Chapter 25 – Left wing delam

I started out today putting all my efforts into finishing up the bottom of the left wing.

When I installed the winglets onto the wings I had 2 functional wing dollies, but since I have no room inside my shop they’ve had to live outside in the weather.  The one wing dolly I’m using here, although weathered and unsightly, is still operational. The other one (much older of the two) is rotting out in spots… in short, with only one wing dolly I have to get the left wing finished to get to working on the right wing.

I first spent over half an hour doing a final sanding on the micro finish of the outboard bottom wing, bottom inside winglet and bottom winglet intersection fairing. I had a number of major divots from air bubbles in the micro, as well a myriad of smaller yet distinct depressions and holes as well, which I remedied with a quick round of micro & West 410 mix applied to these offending aberrations.

I then got to work on the left wing aileron pocket’s bottom lip, sanding it for about 45 minutes to widen the gap between it and the front lower edge of the aileron (which is the embedded aileron weight rod).  I was able to sand the aileron pocket edge away to give me a hair over a 0.1″ gap, with the minimum per plans being 0.08″.  Obviously, I want to have a little extra to allow for paint.

I had other tasks on my list that I had planned to work on, but it looked for a few hours that a thunderstorm might be passing through, so I continued to focus on the wing.

Sins of the past….

My next task on the bottom of the left wing (once again moved outside in front of the shop) was to A) do a final sand on the previously boat-paint-primed bottom surface, and B) remove as much of the boat paint primer as possible since I’m now going to shoot the paint vs roll it on.  I will note that this primer is as hard as nails and takes a good bit to get it removed.

Moreover, as I was working near the inboard edge, I found a linear bump that after further investigation was clearly a delam.  My guess is that when glassing in the extended lip to attach the oil cooler I must have set a heat lamp too close and caused this delam… but I’m not 100% sure.

After doing a bit more aggressive sanding to get down to glass, I used both a large washer (quarter tapping) and pushing with my fingers to find the area of the delam, which it certainly was.  You can see the ridge marked above and with the ruler “riding high” in the pic below.

With it being a longer narrow delam, I drilled 4 holes down the center, and a couple more holes with one on each side of the perimeter. I then mixed up some MGS 335 with fast hardener and injected the epoxy into the holes.  I had both a taped up long narrow block and my clamp ready to go, which I employed immediately following the epoxy injections.

Another shot of the inboard bottom wing delam repair: clamp securing taped block in place.

After dealing with the delam, by this point my added micro to outboard bottom wing micro’d areas was cured.  I spent another 30 minutes sanding all that down so that this area is all ready for epoxy wipes.  But as it was past 8 pm, I punted on the epoxy wipes until tomorrow.

I then spent another good hour sanding the boat paint primer down on the bottom of the wing.  Here’s a shot of where that took place outside the shop.  I’ll note that I tried using both my air file and electric orbital sander but found that what worked best by far in this task was my new jitterbug pneumatic pad sander.

Here’s a better shot of the primed and now sanded left wing bottom surface inside the shop, under the lights. I will probably do another good round of sanding towards the middle outboard area of the wing, since there’s still a few shiny spots that can be seen under lights.

And yes, I will incur a slight weight penalty by not removing all the primer completely, but I’ll note first that it is serving as a filler in leveling out the high and low spots on the bottom surface of the wing, which under the lights and to the touch is very uniform and smooth.

Secondly, I am pushing hard to get this bird done, thus time is of the essence.  Sanding down this primer takes a fair bit of time, and more importantly I don’t want to do any damage to the finish of the wing or have to start over in the finishing process due to excessive removal of the primer.  I’ll take the slight weight hit and press forward.

Chapter 25 – I hate sanding.

But it is quite the necessary evil if one is building a Long-EZ, eh?!

So today I had to bite the bullet, quit my belly-aching, and get to work sanding down all the epoxy wiped areas on this bird.

I started out with a couple hours of sanding down all the epoxy wiped areas first with 150 sandpaper dry, followed by going over the same areas with 150 grit wet sandpaper.

Here we have the right longeron exterior sanded to 150 grit wet and ready for primer. That being said, I will need to do a bit of cleanup on the inside areas once the canopy comes off, when I have full access to the right longeron just under the canopy lip.

Although my persistent problem area is much less egregious, the right sidewall still had a number of shiny spots (depressions) that I felt needed to be dealt with now, prior to primer and paint.  So I marked the areas with green tape for another 3-5 coats of epoxy wipes to level them out with the surrounding surfaces.

I will say that the right top side of the nose turned out nice after a round of dry sanding, then wet sanding…

as did the left side as well.  Yes, the nose is looking good with minimal defects and is ready for primer and paint!

I then wheeled the left wing pallet dolly outside to minimize the dust from sanding the just-micro’d outboard underside wing, winglet and intersection fairing.

But first, I used a ruler to check the elevation between the bottom wing surface just forward of the bottom aileron surface: inboard, middle and outboard.  All looked good, or at least acceptable in the case of the outboard elevation.

I then checked the gap between the bottom wing aileron pocket edge and the front bottom edge of the aileron.  The plans say 0.08″ minimum to 0.2″ maximum.  I’m clearly towards the minimum side (which is good in my book) with all the blue areas below denoting less than 0.08″ gap.  Clearly I need to do some judicious sanding along the aileron-wing aileron pocket edge… all on the wing side.

While sanding the aft end of the right longeron, I also checked the quality of the surface of the Turtledeck… well, it wasn’t as smooth as I remembered.  Where I had to do subsequent micro fills, there where elevation differences at the seams of old and new micro.  So after a good bit of sanding (which helped a lot) I decided to slather on a few good coats of epoxy to help even out the surface: 5 coats to be exact (pic 1).

I also use the mixed epoxy to hit all the very slight low spots on the right fuselage sidewall.  Again, 5 coats (pic 2).

Outside I spent nearly 2 hours doing the initial sanding on the left bottom outboard wing, the inside bottom winglet and the bottom wing-winglet intersection fairing.  I’d say I’m at least 80% finished.  But it was getting late so I wheeled the wing back into the shop to finish up the fine-tune sanding tomorrow.

Here’s another shot of the initial sanding of the left bottom outboard wing, inside bottom winglet and the bottom winglet intersection fairing.

My goal is to finish up the left wing tomorrow and get cracking on the right wing.
Rock on!

Chapter 25 – Left wing micro-finished

Last night I knocked off about an hour earlier than I normally do to fill out the paperwork to get a new passport, since I need to travel to California for a reunion next month and also plan to travel out of country both with the new Long-EZ and overseas for some adventures with Jess.

My passport appointment was late morning, so before I left I wanted to get a task or two done as I let last night’s layup cure a bit more before I pulled the peel ply.

I turned my focus to the aft upper lip of the left strake where I had laid up 2 plies of BID on the underside of the lip.  The lip trailing edge had a fair amount of dings on it, so after I trimmed the cured overhanging BID a bit I then added some flocro to these aforementioned dings, etc. (pic 1).

Trimming the remaining glass and sanding it all nice and straight was a perfect task for this morning, so I knocked that out and was quite pleased with the results (pic 2).

After returning home from my passport appointment and running a few errands, I then pulled the peel ply off last night’s layup of the left wing-winglet lower intersection fairing.

Before I snapped this pic, I placed a red zip tie pointing at the plans (CP) position for placing a tie down bolt thru-hole.  But instead of that, I simply embedded a threaded aluminum insert with flox while glassing the wings.

In the future I’ll make up some low-drag tie-down points that I’ll install on each wing at these points.

For now I simply used my drill and carefully exposed the threads (pic 1), and then tried out a 10-32 screw to check that it threaded in nicely… which it did (pic 2).

I then stuffed the threaded insert with plastic Saran wrap and taped off the lower flanges of the wing leading edge light to protect both from the upcoming micro finish.

I then whipped up a few batches of micro (with a dash of West 410) and slathered it all onto the lower outboard area of the left wing, the inside lower area of the left winglet, and of course the added winglet intersection fairing.

I had planned on doing some more sanding on the plane, but at nearly 10 pm it was still about 90° F in the shop … so I called it a night.

Chapter 24 – Quick fairing layup?!

NO!!

Now it wasn’t overly difficult nor was there any issues, but good heavens did it kill about an entire day!

But I digress… let me back up to the beginning.

I started by cleaning up and sanding the area on the left wing-to-winglet intersection fairing —bottom side of course.

To keep the whole fairing light as possible my substrate material is balsa wood.  Thus, to get a good glass-to-balsa wood bond along the trailing edge, I taped in from the TE about 0.5″ to keep the foam off of it.

I then built a taped cardboard dam for my pour foam (pic 1).  Granted, the footprint was significantly larger than I needed, and I put in a LOT of pour foam (pic 2), but at least I never had to ADD any more pour foam: one shot, one kill!

After I let it cure for about 30 minutes, I then spent the next 45 minutes using a hack saw blade and a piece of cardboard tube (from a used up fiberglass roll) I cut and sanded it down to shape.

A bit more fine tuning and it was ready to glass!

And one more shot of the finished foam shaping on the left winglet intersection fairing from the front side.

I then whipped up some wet micro using Pro-Set epoxy and applied it to the entire foam area.  On some spots I needed some thicker micro so I applied that as well.

Before applying the micro I made a plastic sheet pattern about an inch out from the edge of the foam, to allow me to cut the glass. The first ply I cut from a large scrap piece of UNI was about a 1/4″ less around the perimeter (except the trailing edge).

I put the UNI ply in place (pic 1) and then thoroughly wetted it out (pic 2).

The second ply I cut was BID off the roll biased at 45° angle.  I cut this piece about 1/4″ more than the plastic sheet pattern to give me a 1/2″ overlap over the UNI (I like to cover UNI with BID).

I then did the same and put the BID ply in place (pic 1) and then wetted it out as well (pic 2).

I then peel plied the layup and left it to cure overnight.

One departing shot of the left winglet bottom intersection fairing shaped and glassed!

As long as it took it’s rather exciting since I’m truly getting down to only a handful of layups left before the airframe is officially constructed!

Chapter 19/25 – Shop musical chairs

I started off this morning meeting Guy out at his hangar to start the task of reinforcing his right gear leg, that has had a persistent issue with brake heat warping it outwards, causing even more heat issues once the brake rotor contacts the heat shield.

We’ve deduced from a few data points that his ol’ skool football wheel pants are definitely exacerbating the heat issue, since after the first repair things were pretty good until the wheel pants went back on.

So before doing any radical or high cost fix actions (i.e. new gear bow or an aluminum “sock”) I proposed we attempt a reinforcement of the gear leg —after yet another heating and repositioning inward— with a good number of mixed plies of BID and UNI using a high temp resin to help resist any heat damage.  These plies will not only serve to reinforce the gear leg that has had a few cycles of heat⇒outboard, heat⇒inboard, but as a physical insulation to the generated heat.

I started at the top (~10″ up) with a single ply of BID, then starting an inch down from that a double wrap of UNI @ 30°, then an inch down from that a single ply of BID, then yet another double wrap of UNI biased 30° the opposite direction of the first, and then a final wrap of BID an inch down from that.  So 7 plies minimum, with maybe another ply or two one side or the other depending on where the glass wrap ended.  I then peel plied the layup.

After lunch we came back to the hangar, and with the hot days we’ve still been having the layup was in a nice “green” state of cure.  This allowed me to fairly easily razor trim the glass from the lower gear leg where the brake caliper notch is located, as well as along the very bottom of the gear leg.  We then left it to cure for a few days until we get back to it.

I’ll note that in addition to the added glass on this gear leg, since Guy has Cleveland wheels and brakes, the rotors are just uncomfortably close to the gear leg, especially with a heat shield in place.  To help remedy this issue, I’m going to machine a 1/4″ thick spacer to kick the entire wheel assembly outboard and off the gear leg just a bit.  This will also allow us to put a thicker (0.063″ vs 0.02″) heat shield in place that also covers more of the brake rotor to help block the radiated heat.  We’ll be installing these spacers and new heat shields on both wheels to keep them symmetric.

Back in my shop, I got to playing “musical chairs” in moving stuff around and out (canard back in house) to allow me to wheel in my old taller wing dolly… that the wing will sit on upside down as I finish both the bottom side of the wing-winglet fairing and the underside outboard wing/winglet micro finishing.

You can see that I was able to move the nose of the bird away from the plasma cutting table and the whole bird back a few feet to allow me enough space to wheel in the old wing dolly.  That being said, things are still tight back there.

I should note that a bit before my musical chairs shenanigans, I pulled the peel ply off the top lip underside layups of both the left wing and left strake.  I then trimmed the glass a bit and added some flocro along each lip edge where there were slight chips and imperfections.  I then left those to cure. (no pics)

And here we have the left wing inverted on the old, taller wing dolly.  Again, I’ll get to work on the wing-winglet intersection fairing and micro-finishing starting tomorrow.

Yep, slowly pressing forward.

Chapter 25 – Upper left wing/strake lips

Today was all about finishing up the configuration and construction of my wing removal and installation dolly.  And although it required an unscheduled trip to Lowe’s for some hardware, I did exactly that.

Here we have the newly completed wing removal dolly (pic 1), and it in place to remove the left wing (pic 2).

It took about half an hour to remove the left wing as I learned the intricacies of using my new wing removal/installation dolly… since each corner can be raised or lowered elevation-wise using the repurposed trailer wheeled tongue screw jacks.

Not surprisingly, there was a lot of micro dust in the channel between the left strake and wing.

And a good bit at the outboard end of the left strake as well.

I’ll note that before I took the wing off, I inspected the wing bolt lengths inside the wing bolt channels.  Both AN8-22A bolts were about 1/8″ too short, so I swapped them out with some AN8-23A bolts I have on hand.

With the left wing off the bird, I then tried my luck at installing the wing root forward heat shield.  Ahhhh!  As I suspected it went right into place…. note to self!

I have to say that I’m really liking this new wing removal/installation dolly so far, since the wheels allow the wing to be very easily repositioned.  This allowed me to easily open up the gap in between the wing and the strake to then allow me to clear out the tape and foam from just under the top inside edge of the intersection flange on both wing and strake, respectively.

After finalizing the cleanup of the left strake’s aft top lip underside edge, I then filled the corner gap with flocro before laying up a 2-ply corner BID tape to secure the underside aft top strake flange to the aft face of the CS spar.

I then did pretty much the same thing on the top flange of the left wing, laying up a corner 2-ply BID tape overlapping from the flange bottom edge to the front face of the sheer web [I’ll note that I built the wings much earlier in the build than what the plans call for —to use as much epoxy as possible that I bought in large quantity while in Germany. So I was still a very new builder and thus why my wing work is not so beautiful!].

I then spent about half an hour cutting glass that I will layup on the bottom of the left gear leg on Guy William’s yellow Long-EZ (early tomorrow morning).

And with that, I called it a night.  Pressing forward!

 

Chapter 19/23 – Houston: 2 problems

I started out today plotting out the right wing root forward heat shield template to test out the updates I had made to the template diagram.

I had also updated the post processing G-code files for both the left and right wing root forward heat shields, so after I confirmed the right side template was good, I got to work prepping a sheet of 0.032″ thick 6061 aluminum to use to plasma cut out the heat shields (pic 1).

And then cut out the left heat shield first (pic 2).

I then loaded up the right heat shield in my Fire Control plasma cutting software (pic 1) and cut it out as well (pic 2).

And here we have the the left and right wing root forward heat shields cut out of 6061 aluminum.

As a side note, for those interested, my feeds and speeds numbers are about perfect as here are the undersides of those plasma cuts: very minimal dross on the edges.

I had a hunch that this last round of micro additions on the right upper nose, right sidewall and aft right longeron were going to do the trick.  And I confirmed that after a good hour and a half worth of sanding.

I wanted to knock out the sanding at this point in the day (prior to finishing the heat shields), because I was either going to need to add more micro, or finally get to the final round of epoxy wipes on the upper nose, right fuselage sidewall and right longeron.

I did 3 total coats of epoxy wipes, which can be seen in both the pic above and below.

In between the epoxy wipe coats, I was able to get the front and aft tabs of the newly cut heat shields bent as required on the metal brake.

Now, I’ve had a sneaking suspicion that I might have some issues getting the final aluminum versions of these forward heat shields to mount in place vs the thick paper templates, which were way more flexible…. and I was right.  Between tabs protruding from top and bottom, there is clearly a number of CAMLOC receptacles blocking a clean ingress of these shields to get them set in place.

And although cutting the upper corners of the tabs on the left shield allowed me to get much deeper it still just would not set in all the way.  Thus, problem #1.

My thought is to simply get these forward heat shields into place with the wings off, which might lead to another problem—more of a maintenance (and safety) issue if you will: checking the inner wing bolt.  Problem #2.

Currently I have 2 courses of action to remedy the inboard wing bolt checking issue:
A) simply remove the aft heat shield and use a mirror and ratchet extension to check the bolt,
or B) make a small portal with removable cover plate on the heat shields adjacent to the wing bolt.

I’m leaning towards option A to reduce weight, time and effort.

I’ll ponder more on that, but for now I’m calling it a night.

Chapter 19/23 – Yep… heat shields

This post covers the past few days, given we had quite a busy day on the 4th of July, or Independence Day for us ungrateful colonists.

The day before I spent about 4 hours getting the boat ready to take out on the 4th, since I had promised my new bride, Jess, that we could take the boat out for the first half of the day on the 4th.  Then, for fireworks in the evening we had a cookout on a nearby beach and enjoyed those with friends.  That’s my story and I’m sticking to it.

As for the build, yes, I’m still trying to finish up these niggling wing root forward heat shields, although I think I’m very close to plasma cutting them and getting them installed.

My tasks the last few days were all about the same ITERATIVE process for both left and right wing root forward heat shields:

I plotted out the initial right heat shield thick paper template along with the second left side template.

I’ll note that I missed some major dimensions somewhere on the right side when inputting it into CAD, because it had issues.  I simply annotated it compared with the original cardboard template and updated the CAD model… no use wasting time attempting to test fit.

On the left side template, my top and bottom edges were still too big, causing some buckling in the middle areas of the heat shield mockup.  I had a number of tweaks to do on this guy, so back to CAD I went on this side as well.

Which led to the next plotting session, round 2 for the right side (after my initial misfire) and round 3 for the left side…

The left side is VERY close, so much so that I’m not going to remake any more cardboard mockups… a few very minor tweaks in CAD and its ready for plasma cutting (pic 1).

As for the right heat shield mockup, I had a number of significant tweaks that are required (pic 2).  So back to the CAD drawing.

And replot #3 for the right side . . .

And a much better fit this round, but still a few minor tweaks required to dial it in completely.

I updated those needed tweaks in the CAD file, and will plot out another final (hopefully!) thick paper template tomorrow, test fit it and then go from there.

Yes… these darn heat shields (in part due to time off for celebrating Independence Day) are taking way too long.  I really want them done and installed tomorrow.

Rocking on!

Chapter 19/23 – Slow-mo heat shields!

I started off today by removing the aft heat shield on the left wing, then pulled the peel ply and razor trimmed the top and bottom mounting tab glass.

Here’s a shot of the somewhat narrow and tall phenolic bottom tab, secured with flox and 3 plies of BID on the aft side.  I’ll probably add a single ply of BID on the front side.

I then reconfigured my plasma cutting table again as a plotter, and printed out the left wing root forward heat shield mockup on thick stock paper.

After which, I cut out the paper mockup and set it in place in the left wing root.

I should note that I ran downtown for a few hours to run some errands, and during that time picked up two different sizes of plastic grommets for the aileron control tube thru-hole.   This grommet I’m testing below has an inside diameter of 1.0 inch.

In addition, by looking at some bends in the stock paper, you can tell that I need to trim a little more around the edges here and there.  So I’ll tweak the drawing in CAD, reprint and test fit again.

I then made a slew of measurements and constructed an initial cardboard mockup of the right front wing root heat shield.  You can see I’ve already moved the rudder cable transit thru-hole down from its initial position (presence of the green tape).

After getting the rudder cable thru-hole position set, I then opened up the diameter of the aileron control tube thru-hole.  Then, as I did on the left side, I ensured that there was good clearance through the entire control tube range of motion with full left and right aileron deployment.  Full right aileron is shown in pic 1, while the widest part of this aileron control tube is actually a rivet head when the stick is a little past center towards the left (pic 2).

As I mentioned before, I got 2 sizes of plastic grommets while I was out: 1″ ID and 7/8″ ID.  Here I’m testing out the 7/8″ ID grommet, which I assessed didn’t provide enough clearance.

Reading the Canard Pusher and Central States Newsletters, I’ve read a few stories of first flight issues with controls snagging on nearby structures (or thru-holes) with clearances not as big as they should have been to allow for various stresses and pressures during flight.  Thus, my standard for this 1/2″ control tube is 1/4″ all around it. I tried the 7/8″ grommet mostly out of curiosity, and I think it proved my initial minimum 1/4″ clearance requirement was good.

It was getting later in the evening, but I wanted to at least get the initial right wing root cardboard mockup imported into CAD… which as you can see below, I did.  This stuff often takes much longer than expected, and I’m clearly wanting to get it done and in the books to get this bird in the air.

Hopefully tomorrow I’ll be able to get these forward heat shields plasma cut and installed.

Pressing forward!

Chapter 19/23 – More heat shields

I started off today by taking off the aft right heat shield, pulling the peel ply off the new cured upper and lower tabs, and then trimming them with the Fein saw.

Here’s another look at the new upper and lower 90° tabs in the right wing root that will secure the forward heat shield.

I then got to work sanding the current problem areas on the right fuselage sidewall, and some micro fill along the aft right longeron. I sanded all the areas and re-epoxy wiped the aft right longeron and a few spots on the nose, but for the sidewall it needed yet another application of micro, which I mixed up and applied.

Part of my sanding and epoxying wiping tasks was the second round of micro I applied inside the slots across the aft nose substructure just in front of the instrument panel where the 4 tabs on the aft nose/avionics cover drop into to be secured by CAMLOCs thru and around the top of the instrument panel.

I then worked on the aft wheel pants, sanding the epoxy wipes down and then wet sanding them with 150 grit.  I have one small area that needs further work on one side of those (again, no pics).

I then removed the left rudder since when I installed it last I didn’t hook up the actual rudder cable to the bellhorn.  With the cable attached to the rudder bellhorn, I then mounted the oil cooler since the end of the rudder cable bracket is secured to the oil cooler bracket.

With that all in place, and the rudder cable connectors joined, I then simply added a clamp to the nose rudder cable to pull it taut. This provided me the no kidding thru-hole position I needed in the left wing root forward heat shield, which was a good bit different than my original swag.

I then evaluated the position of the other heat shield thru-hole for the aileron control tube with the stick in the full left position/hard left turn (pic 1) and then fully opposite in a hard right turn (pic 2).  As with many things on this plane, the control tube has a lateral movement pivoting aft and slightly down when in a left turn, and forward and slightly up in a right turn.

The next 2 hours were all about setting up, prepping and laying up the upper and lower 90° tabs inside the left wing root, pretty much like I did on the right side.  The big difference that you’ll see when I post next is the bottom tab, which is about half the width of the other tabs since there is a CAMLOC receptacle which I had to avoid just on the edge of the flange.

Thus, for the bottom tab I used about a 1/2″ wide by 1.5″ high 1/16″ piece of phenolic standing on end, which I floxed in place.  I then used 3 plies of BID on the aft side of the phenolic tab that overlapped rearwards onto the wing root surface.  The front of that tab abuts the inside face of the aft heat shield as installed.

I then laid up the top 90° tab the same as I did on the right side, with 6 plies of BID.

I prepped the right wingroot area for creating the right forward heat shield by removing the AP roll servo (after marking the outboard edge which the heat shield flange will have to be notched to avoid), and installing the right rudder cable bracket and cable.  I then removed the right rudder and connected up the rudder cable to the internal bellhorn and reinstalled the rudder.

It was getting fairly late, so I called it a night.  Tomorrow I plan on finalizing both left and right forward heat shields, plotting out templates on the plasma cutting table to ensure they fit correctly in each side, and then plasma cutting them out and bending them on the metal brake for final install.

Again, once the forward heat shields are configured and installed, I am then cleared hot to remove the wings to finish the bottom-side wing-to-winglet fairings and micro finish the outboard bottom wings for primer and paint.