Boot cowl progress

Well, I had some distractions last week and Cub progress ground to a halt. This week the weather is forecast to be clear with seasonable temps so I'm back at work. With the fuselage outside I have room to work on the boot cowling. Today I fitted the nut plates for the 10 windshield screws that are blocked from access by the fuel tank. Since I did not have a drill jig for this size nut plate I had to make one from a piece of scrap aluminum. I really needed this jig to help stabilize the the pilot of the counter sink to prevent it from "chattering". It all worked great and I will rivet these on tomorrow. This shot shows the location of the screw holes.

I plan to use tinnerman nuts on the center seam held by clecos in this shot. This area is non-structural and that is much easier than riveting on nut plates. The remaining windshield screws can be accessed from under the instrument panel. This shot shows the drill jig I made for the floating nutplates.

These came reasonably nice as shown in this shot.

I then set out to fix the incorrectly drilled holes in the side of the cowl. I decided to attempt to fill these with counter sunk 3/32 rivets and just a little filler if needed. Since the holes were much larger than 3/32 I had to make some sub structure to stabilize the rivets during installation. I made 4 strips of 0.032 aluminum 1 inch wide to install behind the holes. This shot shows these strips installed .

These strips drilled #40 allowed me to anchor the pilot of the counter sink and dress the existing holes for rivets.  Here is a shot of one double drilled location ready for riveting.

 Here it is with the rivets installed. This is about the best that could be expected considering how bad this was butchered by Coastal Aviation.

The firewall location where the gascolator is installed was another challenge . I had to properly locate the mounting holes and repair the miss drilled holes. I started by making a patch to be installed on the outside which will cover the extra holes. This shot shows the patch I made , it will be installed with rivets around the edge and also held with the gascolator attach screws.

Here it is with the gascolator and mounting bracket installed.

Here is a shot of the Coastal Aviation butcher job I had to cover.

I also finished the installation of the cabin heat air box. Tomorrow I will prime a few areas and finish riveting all these repairs and install the nut plates. I will fit this to the fuselage one more time to drill the final mounting holes (hopefully) in the correct locations. If all goes well I will have the final paint on this part this week.