This blog is for entertainment purposes only, and is not meant to teach you how to build anything. The author is not responsible for any accident, injury, or loss that occurs as a result of reading this blog. Read this blog at your own risk.

Tuesday, May 26, 2015

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.

No comments:

Post a Comment