Today I got yet another task that’s long been on my list to do finally knocked out: the top cowl aft reinforcement stiffener.  Technically this is my second attempt at this, since the first reinforcement strip didn’t do I what I needed it to (which I had honestly kind of forgotten about since I set my mind on doing this new and improved version)… which with the spring back of the top cowling may be too much to ask for, but I want to try to maintain at least a 5/16″ gap between cowl and prop spinner flow guide.  It’d be a shame not to be able to use the prop spinner due to a lack of proper clearance.

Here’s another shot of my starting point, with the pour foam in place and completed last night.

I then got to work shaping the pour foam and knocking it down to about 3/8″ max height in the center, with each side beveled down to meet the cowl surface.

Here we have the final foam base of the top cowl aft cross stiffener shaped and vacuumed, ready for glass/carbon fiber, which you can see I’ve cut and is above the foam, awaiting layup.

Using Hi-temp HTR-212 resin, I then wet out the foam with micro (pic 1) before laying up the 2 plies of UNI (pic 2).

I added a strip of Lantor Soric material next (not seen), then 2 plies of carbon fiber just a bit wider than the all the rest of the plies, to secure the whole shmeal to the top cowl surface.

I then added peel ply, mainly focusing on the edge interfaces between carbon fiber plies and top cowl.

I installed the top cowl with all the CAMLOCs in place (no screw on each side) so that the top cowl would be in its final configuration during the aft cross stiffener cure.  You can see that I prepped the flow guide by hot gluing wood spacers to the surface and also clamping it to the flywheel to ensure that it’s secure during the ensuing 48 hour cure/post cure.

I then added a heat blanket on top of the cowling, just over the aft cross stiffener layup, and put a couple heat lamps underneath.  I then left it to cure… again, I’m planning on a good 48 cure to hopefully lock this top cowl position into place.

I’ll note that over the last couple of days I finally broke out the cheap toaster oven I bought late last year to allow me to heat up the wing leading edge 1/16″ plexiglass lens plates, that I bought from ACS pre-cut at 8″ x 8″ (on top of oven).

Late last year Nick Ugolini sent me his plaster of paris molds for the wing leading edge lights.  He also sent me nearly 100 pics and we had a long detailed conversation on how to create the embedded wing leading edge lights.

After looking over my personal notes, my notes on the call with Nick and some Internet research/videos, I got to work making some lenses.  The lens on the far left (below) is one that Nick sent with the forms.  The #3 smaller 5″ x 8″ lens is actually the second one I tried, the 3″ strip that I had cut off with the Fein saw being the first test piece.  It came out clear as well, and the smaller one came out pretty good too… but it wasn’t centered perfectly so it might not work for an actual final lens.

Since the corners tend to curl up a bit, I decided to leave the lenses at the 8″ x 8″ dimension that I got them from ACS.  I tried to let it heat just about 30 seconds longer to see if I could get the corners to lay down better, and lens #4 on the far right is what I got… air bubbles in the final outcome.  30 seconds less heating time and slightly curved corners is what I got on my final attempt for this go around, lens #2, second from left.

I then discovered one more final issue that really drove a decision point for me.  Although I had each lens perfectly conformed to the lens mold that Nick sent me, I noticed that the mold is significantly fatter on the bottom curve than my wing (by about 0.2″).  Nick had also sent me a piece of a wing leading edge that was cut out for making the lens light pocket, and it didn’t match my resulting lenses from the mold either.  It actually matched pretty darn close to my wing (which I would guess it should).  Hmmm?

Since the lens configuration and shape drives the exact position of the light on the leading edge, I realized that I was going to have to create the lenses in situ on each wing.  And since the top of my wings are not yet finished, I then subsequently made the call to re-sequence this task until after the wings are micro finished, epoxy wiped and sanded to final shape (but pre-paint).

Inching forward!