After taping up the Clickbonds, wire cable and rudder conduits, I started out today by slathering up the mating surface of each Fiberfrax piece with red hi-temp RTV and attaching them to the aft face of the CS spar on each side of the firewall, which I also used a small notched trowel to apply the red RTV.

The left side (pic 1) got a little messier than the right side because I had lot more pieces to fit into place, and with my RTV curing on a seemingly accelerated exponential scale due to the shop temp, I had to get these pieces attached post haste.

Yes, not your typical 70° degree shop temp… nope, today was yet another 100° plus day in the shop.

With the Fiberfrax in place over the exposed CS spar areas, I then cut and applied some Thermo-Tec hi-temp shielding to the shoulder areas on the top side, each side.

With my Thermo-Tec supply out and in-hand, I decided to do a few hour detour on a task that I had not yet fully committed on mentally, but decided it was a GO today: applying Thermo-Tec to the inside face of each inboard wing rib.

In my research/final check on how to apply Fiberfrax to the firewall, etc. not surprisingly I read a few horror stories re. engine fires. I figure anything that adds very little weight yet provides precious minutes or even seconds of flight time in the event of an engine fire is worth getting done.  And now was the time to do it.

So I used painters tape on the inside of the left wing to make up a template.

Which I then removed and took inside my lovely HOT house (AC parts due in tomorrow!).

And imported the template into Fusion 360 CAD.

I then again used my plasma cutting table as a plotter and made a line drawing of my inboard wing rib template on thick paper.

After a few iterations inside the wing, I had refined my left side inside wing rib template configuration.

Which I then used as a pattern to cut out a piece of Thermo-Tec heat shield.

I pulled the backing off the Thermo-Tec to expose the adhesive and carefully fitted it into place.

Here’s another shot of the internal left wing rib vertical wall covered with Thermo-Tec high-temp (up to 2000°) heat shielding.

I then flipped the left side paper template over and made a few minor tweaks to match the right side inside wing rib.

And again used that as a pattern to cut out the Thermo-Tec heat shield…

Which I once again pulled the adhesive backing off and carefully applied it to the inside vertical wall of the right wing rib.

I then spent a good hour getting my plasma cutter and cutting table prepped to cut metal, which I will undertake tomorrow to cut the left and right CS spar “wing” aluminum overlays to protect the Fiberfrax heat shielding.  After the CS spar “wing” heat shields are completed, I will then get to work on the forward wing root heat shields, one per each side.