Chapter 13 — Nose Wheel Cover Insulation
3 May 2018 — Today I started in on the process of adding a thin ply of insulation to the nose wheel cover (NB). As I assessed adding insulation to NB, I decided I didn’t want to run the wires for both the 12V cigarette lighter charger (left aft side of NB) and the USB charger (right aft side of NB) in a circuitous manner. Instead, I wanted them to go as straight from Point A to Point B as possible, which means running the separate set of wires under the lower edge of the NB insulating material at/in the intersecting corner of NB to the fuselage floor.
Since the cigarette lighter adapter also serves as my PC680 battery charging port, and is subsequently connected to the Battery Buss, I used 16 AWG to ensure a robust connection. I terminated the charging port end with the PIDG Fast-ON terminals included with the charger, twisted the wires together to mitigate any electromagnetic noise, and then labeled the wire pair.
I then did pretty much the same thing on the USB charger side (right) only with 18 AWG wire.
I then measured, assessed, determined and drilled the 3 holes required for the 3 separate OAT probes I have for the panel: 1 each for the HXr EFIS, 1 each for the Mini-X EFIS, and 1 each for the MGL Clock/OAT. I emulated Marco in his placement of his OAT probes since on the forward side of NB the OAT probes remain internally clear of the nose wheel when it’s retracted. I wanted the OAT probe mounting holes situated in this location to provide a glass-to-glass bond to secure the NB insulation in place.
4 May 2018 — Today I focused on the USB charger bracket, which is the twin of the left side nose wheel cover cigarette lighter charger. My front seat USB charger will be located at the intersection of the nose wheel cover (NB) and the lower instrument panel’s center strut, on the right side… about as close the gear viewing window as you can get. As I see it, this is otherwise dead space so a good corner spot to stuff something into.
I spent well over 2 hours on this USB bracket today, starting off with a good 45 minutes of trial and error measuring, test fits, mockups and tweaking to get the final USB charger’s bracket –which is a tad bit bigger than the cigarette lighter charger’s bracket– cut and drilled to the right shape and dimensions. As you can see, the USB charger bracket was cut out of my 1/16″ phenolic stock.
I then sanded down the 1/16″ USB charger bracket to prep its surfaces for glass.
I then 5 min glued it in its place at the aft corner intersection of NB and the lower instrument panel cross piece.
I then prepregged and laid up 2-plies of glass top (I used scrap glass, so 1 ply BID over 1 ply UNI) and 1 ply of BID on the bottom side. I used small flocro fillets for the corners, heavier on the flox. I then peel plied the top side layup.
I then went out to dinner with my buddy Rob for a couple of hours while the glass cured. When I returned I pulled the peel ply, knife trimmed the layup and then sanded the rough edges to clean it up.
Here’s a shot of the lower layup… this is the first I’ve had eyes on this bottom layup since I did it all by feel the when I laid it up initially. I intentionally drove the fillet away from the spot where the mounting hole is closest to the NB side to allow room for the large plastic mounting nut that secures the USB charger in place. Of course viewing this pic did identify one more spot that I needed to knife trim.
And Voila! Here’s a test fit of the USB charger . . . fits like a champ!
With the USB charger bracket mounted in place, I can press forward with my plan to insulate the nose wheel cover and secure it in place with a ply of BID.
6 May 2018 — Today I got busy insulating the Nose Wheel Cover (NB). After thinking about it a bit I decided to insulate NB in 2 phases, the front 2/3rds section and then the remaining 1/3 aft section. By doing it this way, it allows for more glass-to-glass contact and secures the insulating material better in place… IMHO.
I also split the 2 sides so to create a narrow trough down the center which would be a low-point depression in the insulation to ensure clearance for the bottom edge of the Triparagon when it’s mounted in place. Again, it would also provide a glass-to-glass securing point down the centerline of the insulation.
After giving the NB and surrounding fuselage floor a thorough sanding, I started by cutting to shape and then using Silicone RTV to secure the insulation to the right front 2/3rds of NB. Remember, I’m cheap . . . and if you want to be read in on a little secret: this insulation is the flooring material underlayment I bought in Germany to use as a hot-tent for post curing the fuselage back in 2012! Ha!
You can see that although this insulation is somewhat thin, it still has an edge on it.
I then cut to shape and RTV’d the left front 2/3rds insulation in place on NB. You can see I used the attached nylaflow –that runs partway up NB at an angle for the parking brake cable– as the demarc point for ending the first round of insulation, with the underside getting insulted in phase 2.
Here’s another shot of NB’s front 2/3rds area insulated and ready for a 1-ply BID glass covering.
I then whipped up some epoxy (with fast hardener) and micro’d the edges of the insulation and the intersecting corners of NB and the fuselage floor, where the respective pair of charger wires run along each side.
I then laid up one solid ply of BID across the entire front 2/3rds area of NB covering the insulating material I had just RTV’d in place a bit earlier. To keep the glass in the narrow center trough between the 2 pieces of insulation in contact with NB for a good glass-to-glass bond, and as deep as possible for clearance with the Triparagon, I took a length of plastic tubing (that was used for the gear leg conduits) and pressed it down over the peel plied center trough. To keep the plastic tubing in place I of course had to come up with some clamping contortions to do so.
I also peel plied the glass-to-glass bonded patch where the 3 holes are for the OAT probes. I then filled an ACS baggy with sand, taped it up and set in place on the glass-to-glass bonded patch to compress the glass down and ensure the best possible bonding. I leaned the 90° drill on it to keep the mini sandbag in place and add as much reasonable weight as possible.
I then spent a number of hours on the phone with fellow Long-EZ builder Brian Ashton from Alaska, and after sharing our war stories and build progress, I then went downstairs to the shop and pulled the peel ply and cleaned up the layup.
I didn’t see any issues whatsoever with the layup and am extremely pleased with how the first phase of my NB insulating came out. As for the respective set of charging wires, I’m typically NOT a fan of burying wires under glass or micro, but here the runs are so short that if I did have a problem I could use the Fein saw to dig them out. I oversized the wires simply to avoid any potential problems and to handle any added heat (negligible IMO) by being encased for about a foot in a ply of glass and some micro, so I really don’t foresee any issues.
7 May 2018 — I started out today prepping for glassing up the last third of nose wheel cover on the aft side.
I started by dialing in the shape and cutting out the top aft “saddle piece” — that just happens to be a bit “New Jersey” shaped in my book– that will make up the first of the last 2 pieces of insulation that needs to go onto NB to finish up the actual insulation part.
I then RTV’d the top “saddle” piece of insulation into place on the aft side of NB.
On the left side of the top “saddle” insulation piece it mates up with the front 2/3rds insulation and ends just above the cigarette lighter mounting bracket. I then added 2 more pieces of insulation below that to fill in the triangular area on the left lower aft side of NB.
Since clearance is tight in the areas of both chargers, I left the very lower aft corners of NB bare.
On the right the top “saddle” piece of insulation covers the last aft 1/3 of NB down to the fuselage floor. It of course also mates up with the front 2/3rds NB insulation.
I then micro’d the edges of the new NB insulation pieces on right side . . .
and the left side.
I then glassed up the last of the uncovered insulation on NB using 2 separate pieces of BID to create a 1-ply covering that overlaps right around the mounting tab for the parking brake on the left side (close to where the intersection of the “saddle” piece of insulation meets the bottom aft piece).
I then peel plied all the intersections, overlaps and edges of the layup.
After taking a short break, when I returned to the shop my final NB insulation layup was pretty much completely cured. I pulled all the peel ply and then did a rough clean up of the layup by clearing/cutting out all the holes I had covered up with the layup. In fact, 2 mounting tabs: the right side USB charger mount and the parking brake handle mount both got an extra ply of glass added to them for strength (and ease of laying up the insulation covering BID).
Here’s the final shot of my NOW insulated Nose Wheel Cover (NB)… which I of course quickly marked that off my to-do task list!
I will repeat and alas, reiterate, that completing these prerequisite tasks personally does not get me jazzed like seeing the big “real” pieces of the airframe go together, but in my attempt to stay disciplined by front loading these tasks and doing them while I still have true access to these areas that would be so much more difficult to reach in the future, I truly believe I’m optimizing my build sequence as best possible…. although it may not seem fun or sexy right now! (for any of us!)
[Note: I’m adding this initial coverage of the nose wheel cover painting here, but this will also be covered in Chapter 25 as well. There will be no more coverage on paint/finishing included on this page].
9 May 2018 — Today I spent a good 45 minutes prepping the avionics bay between the panel and F22 bulkhead for paint.
As you can see, I eventually just created a large box by sealing off the leg and other smaller holes on each side.
After everything was taped up, I shot the nose wheel cover and surrounding avionics bay area with some self etching primer.
After the primer cured, I then shot the nose wheel cover and surrounding avionics bay with Duple-Color trunk paint (yes, folks, TRUNK paint . . . ha!).
I tried to lay the paint down in 2 lighter coats, but there were a number of odd angles where I had to get the can in closer then I wanted…. and it laid a much heavier, sloppier, wet coat in those areas. Luckily this paint proved itself as the forgiving sort and self leveled as it dried.
It may be odd, but having grown up the son of a cabinet maker and carpenter, and doing a fair amount of wood working myself, I just couldn’t bring myself to cover up what I think is a really cool build aspect of these planes: the triangular Spruce stringers in the lower fuselage corners. With the clear MGS that I use it looks like a bare wood strip down there and the hash cuts we make at intervals to install them is just a fun design feature in my book. So… I covered each side’s stringer with tape to protect it from paint…. call me crazy! (I prefer “eccentric” . . . ha!).
I carefully pulled out all the cardboard blocks and removed the protective tape from all the wires, cables and components. Yes, I’ll admit the majority of this painting endeavor is for simple cosmetic reasons. There was some junky looking spots I had going on here, and for the most part I try to avoid adding weight with paint. Also, as you can see by my stopping point on the sidewalls, it really is for the view that we see when peering into either leg hole.
Here I covered up some unsightly areas on the aft side of F22.
And here we have the left side foot heating vent duct with attached SCAT tubing. I have to say, I’m really digging this paint color!
My decision in painting the sidewalls and some of the floor was a bit of scope creep in my initial task of painting the nose wheel cover (BTW, I couldn’t bring myself to remove the duct tape for the eventual anti-skid inserts off the floor just yet… it looked too good and I didn’t want to spoil it!). Clearly (IMO anyway) I couldn’t NOT paint the insulated NB cover. Although an unpainted NB cover would have been an interesting discussion generator, it badly needed a good color of paint on it (again … IMO).
You can also see that my personal preference is to leave components their natural color if I can. I see a lot of canards where once all the wiring and hardware is in, then it all gets blanketed with a coat of paint. I think that style looks good as well, and serves to clean up & declutter the fuselage visually… I just prefer to preserve components sans paint if I can.
With the USB charger bracket and surrounding area finished to paint, I decided to go ahead and quickly install the USB charger port in its bracket and connect the wires.