And rights of passage…

Any canard builder can tell you that yet another of many, I guess the grand finale, right of passage in building these birds is the micro-finishing process.

I started off this multi-day process with hitting the left wing and strake tops again with the air file.

This knocked down the micro a good bit more, but still a long way to go on the left side.

Here’s a selfie towards the end of the evening to capture just how amazingly messy this whole micro-finishing affair is all the way around.

I cut to length and ripped on the table saw a pre-primed board to create a stick of pain that is nearly 67″ long, which allows me to attach 4 each ~3″ wide peel-n-stick 36 grit sandpaper strips onto it, end-to-end.  To secure the board’s straightness, and give me a handle to grip, I screwed a 2×2 down the top (which I ripped on one side to ensure it too was straight).

Let the real pain begin!

As a level marker/guide coat I decided to use pencil vs spray paint, mainly because all the paint I have on hand has too long of cure times.  And I forgot to pick up some guide coat paint at the store.

No worries.  I grabbed my carpenter’s pencil and simply went to town on the right wing and strake tops (pic 1).  I then grabbed my stick o’ pain and started work from the leading edge aft on the right wing (pic 2).  I was a bit surprised at how many low spots I had, but that is the entire reason for using a guide coat in the first place, eh?

After a number of rounds of using the long sanding block, and then the 30″ boat-sanding block (with 4.5″ wide 3M Stikit 36 grit paper), I stopped when the wing’s micro surface was close to final level… I’d say over 90% final.

I then installed the aileron on the wing and the rudder on the winglet.

I spent the rest of the evening and most of today working to fine-tune and dial-in the intersecting seams of the aileron to wing and rudder to winglet.

Part of the effort on finalizing the right aileron finishing and install was mounting a clickbond in the middle of outboard hinge, in between the 2 existing screws.  I 3D printed a sanding block and prepped the clickbond for bonding.

Here’s a shot of the clickbond floxed in place and secured with a ply of BID and a ply of UNI (after cure).

I shot a video detailing what exactly I’m up to with adding this clickbond to the right aileron’s outboard hinge.  It also includes a project update at the current state of the build.

Tomorrow I’ll continue to press forward with sanding the micro-finish on the wings, strakes and winglets in my quest to get them finished and ready for paint.

Again, my current status is that I have both wings, both winglets, both strakes, both rudders, and both ailerons now in micro [caveat: underside outboard few feet of wing and inside lower winglets currently not micro’d].

My next task that I didn’t grab a shot of was prepping and microing the top surface of the left aileron.

As you might have guessed, I’m trying to keep the micro cure times somewhat matched for the control surfaces: inboard rudder to inboard winglet; top of aileron to top of wing, etc. to match sand those surfaces here shortly.

I bought some 40 grit sanding disks for my orbital sander and did a full regime of that on the right wing and strake tops.  I also hit both sides of the right winglet, the winglet-to-wing fairing and around the wingtip area at the Nav/Strobe light bump.

I then did a few more rounds on the right side with my air file, which really got the micro knocked down to much closer to final contour… I’d say about 80% done.  Tomorrow I’ll probably do one final round with the air file before switching to hand sanding with what my buddy Dave B. calls “the sticks of pain,” AKA sanding boards.

As with so many things on this build, the micro-finishing work is an iterative process. It’s certainly a workout, and can be monotonous and repetitive, but it really is a cool process to see the imperfect surfaces get so smoothed out.  I have to say I’m really pleased so far as to how it’s all shaping up.

Here we have the right wing tip Nav/Strobe base, also at about 80% to final.

I then got to work on the left side, mainly just get the high spots knocked down and the micro to general shape.  I hit the entire micro’d surfaces of the left wing and strake, and also leading edge on both of those as well.  I still have quite a bit to go on the left side, but it was a good start.

I’m at the point on the right side where I’ll be breaking out my pencil (or black paint) to ensure my surface level is even across the board as I finalize my micro application.

Moving forward.

This blog post covers the past two days, since I’m just now getting to posting it.

First off, since I was up pretty darn late microing up the left strake top and leading edge, it was mid-afternoon when I got around to cheese grating the surface to knock down the high spots.  This took nearly 2 hours.

I then needed to run out and knock out a few errands, and upon my return mid-evening I spent another good 2 hours prepping the left wing and inboard winglet for micro.

I taped up the wing-strake seam gap and also mounted the top cowling, with its interfacing edge taped up.  And I finally remembered to get a shot of the extended/ relocated strake flange edge over to the wing… eliminating an air gap along the front outboard edge of the top strake.  You can see the difference from before (pic 1) and after (pic 2).

Here’s a shot of the cleaned and prepped left wing top and inboard left winglet, ready for micro.

Today I got busy with my left wing/inboard winglet micro task by first apply flocro around the wing-strake seam edge, as I have on all my other micro finishing jobs.

And again, over 4 hours later here we have the left wing top, leading edge and inboard winglet surfaces micro’d.

Another shot of the left wing top micro’d up.

And one final shot of left wing top and inboard winglet micro’d.

Tomorrow I plan on applying micro to the top of the left aileron and cheese grating the micro I just applied on the left wing tonight.  In addition, I plan to start sanding the right wing, inboard winglet and strake.

Today I continued on in my micro finishing fury by knocking out the microing of the left strake.

But first I spent a good hour+ cheese grating the just-micro’d right strake.

I needed to get some prerequisite tasks completed before I could get to microing up the left strake.  First on the list was to recut the aft strake-to-wing junction 1 ply BID layup that I did a couple of days ago.

I taped a metal “yardstick” in place as a straight line cutting guide (pic 1) and then made the cut (pic 2).

While I was right there in the immediate area with my ‘Fein’ saw in hand, I also cut the flange reallocation layup that I did where I moved a piece of the strake flange over to the wing [I had meant to get a closeup pic of this now non-gap when I put the top cowl on during the left strake micro finishing… but forgot].

I then pulled my air file out of its semi-retirement, knocked off the dust and put some tool oil in it.  I spent a good 15 minutes (what a workout!) knocking down a good bit of the micro on the outboard side of the left winglet.  The majority of the finishing on this area from here on out will be hand sanding with sanding blocks.

I then did the same thing on the outboard side of the right winglet.  Again, because the workshop wall is so close to this winglet, I needed 2 pics to get a shot of the entire winglet.  Also, the same holds true here as on the left side, where I’ll be using mainly hand sanding blocks to finish the contouring of the winglet.

I received two separate phone calls from my son and my daughter, so I was on the phone a good bit… since airplane building has kept me quite occupied lately.  Thus, although it was getting later into the evening, I wanted to get micro laid down on the left strake top.  I prepped the strake top, cleaned it up and then taped the seam edge with the wing.

Again, I started off by whipping up flocro and putting a bead around the strake-wing seam edge.

And a few hours later I had completed my task of microing up the left strake top and leading edge.  I also added some micro I had left over to the fuselage wall just forward of the strake junction with the fuselage.  Note that the strake-to-wing seam edge tape has been pulled.

Here’s another angle of the left strake in micro… no more crazy multi-colored strakes from this point on.  Kinda weird to see in a way!

Here we have a closer shot of the junction between strake and wing, with the gap tape pulled and the razor knife run through it multiple times to clean it up.

It was very late (or technically very early morning), but I wanted to get another round of micro in on a large component to allow me to rest my shoulder and back with some sleep before tackling the left wing top, leading edge and inboard winglet… which is next on the docket.

Getting there… one bowl of micro at a time!

The micro finishing sword that is…  ha!

Today was nearly all about getting the right strake top and leading edge slathered up in micro.  I did take the ailerons outside and sand the bottom of those a good bit with the orbital sander as well as the outboard side of the rudders… I had to get to that micro knocked down some before it got too hard to work with.  I still seriously need to sand the outboard side of the winglets, but keep getting distracted with laying down more micro while the days are warm.

But the very first thing I did this morning early was to spend a couple of hours cheese-grating the inboard right winglet and right wing top micro.

I then cleaned and prepped the right strake top and leading edge for micro, taping off the seam with the wing and also the top cowling, which I remounted for this task.

As I did on the wing, I laid in a narrow line of flocro on the edge of the right strake seam with the wing, to harden up the edge a bit for wing installation and removal ops.

I then spent the next few hours slathering up the right strake top and leading edge with micro.

I had a good bit of micro left over from my last batch, and not wanting to waste it I simply slathered up the fuselage forward of the strake, underneath the canard and a bit on the nose as well.

Here we have the right strake and some of the forward fuselage micro’d up. Obviously I still have the canopy in place, so I didn’t do all of the longerons or turtledeck… that will come later.

After all the micro was applied, I then went through and pulled the thick Gorilla duct tape from the strake-to-wing seam.  I ran a razor knife down the seam to clean it up a bit, and will sand it clean when I remove the wing, but I do have a nice, narrow distinct seam line between the two.

And here’s my final parting shot of the evening, with the right winglet, wing and now strake all in micro.

Tomorrow I do plan on paying the piper in sanding the outboard winglets (and hopefully right wing as well), but do plan on prepping and getting the majority of the left strake top micro’d up as well… but no fuselage micro at this point on the left side since I need to do some canopy interface work on the forward longeron and fuselage.

Pressing forward with finishing!

Today was all about getting the top of the right wing and the inboard side of the right winglet micro’d up.

I started by cutting my new conjoined strake flange and wing edge to once again make two separate flanges.  As you can see I have eliminated two problems in doing this little step:

First, I’ve eliminated an engine compartment air escape gap, and second —and honestly perhaps more importantly!— I removed a very unsightly gap between wing and top cowl edge.

I had planned on doing a bunch of component micro sanding first, but I didn’t want to push my luck as far as time.  And boy oh boy did I make the right call… this was a beast!

After final sanding, vacuuming and cleaning, I then taped up the edges around the inboard side of the wing.

I mixed some thick flocro up and created an edge around the strake interface gap, to harden this edge during wing removal and installation.  Off on the far end you can see I started micro’ing up the inboard winglet.

The first pic is exactly an hour into my wing micro task, while pic 2 is 2 hours in (no kidding!).

Here we have the entire right wing top and inboard winglet in micro… all in all it took me nearly 7 hours (yep, not lying!) to micro this beast up.  Clearly there was no dilly-dallying going on either.

And one more shot of the completed micro on the right wing top and inboard winglet.

Tomorrow I plan to seriously get to sanding the inboard sides of my rudders, the bottom sides of the ailerons, and the outboard sides of the winglets.  I also plan on microing up the top of the right strake, and the top of the right aileron as well.

Since I knew I was going to make some dust —of the worst kind (carbon fiber)— I started off this morning by taping up the canopy’s protective plastic cover to ensure no plexiglass was exposed.  I also taped up the majority of the seams between canopy and airframe.

The layups I did last week on the inside front lip of the top cowling come into play here. And solves an issue that has been high on my list of things that were gnawing at me, since I saw it every time the top cowl was mounted in place: what I dubbed “10&2” on my lists (clock positions)… in homage to my high school driver’s education teacher always yelling at us that was the proper hand position when driving.

Looking from aft of the cowling, the less egregious was the 10 O’clock position shown below (pic 1) where it has a considerably higher elevation than the interfacing D-deck surface.  I put the shop vac nozzle close by as I used the Dremel tool, belt sander, orbital sander, and then hand sanded down this protrusion to an acceptable level (pic 1).  I could do this without cutting through the originally cowling with the extra plies on the INSIDE of the cowling to fill that gap, so in reality the layup and this cowl edge removal action is just that: a twofer!

At the 2 O’clock position it was the same story, albeit even worse.  I laid up 3 extra plies on this side, inside, again to not only back fill the air gap that was present from this extreme case of “oil canning,” (pic 1) but provide carbon fiber on the inside to allow me to grind down and remove the cowling’s original top surface (pic 2).  Since I’ll be painting the top cowling, these 10&2 areas will be hidden by micro and paint.  Yet another very fulfilling task complete!

Since I had my orbital sander and shop vac plugged in and at the ready, as well as my canopy covered and seams taped closed, I took the opportunity to do a good final sanding of the right strake’s top surface in prep for upcoming micro.

Another prerequisite task that needed to be completed before the actual microing up of the wings is the air gap on the outside front corner of top cowling, where it meets the wing.  I had an aha moment the other day as I was pondering how exactly I was going to do this, since it would be easier with the wings off, but I don’t want to spend the sheer time and effort to remove the wings and remount them just for this.  And clearly the wings need to be on during the finishing process to get them all even-steven and matched surface-wise with the strakes.

Here is the offending gap on the left (pic 1) and on the right (pic 2).
[In pic 1 note the crack in the wing flange at the corner about 1.5″ above the tip of the scribe… I discuss this in my next layup]

My eveel ingenious (that’s what I’m calling it… just go with it!) plan entailed simply floxing and glassing the strake’s cowl flange to the wing’s inside edge in situ, to then be cut after cure. To be clear, my plan involved layups on both the inside (underneath) and the topside, as I did in the pics below, but the wing is way thicker than the flange, so I’ll need to have good eyes-on and full access to work that… this should suffice for now:  some flox in the gap and a ply of BID, peel plied of course.

To keep my topics straight, I’m jumping ahead in time with the layups cured, and peel ply pulled.  Here we have my cut lines marked, which I will cut tomorrow after a good overnight cure.

Another layup task I completed in prep for finishing both the left wing and strake had a twofold purpose:  1) there was about an inch long crack on the wing-side flange at the very outboard edge/corner near the intersection of strake, top cowl and wing (closeup in pic above), and 2) when I set the wings in final position, the extra washers I placed on the left side wing bolts created a wider strake-wing intersection gap than the right side, and more than what I preferred.

So I laid up a single ply of BID, 1.5″ wide down the length and across the aft strake to wing intersection gap.  This will allow me to cover and reinforce the cracked wing flange while also reestablishing a thin gap “kerf” between strake and wing, since I still have to do the backside (underside) reinforcement layups on both strake and wing intersection lips after wing removal.

Again, jumping ahead hours later this is after cure when I pulled the peel ply (I will recut the left strake-to-wing intersection gap line tomorrow).

My final layup task for the day, again in prep for slathering up the left wing and winglet with micro, was to repair a small divot at the very top aft inboard edge of the left winglet.

This was simply a very thin area of UNI that somewhat aggressive sanding in prep for micro exposed.  You can see the spot where I cut away the dry, thin delam’d UNI where the light spot is from me reapplying micro, adding a very small patch of BID in the bare foam hole, then covering it with a ply of UNI.

On the aft 1/2″ TE depression I also added a postage stamp sized piece of BID both for transition at the depression for the overlying UNI (pic 1), but also to reinforce the aft top corner, which looked a bit rounded compared to its counterpart on the right wing.  Which all can be seen after I pulled the peel ply and razor trimmed the glass (pic 2).

Yes, it was quite a long, busy day… I pulled the bottom cowling off to allow me to get the wing root heat shields out to subsequently get the ailerons pulled off the wings [this pic also has the right wing top and inboard winglet final sanded and prepped for micro… which was my last task of the evening].

I then micro’d up the bottom surfaces of the ailerons.  Not shown is a pic where many hours later I cheese grated the micro-laden ailerons.

If you’re wondering why the right aileron (left in pic) is not fully covered in micro, it’s because when I skinned the bottom of the right wing many moons ago I followed some bad advice and immediately added some micro to the curing wing bottom skin.  Thus I have a layer of micro that has already been sanded down and the middle area is fine.  Just the overlapping BID on the forward edge and the trailing edge really needed it.

Also not shown was my using the orbital sanding to knock down the micro on the inboard side of the rudders about 80% to final.  Time was getting away from me and I wanted to knock down the micro before it got too hard to “comfortably” sand, which honestly will be job #1 tomorrow when I get into the shop (sanding micro’d surfaces).  Unfortunately it was very late, dark, and cold outside, so I sanded the rudders inside… yep, I broke the seal on getting dust everywhere!  Thankfully the plastic sheets are containing it in large measure so that only everything inside the plastic walls is covered in micro dust (sheesh).

My major goal for tomorrow is to micro up the right wing top and inboard winglet.

Moving forward…

While I did do some more assessing and part mockups for the canopy latching hardware (more on that in the next day or two), my primary effort today was micro-finishing the outboard winglets.

I first got the left winglet prepped for micro, doing a good final sanding of any previous spots missed and then cleaning it for good micro adhesion.

I then whipped up and slathered on my micro/West 410 mix.  It took 12 pumps worth of West epoxy/hardener to cover the outboard left winglet.

As the left side outboard winglet micro cured, I then set my sights on the right outboard winglet and prepped it for final micro application as I had done on the left.  I have to split the pics between upper and lower since I can’t back up any farther to get these shots: my hand with the camera is up against the wall.

I then slathered on the micro on the outboard right winglet.  I used the same 12 pumps here, but I seemed to have slathered a little bit more towards the top (where I started) so I didn’t have quite the coverage on the lower side.  All good since I clearly have to add more micro on the inboard side of the winglet.

By this point the micro on the outboard left winglet had cured to its “green” stage and was ready for cheese-grating, which I spent a good 20 minutes knocking down all the higher ridges and higher areas.

I really do think this relatively short task is the trick to significantly lowering the time required for sanding after the micro fully cures (24-48 hours) in that you avoid wasting time sanding down the ridges and high spots and start at a much closer level to the final contour.

A few hours later I did the same on the outboard right winglet, with its micro application cured to its “green” stage, I cheese-grated it as well.  Although admittedly it was not as cured as I would have liked, and all the cheese-grating went fine, it was just a tad softer than I normally like it to be so it made removing the more-gummy shavings out of the cheese-grater a bit more of a time-consuming process.  However, it was quite late and I wanted to get the surface cheese grated prior to it curing to a much harder state.

And with that, I called it a night.

Over the next week I’ll be juggling between applying micro on different segments of the bird, cheese-grating and final sanding of these parts.  Later on after nearly all the parts are final sanded and cured, I’ll get to the epoxy wiping.

Pressing forward!

Today I was still embroiled in a lot of planning and assessing my path forward on various components on this bird that need some fairly expedited attention.

That being said, I also needed to get on with getting the micro finish (when I say that, I almost always mean about 4-5 part micro balloons plus a single part West 410 filler.  As our RV brethren have discovered, this makes sanding the micro finish infinitely easier with no noticeable loss in surface hardness) on this bird, so I slathered up the inside surfaces of the removed rudders with micro (pic 1) and then between 4-5 hours later I gave them a good working over with the cheese grater (pic 2).

During the cure time of the micro above I did some trial fits and ops test of my newly designed C4 canopy rod connector.  I trimmed down the inboard portion by 1/16″, but then ended up adding 0.02″ thickness back to it for the final version.  I plan on machining this fairly soon out of aluminum stock.

A bit later I prepped the outboard surfaces of the rudders for micro, including taping up the hinges and hidden bellhorn arms.

I also fired up my heat lamp and set a bondo knife on the 4 sides of the protective wire cage, one against each wire.  This is my method for always having a piping hot applicator that really helps “melt” the micro and make it WAY easier to apply to the glass surface.  I’ll use one for a minute or two max, then wipe it off, set it back on the heatlamp before grabbing the next one and using it for just a bit before the heat dissipates, then on to the next one.  Again, the heat is super, super critical in my opinion for getting a good flow of the micro onto the part.

I then slathered up the outboard sides of the rudders with micro.

Again, I took the cheese grater to the outboard micro on the rudders a few hours later.  At this stage it makes the micro look like either shredded coconut or mozzarella cheese.

And here’s the result.  I realize it’s a bit hard to tell with the distance of the camera and the white surface, but the high ridges are all knocked down and these will be ready for final sanding in the next day or two (at most).

Tomorrow I plan on continuing on with my micro-finishing of various parts, with the outboard winglets and ailerons on the short list of candidates.

Pressing forward!