Bottom Panel Puzzle Joint and More Sanding

I finished up sanding bulkhead #2 and #7 tonight. I am still having a hard time with sanding wood just coated with epoxy. You have to be very careful not to go to bare wood. I think everything will be ok, since most of the spots will be covered with large fillets or cleats that will be added at a later date.
I have been thinking about getting a detailed sander and I think I will pull the trigger soon.

Below are bulkhead #2 and #7 cleaned up. I brought them inside to store them until I am ready to put them together.

Bulkhead #2 

Bulkhead #7

        After I finished up the sanding, I started to work on the bottom panels. I sanded off the individual puzzle fingers and dry fitted them a few times. The puzzle joints are definitely tight to get together, which is what I think the should be. You just have to play with it a little to get it to go together. Once I got it to fit, I mixed up some thickened epoxy with cabosil.  I have it weighted and clamped down.

Bottom Panel #1