Although not quite as hot as yesterday, today was still darn hot. With activities limited to indoors (by me!), today was all about getting the topside winglet intersection fairings glassed.
Of course this meant first that I had to foam and shape the left side fairing.
As I did on the strakes, I simply cleaned up and flipped the tape-covered-cardboard dams that I used on the right side to pour the left winglet intersection fairing foam.
Note that as I did on the right fairing, I have the cardboard dam sitting on the edge of the fairing to keep a good 1/4-3/8″ bare edge (no foam) for ensuring a glass-to-glass seam along this fairing “TE.”
After getting the dam in place I then mixed up and slathered in 2 batches of the pour foam.
After the foam cured, I then started by trimming off the top with the wood saw before I then removed the dam.
A bit more major foam removal with the wood saw.
And then the first couple of rounds with the 2.8″ diameter fire extinguisher mounting “cup” (that I’m not using now) with 50 grit sandpaper wrapped around it.
After a few more rounds, including some smaller diameter Perma-Grit tools, I finally had a pleasing shape for my fairing. I also tweaked the right side contour just a hair as well.
It was now time for glass.
First I want to share with you what I read recently on the COBA canard forums, where a guy mentioned that every pound he added aft of the firewall meant he needed 1/2 a pound of ballast in the nose. I don’t know how specifically accurate that is but lately, between his comment and Klaus’s admonishment on build weight, I’m re-motivated and have been on a “diet” with the bird in regards to weight management (if only I myself could be so disciplined!).
I mention this to say obviously that I want to add as little weight as possible on these fairings. Thus on the front half of the first ply I decided to use UNI vs BID simply because it’s a bit lighter.
On the aft side for the first ply I chose BID because I want to reinforce the “wall” that makes up the aft 1/3 of the outboard vertical component of the fairing… immediately adjacent to the rudder. I also overlapped this aft BID a good inch forward of the front vertical edge of the rudder so that it would be secured to the actual winglet.
This ply of BID also overlaps just a bit onto the UNI.
Ply #2 is simply a single piece of BID that covers the previous plies and of course the entire topside winglet intersection faring.
After adding micro/slurry to the foam and wetting out the surrounding glass edges, I first laid up the forward ply of UNI, then the aft ply of BID.
These steps are representative of what I did on the right side as well.
I then laid up the top ply of BID and wetted it out.
And then peel plied the entire layup.
Again, I did the same thing on the right side.
I’m very happy with how these winglet intersection fairings turned out… I think they look pretty darn snazzy and the weight penalty isn’t bad either. I’ll gauge the rigidity of fairing, but my initial thought right now is that I’m only going to use a single ply of BID on the bottom of the fairing over the intersection foam. I’ll confirm that after these layups cure overnight.
Tomorrow is supposed to be another hot day, and I’m simply not going to cover up and wear a mask, etc. to sand down carbon fiber on a hot day. Moreover, since I’ve been hard at work on the plane build for weeks solid now, it’s time to take my girl out on the boat for a nice day on the water. In short, not a lot of plane-building is going to get done tomorrow.