Fuselage center section #45 - Lower firewall assembly

Working on the lower firewall shelf and lower corner skins.

Sealed and riveted on the lower firewall shelf.

Installed the sealant fillet between the sides of the center section.

Left side firewall stiffener angle installed.

Had to countersink for these screws that attach the oil tank attach brackets.

Screws, washers and nuts installed.  One pulled rivet gets put in from the aft side of the firewall due to clearance issues.

Right side firewall stiffener angle installed.

Match drilled the lower corner cowl attach plates.

All drilled.

And finally riveted.  The lower three holes get AN470 solid rivets.

Fuselage center section #44 - Lower firewall prep/priming

More work on prepping all the lower firewall/footwell area parts.

Countersinks for nutplates.

Engine mount attach point brackets.  Steel powder coated.

One side of the center section sides gets this forward hole enlarged.

And the other side gets the aft hole enlarged.

I used a compass to draw the hole full size so that I could ensure that the unibit is pushed as needed to keep the hole centered.

All done!

Then the parts were etched, scrubbed and dried for priming.

And primed!

All done!

Started the riveting process.  Pretty basic but for some reason the aft center rivet is a CherryMax.  Its the only one!

This channel gets riveted on with the engine mount bracket.

Then these nutplates get riveted on.

And per the KAI's areas that get sealant and sealant fillets get scuffed up.

The bottom skin gets riveted on in the center along with all these nutplates.

The area between the center section sides gets a sealant fillet.

Fuselage center section #43 - Lower firewall prep

Cutting the firewall/footwell components apart.

Deburring

Lower corner brackets for the cowl attach.

Oil tank mount parts.

Firewall stiffeners.

For the first time I had to make my own tubular bushings from a piece of stock.  The prior ones were pre-made.  All of the ones on the RV-7 were DIY.

Cutting the firewall shelf stiffener channels.  These end up with the rudder pedals bolted to them.

Dimpling per the KAIs.

Dimpling nutplate attach holes.

One of these does not get dimples.

Glad to have the DRDT=2 to dimple these holes.  For some reason some of the firewall holes are pre-dimpled at the factory but they leave a few hard to get to ones for the builder????

Dimpling the ears of these nutplates.

Nutplates installed.

Had to machine countersink all these nutplate attach holes on the lower forward skin.  

Dimpled these holes on the firewall shelf per the KAI's.

And these nutplate attach holes.

This hole gets upsized for a fuel line fitting in the future.  Go slow and check often to push the bit around to keep the hole centered on the factory hole on the firewall shelf.

All done!

Nutplates installed.

Channels installed with nutplates.

All done!