- cut 2 layers of BID fiberglass on the bias, ready for pre-preg; retaped the perimeter of the fairing, readying for sanding tomorrow (after filler fully cures)
- sanded the epoxy/microballoon paste, applied second layer of tinted BID fiberglass cut on bias, pre-preg
- sanded fiberglass (80 grit); wiped with IPA; replaced black tape; applied skim layer of Aeropoxy Light (s.g. of 0.49!)
- sanded Aeropoxy Light (80 grit), re-applied Aeropoxy light in several slightly low areas, to try to get the transition close to perfect side-to-side
- sanded Aeropoxy light, sprayed with filler primer (SEM), and did 4 rounds of filling with “Icing” (like Bondo), prior to a final coat of primer. Looks beautiful - the canopy fairing was well worth the ~25 hours I spent on it
Re-taped the perimeter with black electrical tape:
Cut two more BID fiberglass (16" x 10") pieces, and sandwiched them between two sheets of visqueen, ready for tinted epoxy pre-preg:
This time I got a picture halfway through cutting the pre-preg, before my hands were too messy to touch the camera. Very easy to cut the strips, if as much of the tinted epoxy has been squeezed to the sized using the bondo spreader:
Pre-preg strips, applied starting from the left toward the right (airplane's sides):
Sanded fiberglass (80 grit) - make sure to get down to the electrical tape, and be careful of the contour:
Warmed Aeropoxy Light on a heating pad, set on high. Store the cans upside down, and start heating them upside down for at least 30min, then turn them right side up, and continue heating until you are ready to use them. The heavier liquid will mostly be on top, and much easier to mix. You'll be surprised at how low the specific gravity is - less than half of pure water! Very light stuff.
Change the black tape, and wipe with isopropyl alcohol:
Mix Aeropoxy light 2:1, and apply with a bondo spreader. Apply slightly thicker than you'll need, and take care to get the contour of the transition area correct. But don't worry - if you don't apply enough, you can apply more later (like I did):
Closeup of the right side. Aeropoxy Light cures in about 8 hrs, but I let it go overnight in a 78F garage:
Sand down to the tape, get your contour correct, and if necessary apply more aeropoxy light. All sanding should be done with a wooden block, not free hand (I should have mentioned that in the last post, too; but, it is evermore important here). Keep the block parallel to the fairing, and sand at approx. a 45deg angle either upward toward the canopy, or downward toward the aluminum. You do NOT want to sand parallel to the fairing, or you'll risk putting grooves in the material. Let second layer of Aeropoxy light cure overnight.
Finish sanding Aeropoxy light with 80 grit, then transition to 120grit and then 220 grit:
Apply a generous amount of filler-primer (I used SEM):
After filler-primer dries (20min), sand with 220grit almost down to the Aeropoxy light, and enough to remove scratches:
The final prep involves using "Icing," which is a bondo-type of polyester resin that cures quickly enough to sand and reapply multiple times in one session. The ratio of hardener to Icing determines the speed at which the material cures. Fast cure = less time waiting to sand, but low work time. Slow cure = more work time, but you'll wait to sand. Experiment with the ratios.
After mixing Icing, skim over pinholes and other defects using a plastic razor blade.
After Icing cures for a few minutes (again, depending on amount of hardener used), gently sand with 220grit. You'll want to sand before it gets too hard, to remove most of the Icing, except for what's left in the pinhole:
Spray filler-primer again, and repeat the process of filling the pinholes until you are satisfied (four iterations for me):
Last pinholes being filled:
Apply final coat of filler-primer, let dry (20min), and peel off all the masking and electrical tape. SEM sprays very evenly, so I didn't need to final sand with 320grit. Voila! A nearly perfect canopy fairing.
Right side:
Yes, FAA, I did this:
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