Chapter 24 – Lower fuselage/hell hole

I started this morning by filling in the very aft area of the lower fuselage with pour foam, obviously inside the dams/forms I created last night.

A little while later I pulled off the forms.

Here are a couple side shots of the applied pour foam up to this point.

And a look at it from the aft firewall.

I then used a hacksaw blade and my “cheese grater” to knock down big pile of cured pour foam.

I then set up a form to fill in the area under (“over” when inverted) the right gear leg.  In addition, in this inverted state I set up a “floor” to in turn create a section of the bottom floor of the hell hole. Moreover, I set up the thickness so that once the foam cures it’s at the appropriate height to glass almost immediately with only minor tweaking.

Here’s another shot of the form for the right hand “corner” of the exterior hell hole floor/wall.

And a couple external shots of that form configuration as well,

And here is all that with the pour foam in action.

After the pour foam cured, I then removed the forms and knocked down the excess foam.

I then dialed in the surface level of this freshly added foam with my sanding block.

I cleaned up the inside, removed excess foam and sanded the surface to rough it up a bit from the smooth glossy surface it gets from curing against duct tape.  I also ensured all the transitions between foam and existing fuselage structure was even and worthy of glass.

After micro’ing up the foam I then laid up a ply of BID, in 3 pieces, that overlapped onto the lower longeron, firewall and aft fuselage edge. I then peel plied the inboard (nearest the opening) edge with 3″ wide peel ply tape.

This was definitely a challenging layup primarily due to the lack of access I had to the areas where I was laying up the glass.  I used the bigger stir sticks as a squeegee in the corners and to ensure the glass was attached to the foam with as few bubbles and air gaps as possible.

I then left this layup to cure overnight.


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