the Hell Hole, minding my own business . . . Bam! An early casualty . . . ahhh, precautionary tale: THIS IS WHY I PEEL PLY!!
[Obviously this was in an area I couldn’t reach to peel ply!]

After getting the vertical bolts installed, and just as I finished drilling the aft side hole in the lower right engine mount extrusion, it hit me that I was forgetting something!  Ahh, Terry Schubert would be sooooo ashamed if I forgot to seal the wood inside the holes!

So I pulled out the front vertical bolt on each side and left these aft side holes (I had already drilled the outside access for the wide area AN970-4 washers… below) open.  I then mixed a small batch of epoxy with fast hardener, added a bit of alcohol to it to thin it out, and then used Q-Tips to get the epoxy slathered onto the bare Spruce inside each hole.  I also treated the holes in my longerons for my rollover assembly.  I then went upstairs and cooked a fairly quick dinner, took a break, sat down and had a bit to eat.

When I got back the alcohol-epoxy solution was just starting to gel slightly.  So I installed the 2 pairs of bolts into the open holes, pulled the aft vertical bolts and hit those holes with the sealing epoxy solution.  I then drilled the front side bolt holes on each side.  It took a while for me to drill out the front holes, so a bit after I was done I hit the forward pair of the side holes with the alcohol-epoxy solution and then replaced the aft vertical bolts.  Wood holes sealed!

Backtracking a tad, here I’m drilling just the outer sidewall skin and a bit of the foam in order to remove the plug . . .

that would allow me to create a nice inset to employ an AN970-4 wide area washer in an area –the exact area as the gear mounts in fact– that is just fiberglass over Spruce. Knowing the issues I had with the narrow washers and bolts digging into the glass & wood, deforming both, in my original main gear mounting, I definitely want to avoid that where my engine mount is concerned.  Thus, just as I did on top extrusions, I’ll again be using AN970-4 wide area washers.

I then mounted both sets of side bolts for the left and right lower engine mount extrusions. I will note that the forward bolt overlaps about a third-to-half of the way into the area that I dug out to install the wide area washers for the top main gear bolts, as is easily seen in the pics below.  Again, since the underlying glass and wood was deformed a fair bit on the main gear outboard bolts, I used a bit of flox and BID to add some structural integrity and solid underlayment for the gear wide area washers (again, this was for the main gear bolts).

I said all that to merely state that, unlike the aft extrusion bolt, each of the forward bolt’s washer has a lopsided “floor” or “wall” to rest upon since theres a build up of glass and flox on the bottom side of each hole.  To remedy this, I simply added a bunch of thick flox behind each of the 2 forward extrusion bolt washers.

While the flox was curing (I used fast hardener of course) in the forward side pair of extrusion bolts, I took the opportunity to snap some pics of the completed install of the lower engine mount extrusions . . . thus completing Chapter 14!

Here’s shots of the interior bolts (4 each) of each side of the lower engine mount extrusions.

And a shot of the whole shebang!

It’s rather interesting how actual little info there is on this step in the plans.  Knowing I didn’t want a huge gash on my arm as I stuffed goodies into the stowage access hole of the CS Spar before a flight, I decided to mount the vertical bolts with the heads inside the CS Spar and the threaded arm-mangling part of each bolt on the bottom (Hell Hole) side.

I should say that I’m really happy with hitting the CS Spar’s embedded hard points.  I did very slightly cheat on the front bolts and moved them aft around 0.070″ to 0.1″ to ensure they were on the flat part of the spar (both top and bottom on the front of the CS Spar has an angled corner).  This also helped ensure that I could fit a AN970-4 wide area washer in these locations as well.

After the flox –serving as the AN970-4 leveling base in the front side holes– was very close to being cured, I snugged down all the side bolts just a pinch and then micro’d in foam plugs I had just made specifically for this purpose.

I’ll let these dry overnight, then sand them flush with the sidewall.  However, I probably won’t glass them until I build the strakes and add a bit of glass and Kevlar to the sidewall area near the main tank fuel flow feeds that are embedded in the fuselage sidewalls.

Here’s the tally on how many plies I used on each engine mount extrusion BID pad.  As you can see, I met the 7-ply minimum criteria spelled out in the plans.

Tomorrow my main goal is to get the engine mount drilled and mounted onto the engine mount extrusions.  After I finish that task I will then install the engine mount onto the engine and then start planning on exactly how to attach that whole monstrosity to the engine stand.

Today was all about getting the lower engine mount extrusions installed.

I started off by checking the firewall to see if it was 90° vertical, which of course it wasn’t.

The front tire was really low, so by adding air to get if full, and adding one small piece of 3/8″ wood underneath, I got the firewall “zeroed” at 90°.

With my firewall dialed in at 90°, I then removed it and clamped the engine mount in place on the upper engine mount extrusions.

I then checked the plate that I bolted to the firewall last night.  With just a scant bit of downward pressure I can get it to my targeted 1.4° slant with no real difficulty.

Over the next couple of hours I then floxed in the 2 WA16 Spruce wedges and covered both of those –respectively– with 2 plies of BID that covered the entire WA16 and overlapped onto the sidewall, spar and back seat.

I then added the remaining plies of BID to the lower engine mount extrusion pads, 9 plies on the left and 8 plies on the right.

Here’s a pic of the right side WA16 floxed in place with the associated BID laid up in place.

And here’s the same on the left side.

I then slathered up the just glassed BID pads with copious amounts of flox, applied fresh epoxy to the mating surfaces of the lower engine mount extrusions, and then set & clamped them into place on each side.

I then used a pre-cut 2×3 with a wedged 2×4 to keep the forward side of the lower engine mount extrusions pressed up tight against the BID pads.

I then double-checked that all the dimensions were good.  Here’s the right side lower engine mount extrusion in place.

And the left.  As you can see, I peel plied all the BID pad edges that were lined with flox for a nice smooth edge.

Here we have the installed lower engine mount extrusions, shown from the left side.

And the same thing again from the right.  It took me about 6 hours total to finish this step.

Tomorrow I’ll drill the holes through the lower engine mount extrusions to then bolt each on to the CS spar and lower longeron piece.