Project Update

Hey Guys,

Currently working to knock out the strakes (Chapter 21).  The plan is to get the bottom skins on and then flip the bird to glass those bottom strake skins.

However, prior to flipping the bird I will take a few days to finish up the nose and aft nose/avionics cover install.  

Then, once the plane is upside down to finish the bottom of the strakes, I plan on knocking out a whole slew of things while it’s inverted: including bottom strake-to-bottom wing intersection finishing, hell hole cover, belly RAM air scoop, main gear leg-to-fuselage interface, firewall trim and lower cowling install.  Yes, I expect this bird to be inverted for about a month before it gets flipped back upright to close out the strakes with the top skin install.

At that point it will be on to the winglet/rudder install (Chapter 20).  Then engine and upper cowling install, finish and prime/paint.

 

Chapter 21/22 – Daily strake layup

I started out today by pulling the peel ply, trimming the edges and cleaning up the 1-ply BID interior layup on the left strake top skin core.

I then got busy on the right strake top skin foam core.

I measured and marked a line 1.3″ aft of the line I had scribed following the front face of the CS spar.

I then trimmed the aft edge at this new 1.3″ line.

As I did on the left side, I flipped the foam core right side up and marked a 0.3″ reference line from the aft edge.

However, this time I went back and remeasured the top bevel of the CS spar.  I was getting about a 1.2″ wide bevel vs the 1″ I had quickly measured before.  I thought I would try using the entire 1.3″ initially for the bevel on the foam core and see how that went.

Well, that exercise told me two things.  First, about 1″ to 1.1″ works best on the top foam core bevel, so I adjusted it as needed.

The second thing was it was clearly time to knock down the tops of the ribs where they intersected the CS spar so as to ensure the top skin aft bevel mated correctly with the CS spar bevel.  So I spent about 45 minutes trimming and sanding the strake ribs and baffles on both sides to get them ready for both the top skins, and the T-Hat layups.  I don’t have an end-result shot here, but will point that out as I’m working the T-hat layups.

Another issue I had was when I test fitted the left strake top skin core.  The outboard edge (blue arrow) was barely fitting and something was knocking the entire skin core outboard by about 1/8″.  I found the culprit to be the inboard BID flap that is required per plans to come up from the bottom skin and overlap along the top surface of the longeron (yellow arrows).

The problem is that when getting all the glass wetted out along the edge of the underside skin layup, invariably some epoxy goes past that edge.  Thus, along about 2/3rds of this unwetted flap is a hard cured overflow edge that is —not surprisingly— about 1/8″ wide.

The original plan’s method has you glass the top skin then mounting it while the epoxy is tacky, so this flap edge isn’t really an issue. But if you let the skin cure fully then the problem I discovered rears its ugly head.

However, in looking at other builder’s sites I found that Ary Glantz found the solution to this problem: he glassed the underside skin sans flap, then simply laid the glass up (all but the aft 9″) on the LONGERON side first, let it hang down, then mounted the top skin.  Once the skin was in place he simply folded that flap up under the top skin and was done with it (all but the aft 9″ being in the accessible baggage area).  A big thanks to Ary for such a simple solution!

Since my seat cores are back at Oregon Aero getting upholstered, I then threw a seat pad into the back seat and sat back there to assess possible mounting locations for the GIB map light.  If I was going to have it attached inside the strake opening —which I’m not after looking at it— I would have created a hardpoint or embedded a nutplate assembly on the bottom surface of the right strake top foam core.  But I determined that to actually be usable as a map/reading light it needed a bit higher… like shown here on the longeron. Again, my main concern at this point was determining if I needed to do anything to the right strake top foam core in regards to securing the map light.

I then grabbed this shot as I was climbing out of the cockpit,  Note the fuel site gage laying on the left strake top.  I also played around with the positioning of those as well and have an initial idea where I want them… the fairly typically spot they go.

I then cut the big pieces of BID and prepped the peel ply for the right strake top underside layup.

Many hours later this was the end result (think I had a dirty camera lens . . .). This clearly meets my current one-strake-skin-layup-per-day requirement (grin).

With that I left this to cure overnight.

Chapter 21 – Left strake top skin

Today was all about the top left skin, although admittedly I had planned to do a whole lot more.  Funny how these builds work out with getting much less done in a day than planned!

I started out by setting up a workbench outside since my shop is a bit crowded at the moment.

As per the Feather Light leading edge strake kit instructions that I have on hand, I marked a line 1.3″ aft of the aft line I had marked on the underside of the left strake skin foam core. The marked line follows the very front face of the CS spar, so that for the matching bevel angle to be made on this foam core aft edge, it must have a reference…. hence, the initial CS spar face line.

I trimmed the aft edge of the left strake top skin foam core at this 1.3″ line, and then flipped the top skin with the top side up.  I then marked a line 0.3″ forward of the aft edge to use as yet another reference line.  The actual aft edge bevel on the CS spar is 1″ from the lower edge moving aft, so this matching edge interface needs to be the same on the foam core. (Ok, so initial cut is 1.3″ but it needs to be just 1″ for actual fit).

I then flipped the foam core back upside down and used this new 0.3″ mark to match the top surface (facing down at this point) to the edge of my workbench.

I then used the Fein saw to get rid of a good bulk of foam and followed it up with my goto 32 grit hard sanding block.  This last step I should have thought out better beforehand as I think 32 grit is a bit too harsh on that thin trailing edge. I had a few spots that broke out, but nothing that just a bit more flox (read: added weight) won’t cure. I’ll be more careful and judicious in my sanding practices on the remaining strake skin foam cores.

I then test-fitted my left strake top foam core.  After a bit of minor sanding in the very inboard corner, it fit a treat.

I then spent the next 4 hours glassing and peel plying the underside of the left strake top foam core.  It’s been a while since I’ve done a larger layup and the sheer amount of epoxy used just to glass one ply of BID to a piece of foam is impressive.

After today’s glassing experience, I’m re-setting/lowering my expectations and goals to finish one of these skin cores a day.  With the shaping, glass and peel ply cutting all occurring pre-layup, it’s quite a production all simply to get a ply of BID onto a flat surface. As I told my buddy Marco, these layups are “simple in theory and a prolonged ass-whooping in reality.

And I’m sticking to my story… ha!

Chapter 21/22 – Strake top skins

I actually knocked out the labeling of the Warning Sub-Panel last night after I uploaded my blog post.  Today I clear coated it a number of times as I was working in the shop.

The labels aren’t perfect, even with the clear coat, but since these pics were taken under glaring lights and this sub-panel will be in a more subdued lighting situation under the glare shield, I think they’ll work ok. Admittedly, it is making me rethink the labeling of the instrument panel.

After 2.5 days of cure time for the right strake I removed the cross bar and almost all the securing screws.  This is the first unhindered view of both left & right strake structures installed.

A view from a bit higher perspective to show the strake ribs and baffles.

I then got to work on the left strake top skin foam.  I grabbed a fresh* sheet of 3/8″ foam (*that I bought in 2011) and set it in place on top of the right strake.

I then marked a popsicle stick at 0.6″ and used it to scribe a line down the side of the longeron to capture its curvature on the top skin foam.

Here the line is marked and ready to be cut.

I then cut the outer piece and a small triangular piece at the very front for a grand total of 3 pieces to make up the strake top skin foam.

I then micro’d all the pieces together and left them to cure.

I then repeated the process on the right side.

Here’s the right strake top skin foam sheet ready to be trimmed to fit.

After I fit the 3 pieces on the right side, I again micro’d them all together and left them to cure overnight.

Tomorrow I plan on glassing the underside/interior of the strake top skins and then start cutting and fitting the bottom skins as the top skins cure. If time and cure cycles allow, I’ll prep and get the T-hat rib caps laid up on at least one of the sides.

 

Chapter 21/22 – Some strake stuff

Admittedly after some long days I am just beat, and got a late start in the shop.  Where I was checking out last night’s layup when I bumped a portable stand kind of hard and sent my micro’d up Warning Annunciator/Emergency Sub-Panel flying.  I decided right then and there to spend a few minutes to sand down the micro and create a smooth surface for painting… and then for subsequent labeling and clear coating.

As you can see, the right side still has cured untouched micro, whereas the left side has been sanded.

Then over the next few hours I ran through the iterations of a couple light coats of primer followed by a couple coats of matte black paint.  The micro’d/sanded/painted tabs provide a smooth surface to affix labeling to… to then clear coat over for a nice labeled sub panel.

After my initial round of sanding and painting the sub-panel above, I then spent a good bit of time pulling all the peel ply, razor trimming and cleaning up all the right strake layups from last night.

As I did on the left side, I also used the “Fein” saw to trim down the back vertical edge of the GIB strake fuselage opening.  I then sanded it down and glassed it with 2 plies of BID. I then peel plied the layup.

I then did a repair layup on the left side OD rib.  I noticed this when I was horking on the left side leading edge that I cause a slight crack at the top side of the OD rib attach to the CS spar.  Since I had to reshape the nose, apparently I didn’t get it exactly right and with enough pressure on the front of the OD rib it caused a slight separate (about 1/16″ or 0.060″) at the top aft edge of the OD rib.

I removed the glass on the top half first, cleaned up and sanded the remaining surfaces before laying a couple plies of glass back in … with some more flox of course.

Here’s the reglassed outboard side of the OD rib as well.

Kind of crazy how long a few layups took start to finish, but with these in the bag I called it an earlier night.

 

Chapter 21 – Ribs & baffles, Oh my!

Tonight was one of those huge milestones for this airplane build: I finished installing all the ribs and baffles for the right side strake, and thus the entire plane.  Good thing too because those layups spending hours and hours on your knees, trying to jam BID tapes, flox/micro fillets and peel ply back into very tight corners is a backbreaking workout and a half!

Here’s the right strake with the very front duct tape pulled and the R23 rib installed.  Since so much of this strake structure is cantilevered out from the CS spar, I’m giving the right strake —as I did the left— 3 entire days to cure, as I leave all the leading edge to ribs/sidewall screws, duct tape and wood support clamps in place.

Here’s a higher angle shot of the R23 rib installed into the right strake.  I have to say that I’m very pleased that the elevation of the right strake at the R23-leading edge intersection is within 0.050″ of the left strake…. not bad!

And outboard/inboard shots of the leading edge side of the R23 rib install.

And outboard/inboard shots of the aft CS spar side of the R23 rib install.

A side shot of the right strake R23 install.

Here we have the DB baffle and extended/modified BAB baffle installed.

A couple aft forward shots of the DB baffle and extended/modified BAB baffle install.

And a requisite shot of the extended/modified BAB baffle through the GIB sidewall strake opening.

Finally, a shot of the installed R23 rib peeking through the front seat strake opening.

I still have a myriad of strake-related tasks to knock out as I move on to the next major structural piece of the strakes: the top and bottom skins.

Chapter 21 – Right strake leading edge

Today I finally finished mocking up the right strake leading edge.  Again, doing this with the wing on presents some challenges, and again, just like the left strake leading edge —try as I might— I couldn’t avoid cutting the outboard end about 3/8″ short.

This time however I was not going to take the time to reattach some of the sliced off pieces before I glass the leading edge into place.  Since I have to remove the wings soon to both put the fuselage in the grazing position to find the low water mark for the tank drains, and glass the outboard ribs, I figure I’ll just wait until then.

The rest of the install was long but straightforward.  This time I used all EZ-poxy to make it easier and more efficient.  I also was able to peel ply the 1-ply BID tapes around the leading edge that attaches to the fuselage.

Here’s a shot from the front of the fuselage.

I’m using flox on the perimeter tank ribs and micro on the R45 rib.  Even though I went with much drier micro this time, it still flowed out in this one spot . . . right out from under the glass.  Yes, it looks sloppy but I think it will work just fine.

Here’s the modified OD rib, which is the outer fuel tank rib/wall on the forward side of the tank.  I laid up a couple plies all the way around, and of course made them very wet.

For some reason this leading edge fits the ribs just a tad differently than the left side.  I tried 9 ways til Sunday to figure out exactly what was causing it, but every measurement and configuration seemed pretty darn close between the sides.  The right leading edge just seems to naturally rotate forward a hair more than the left side…. although admittedly I had to cajole the left a little more than this side.

The result is the aft bottom flange sits a little farther aft while the top flange sits a hair forward as compared to the left side.  The alignment between fuselage and wing looks really good so I pressed forward with the leading edge install.

Then, at the end of the evening I had some left over epoxy and was actually able to glass the inboard side of the outboard rib.  I’ll have to glass that same section on the left wing once I take the wing off.

Here we have the interior of the right strake leading edge as seen from inside the cockpit. I mocked up the R23 rib and plan on glassing that into the strake tomorrow.

And with that, I’m calling it a night.

 

Chapter 21/22 – Left strake opening

Today I started out by soldering in a glass fuse assembly onto the GIB Bose LEMO power wire.  I would prefer to use an ATC blade inline fuse but the LEMO requires a 0.25 amp fuse, which are readily available in the glass version but not so much in the ATC blade fuse format.

Once I soldered the wire I then covered it with red heat shrink.

And then knocked out the other side.

I then spent a bit of time measuring/cutting/shaping a foam bracket to add another securing hardpoint to the 3 fuel lines, all on the front seat right sidewall.

Fast forwarding a few hours, here’s the foam fuel line bracket secured with a 2-ply glass layup: 1 ply of UNI and 1 ply of BID.  Yeah, it’s a bit rough, but it does the job.  I did take a few minutes to clean up the potentially finger-snagging glass after I took these pics.

Along with the composite fuel line bracket —10″ upstream from the previous fuel line bracket located at the pilot seat bulkhead— I spent a few hours finalizing the wiring & cable management at the front seat right sidewall.  This effort resulted in the right side fuselage cable runs complete from hell hole to instrument panel.

Here we have the installed ELT antenna with the actual antenna aerial set inside a painted 1/8″ Nylaflo tube.  I had thought about hard-installing the ELT antenna inside the Nylaflo tube but decided against it. In this configuration this Nylaflo tube allows me to remove and install the ELT antenna when I need to, whereas if I had hard installed it I would have had to do major surgery to remove it if need be.

My final check was replacing the right front armrest to ensure clearance with the upper and lower wiring bundles.

With the main centerline fuselage tasks out of the way, I then turned my sights on the final task of the evening: the left strake fuselage opening shaping and glassing.

Here’s the before pic of the opening.

I then spent over an hour dialing in the shape of the sidewall to continue the angle of the left strake leading edge inboard to the inner edge of the fuselage sidewall.

After I got the sidewall opening edge shaped, I then drilled a couple small holes to allow me to run a couple wire pairs from the aft side over the strake opening (for cockpit lighting) and a pair just forward of the canopy latch opening (for the canopy latch warning switch). Note the wires exiting the sidewall forward of the instrument panel.

After I ran the sidewall wiring I then glassed the strake leading edge-to-fuselage sidewall intersection with 1 ply of BID. I then peel plied the layup.

Quite a few hours later I pulled the peel ply and did a quick cleanup of the layup.

Out of curiosity I checked to see how far into the fuselage this continuing on of the strake leading edge intruded into the interior sidewall… almost 2″.

From here on out my next focus will be on installing the right strake leading edge.

Chapter 21/22 – More strakey stuff

Today I started out by tweaking my task sheet, reviewing the strake build steps and generally just trying to ensure I don’t screw anything up… or forget something until it’s too late to do. Or really friggin’ difficult at that point.

Out in the shop the main task was to finish glassing the modified/extended BAB baffle.

First, I had glassed it on the aft side with a 2-ply BID tape outboard, but still needed to trim a corner off the actual fuselage sidewall and then glass the interior side.  Here’s what it looked like starting out today.

And a shot showing the fuselage sidewall edge that I’ll trim.

And here it is trimmed.  I just set my Fein saw (Harbor Freight version!) blade up against the BAB baffle and simply used it as a guide.  A few minutes later I was done.

I then laid up another 2-ply BID tape using MGS epoxy on this side.  I then peel plied the layup.

Quite a few hours later the layup was cured and I pulled the peel ply and did a quick cleanup.  It looks good and I’m happy with the results.

After finishing the above layup, I got to work sanding down and prepping the front side of the modified/extended BAB where it connects to the R23 rib.  I didn’t get to this layup when I installed the 2 baffles in the left strake since there was a support board hanging down in front of this corner.  When I did the original layup on the other side I could see the flox bead in this corner and actually used my scribe to get in there and smooth it out and clean it up.

This time around I did add some more flox after scuffing up the original, smaller flox fillet. Since this is an internal fuel tank corner on the perimeter I used a 2-ply BID tape here.  I laid it up as wet as I could and also peel plied just the top and bottom strips that will get more overlaying glass.

A wider angle shot showing the entire interior fuel tank side of the BAB baffle.

To reiterate, I am doing a round of final internal cockpit component tasks before I mount the right strake leading edge.  Here are all the wires from just the top wire bundle that I’m sorting out (read: wrangling).

Here’s another shot of these wires.  I included this pic because the right front wall will be a priority to finish up some tasks before the right strake leading edge goes on.  I’ll detail more tomorrow as I get this stuff knocked out.  To be clear, before the right strake LE gets mounted, all the wiring —both top and bottom wire/cable bundles— in this area will be secure and operational up to the instrument panel bulkhead.

I had planned on doing more tonight, but had some personal calls that I needed to take so I lost a good couples hours there… I’ll be back on it tomorrow.

Chapter 18/21 – Left strake verticals

I started off today working on the small diameter 1/4″ fuel tubing that vent each GIB thigh support sump tank into the main tank.  These guys, left and right, have been sticking up like little flag poles since the day I installed them.

Before it gets a little too tight in that back corner –once I install the extended BAB baffle– I wanted to bend them 90º and trim them down in length.  I was actually thinking of securing them to the side wall at this point, but since I’m going to add a layer of BID over the existing corner I figured I’d wait.  And I’ll still have decent access to that back corner for glassing by coming in from behind the CS spar.

Here are the 1/4″ thigh support sump tank fuel vent lines bent 90º and cut to length.

I then spent the next 3 hours + prepping and installing the extended BAB (inboard) and DB (mid tank) baffles.

A couple shots from below . . .

I used the plans layup schedule with just 1-ply BID tapes to secure the pieces together, both for the rib attach and now the baffles too.  However, where the junction is on the external perimeter fuel tank wall I use 2 plies on the interior tank side just to ensure I have no leaks.

For example, the leading edge “nose” of the R45 rib only got a ply on each side, whereas the inboard leading edge “nose” of the OD rib got 2 plies, as did the outboard edge of the R23 rib “nose.”  For these 2 baffles only the extended BAB got 2-ply BID tapes on the internal side since it makes up part of the perimeter wall of the fuel tank.

Here’s a shot of the baffles looking inboard.

And a couple shots looking aft.

Here we have the extended BAB and DB baffles installed, viewed from the cockpit side.

And a last shot of the extended BAB —due to the “GIB elbow room mod”— from inside the cockpit.  If you look at the aft/left end of the BAB you can see that I still need to trim down a small wedge on the fuselage sidewall aft opening, sand a nice smooth transition and then glass that back corner.  Here I will be using 2 plies of BID since this back corner is also structural.

Before I remove the duct tape from the outside of the left strake leading edge I wanted at least some internal glass securing the LE to the fuselage.  I have glass on the external side, around the perimeter of the LE where it mates to the fuselage, but had nothing internal until I used the Fein saw to knock off a bit of the sidewall edge and then sanded a nice transition from the exposed screw aft.  I laid up a ply of BID and then peel plied it.

Unlike the plans version, a nice feature on these leading edges is that you get a nice curved wing-leading edge-shaped entrance into the cockpit vs. a blunt squarish presentation. However, it will require trimming away a lot more of the inside edge of the sidewall to continue the angle of the leading edge all the way inboard for a seamless transition.  So this was just a quick fix before I knock the rest out (at least plan to) tomorrow.

In addition, since I still have better access to the front seat area with the right strake leading edge not mounted yet, I knocked out glassing the exposed top edges of the pilot seat.  If you’re wondering why I didn’t do this earlier before I painted the cockpit interior, so am I… Doh!

My last task of the evening was finally adding in the #4 hardpoint for the canopy handle lever assembly.  Since I ran the Nylaflo wire transition through the bottom edge of the canopy handle fuselage opening, I was then cleared hot to get this RivNut floxed into place.  I carefully drilled and then prepped the hole before bolting the RivNut to the pre-taped (to protect against errant flox gunk) canopy latch handle.  I then slathered up a bit of flox in the hole and on the RivNut and simply bolted the latch handle back into place. Voila!

Tomorrow will be a bit more work in the cockpit area since my time for unhindered access is coming to a close.  My plan is to either fit and mount the right strake leading edge, or at least have it prepped for install the following day.  Either way, I’m happy to be having significant movement on the strake build!