Nose and nose gear - part 24

Glassing the nose bottom and sides (4.6 hrs)

After one additional dry-micro filling/sanding cycle, I felt comfortable enough about surface smoothness and profile to prep for fiberglassing.

Since I’d be glassing only the bottom half of the forward nose cone, I used duct tape as release agent preventing the BID from attaching to the foam in unwanted areas, and also creating a straight high contrast “cut line” in order to remove the excess fiberglass later.

Duct tape protecting the "no-glass" zone

I really wanted to work on left and right sides separately to make it easier on me, but I decided instead to try to fit the whole nose under one single piece of BID. So, I did both sides at once, even though in the end I didn't quite make it with one piece.

Entire nose slurried

Flox corners filled

Nearly anything goes here, as the manual puts it: “Glass the nose with two plies of BID lapping 1” over SC, the fuselage sides, and bottom. This glassing job is easy if you use several pieces and overlap them… fiber orientation is optional”.

Trying to cover the whole nose in one shot

Laying the second ply (note the considerable unfortunate BID waste)

Both sides needed an additional small triangle of BID to complete coverage

This job is done. Now it's time for the epoxy to go to work.

I sliced the BID over the SC hole, and wrapped it over the SC edges where there was less than 1" overlap.

The dark duck tape "cut-line" is barely visible under the glass

The next morning (2 am), I got up and caught the fiberglass before it got  really hard. I used a razor knife to knife trim all the excess, then went back to bed. I spent the rest of the day trimming and sanding.

Nose finished

Head-on shot

I think she turned out nice

I also reinstalled the nose gear, and made sure there were no new interferences after the latest glassing event.

Cycling gear and speed brake

Nose and nose gear - part 23

Nose cone shaping (12.4 hrs)

The day started out with mostly typical stuff, a little glass cutting, some slurrying, then fiberglassing the inside of the forward nose compartment.

Trying the fit

Glassed and slurried

Finished and cured

With the overnight curing process completed, I flipped the fuselage over and started the much dreaded contouring of the nose bottom. This isn’t a very difficult task at all, but like the nose gracing someone’s face, it will become the only feature people see if it turns out ugly. 

Having Italian sculptors, painters, and architects on both sides of my family, I was hoping to put some of my better genes to good work for once in my life, and pull out anything but an “Italian nose”.

Fast foam removal tool

Sanding the newest foam blocks

Time will tell, meanwhile there were a few things that needed to be fixed. 

Since I had prematurely sanded the bottom foam flush before adding the strut cover, I now had an eighth of an inch step between foam and fiberglass that would not be conducive to smooth lines. So, I cut two small slices of foam and glued them at their intersection, then smoothed the transition with careful sanding.

Outlining the new transition area

Cutting up some thin foam shims

Left foam shim in place

Both shims glued and curing

As you might imagine, very little of the foam slivers remained, just enough to smooth things over. 

Shims mostly sanded down to create a smooth transition

Sanding the nose looked like what you might imagine, proceeding in small increments, then stepping back to take it all in, and judging where to sand next. However, once the rough shape was attained, I employed a technique I made up on the spot, but which proved very effective at achieving round contours that blended across multiple bulkheads.

Using a 36 grit ceramic sandpaper strip that I cut off a belt too wide to fit in the belt sander, I ran it diagonally across the bulkheads to tie the surfaces together…

Working on the cone

Tying the 3 foam zones together

… and perpendicularly to the fuselage centerline to make sure the different stations were round.

Rounding the second zone

Every few strokes of the sandpaper, I would run my bare hands down both sides of the nose feeling for symmetry. It’s amazing how sensitive fingertips are at detecting unwanted sudden curvature changes, and differences left to right. After a while, a decent nose started to emerge from the foam blocks.

General shape sculpted

Even so, a few low spots remained that got filled in with micro then sanded.

Filling all the obvious low spots

Profile view of the fuselage bottom

Though the nose started to look pretty nice, a more careful inspection revealed the low spots to be wider than I had originally assumed.

I'll mix up some micro later and fill these slightly depressed areas

I put the epoxy work off for the day, and pulled out the Dremel tool. I wanted to start prepping a few flox corners for when the nose will get its glass.

Removing foam and dried up micro from the site of the new flox corner

I could have skipped the lower flox corner, but I wanted more adhesion where the bumper will go.

Nose and nose gear - part 22

Strut cover and bottom nose foam installation (9.4 hrs)

One item that I had left unfinished was the foam piece directly in front of the nose gear hinge. In order to have easier access, I should have installed/glassed it before I closed up NG30 with the F6 bulkhead, but it worked out anyway.

Scuffing up fiberglass and dried up micro

Preventing a mess from happening beats having to clean it up anyday

Glassing action

Trimmed a bit long (for now) after cure

At full extension

Because I had split the strut cover (SC) into three pieces, then put it back together with a splice, I was left with a slight depression where the gap used to be, so I filled it out with flox, peel-plied it, cured it and sanded it.

Joint between old and new glass

The depressions were filled with flox and peel plied over

With SC ready for testing, I reinstalled the electric actuator in the nose compartment, and looked for interferences. I found them two. 

Actuator colliding with strut cover

The process for removing them is very straight forward, just sand them until they disappear, but it is very tedious because it involves going back and forth between sanding and fitting many times. That’s what I get for building a plane from plans, instead of buying a perfectly machined airplane kit.

So, I thought I would film the process to give you an idea of what it’s like.

A day in the life

After going back and forth a bunch of times, I was able to achieve a satisfactorily fit, that still minimized air infiltrations.

Interferences removed

The actuator travels unimpeded now

Then I floxed SC in position.

Usual stuff here, a bit of epoxy...

... on all mating surfaces...

... then mix some flox...

... until it's like soft butter...

... then apply it to the joint...

... mate the two parts...

... add some gravity...

... and fast forward 24 hours.

The next day I worked on closing up the last three remaining holes in the bottom of the nose. I cut three foam plugs, microed them them in place, and weighted them down overnight.

Not a perfect fit, but still acceptable.

Another look at the plugs

This level of protection turned out to be an overkill, since there was no sagging of the micro.

Micro applied to foam after slurrying it, and wetting the glassed surfaces with pure epoxy.

Gravity to the rescue once again

Next day