Chapter 4 - Bulkheads, Instrument Panel, Front Seatback and Temporary Firewall

Chapter 4 starts off fairly simple - you’re working entirely with flat shapes that are all internal to the aircraft. The only curves are the edges.

Current status (Late May, 2022): In early May 2022, I had a minisplit installed in my workshop. Since then, I have done at least an hour of work a day in the workshop. Work is thus proceeding at a brisk pace, and I hope to complete chapter 4 by mid June.

Front Seatback

The front seatback is very simple - cut down a slab of 0.75“ thick foam, shape two of the edges to be 45°, and glass it. Following the advice of other builders, I used a tablesaw to make those cuts. You can see the result below.

Angle shot of the entire foam slab prior to glassing Closeup of the 45 degree edge on the foam slab prior to glassing

A few days later, I did the next step, which is to add micro and UNI fiberglass to one side. I interpreted “micro” in this case to be wet micro, not micro slurry. We’ll see how it turns out.

I cut out 2 lengths (approximately 42-45 inches) of full-width UNI and laid them out. I had to cut and rearrange the glass while laying it out, and there was some excess, but this worked well. Instead of using the polyester sheet as peel ply, like I had previously, I used plastic sheeting. We’ll see how it turns out.

Angle shot of the front seatback after the first side is glassed

It turned out fine. I did go back to using polyester peel ply for the aft side of the front seatback. Which also turned out fine and was relatively easy to pull out.

I identified a number of inconsistencies in the epoxy cure on both sides, and will be drilling holes and injecting epoxy into them once it warms up and I’m sure the injected epoxy will correctly cure.

F-28 Bulkhead

The F-28 Bulkhead is a relatively small piece, and will be made of fiberglass glassed onto clark foam. I cut the foam out using a utility knife and a Fein tool.

Currently, I have the F-28 bulkhead cut, but have not glassed it.

F-22 Bulkhead

The F-28 Bulkhead is the first piece that I need to build in pieces, then epoxy together. Similar to the F-28 bulkhead, I cut this out of clark foam using a utility knife and a Fein tool, and then sanding for a more precise finish.

On Sunday, 2022-05-22, I glassed the aft face of the F-22 bulkhead, including adding the doubler. Once it cures, I’ll take a look at it and finish it.

Instrument Panel

The Instrument Panel is roughly the same size as the F-22 bulkhead. It’s current state is also foam pieces, epoxied together with 5-minute epoxy. Along with the other bulkheads, I have not yet glassed it.

Additionally, I need to cut out and prepare the stiffeners and cable channels for the instrument panel. Which, per plans, I’ll do after glassing both sides.

The instrument Panel (and F-28) are both next in line for glassing, to be done the week of 2022-05-23, probably on the same day.

Landing Gear Bulkheads

Along with the other bulkheads, the landing gear bulkheads have had their foam parts cut out and epoxied together with 5-minute epoxy.

I have laid up all 4 of the fiberglass hardpoints, all of which have come out quite well. I need to cut them to their desired shapes, and then ultimately add them to the foam bulkheads when I glass them.

Firewall

I have built a temporary firewall, and I have also cut out parts of the permanent firewall. I need to cut out the remaining pieces of the permanent firewall, as well as glass them. I have alodyne on order from Aircraft spruce. I’ll use that to protect the aluminum parts prior to inserting them into the firewall. Once the alodyne arrives, I’ll complete work on the firewall.

Last updated: 2022-05-23 19:39:24 -0700