I've long admired the work of the many racing craftsman I've been associated with over the years, and so I naively set off to replace a broken trim piece and its concertina-wire-like vent. Sure, I could have simply mended the broken pieces, painted the part, and reinstalled it on our beloved 1968 Bonanza 36, but with thoughts of carbon fiber pieces dancing in my head, I traveled down the path of no return. Sure, carbon fiber wasn't even a gleam in the eyes of the Beechcraft designers way back then, but hey, nothing like introducing a little modern material to a classic aircraft.

So here are a few "before" shots of the front and back of the broken trim piece:




Drawing up the template:


Part weight, and a good look at the nasty edges on the metal vent screen:


Template overlaid on the fiberboard that will act as the mold for the carbon fiber layup:


I don't have a table saw, so it's a straight edge (bubble level) and some clamps to hold the line as desired:


Here I'm using the family's 40+ year-old radial arm saw for the end cut:


Cutting the plywood base on which the fiberboard mold will be mounted:


A quick trip to the belt sander to radius the mold's edges:


For the smaller door latch guard, it's a bit of free forming with the jigsaw:


The door latch guard ramps up where it's fastened, so here I'm checking the mold piece I've cut to ensure it matches the original piece's slope:


The ramps:


The original piece and the new mold:


The simple (in comparison) fiber board mold for the larger vent piece:


$65-a- yard carbon fiber... ugh....:


Here's the larger mold, mounted, waxed, and ready for the carbon fiber:


I used the West Marine epoxy system for the resin and hardener... good stuff:


I laid up 3 layers of carbon fiber on the first go... I'm embarrassed looking at this photo that I didn't trim the pieces better, but I figured I'd clean up the part afterward:


Peel ply going down first on top of the carbon mat:


Pre-preg sheet and absorbing cloth:


Everything sealed up with the vacuum pump running:


Although it's a brisk 55 degrees in my little workshop, almost immediately the temperature is rising on the part due to the chemical reaction that's occurring with the resin and hardener:


12 hours later, the bag is opened and here's what I found:


It just needs a bit of trimming and a little "ventilation:"


Using EXCEL, I laid out a pattern of "X"s and then printed it out an 11"x14" piece of paper. Here I've attached the paper to the part after trimming:


Drilling the holes on the drill press:


Back to the door latch... mold waxed and ready for the carbon mat:


The door latch mold with wetted mat ready for its 12 hours of vacuum bagging:


The original piece, the mold, and the resulting carbon fiber part:


And here's the final vent piece being installed:


Well, as usual with something like this, I learned a ton and was quietly reminded that the craftsmen I worked alongside during my sports car and IndyCar days, were really talented. I hope you enjoyed riding along with me as I learned a little bit about vacuum bagging and forming carbon fiber parts.