Glasair Overhead GPS Antenna Tray

Here are a couple of quick drawings for my overhead GPS antenna tray.

1. Produce side walls from 1/4 inch foam, coat one side with Q-cell and a 2 layer laminate. This will be the inside. Bond the walls together with Q-cell mixture. Lay saran wrap down and bond together inside the fuselage (inverted) if possible to assure perfect fit. Use Q-cell and a 2 layer laminate to fix the corners.
2. Lay down saran wrap and peel ply on a work table, and make a flange at the bottom of the structure. Cut off about 3/4″ diagonally at the corners and use a sheet metal brake to bend a flange outside the edges of the fiberglass structure.
3. Coat the outside of the walls with Q-cell and a 2 layer laminate.
4. Obtain a piece of sheet aluminum (.020 to .032) and mark 1/4″ outside the size of the bottom of the structure. Cut off about 3/4″ diagonally at the corners and use a sheet metal brake to bend a flange outside the edges of the fiberglass structure.
5. Drill the metal bottom in six places about 1/2″ inside the bend lines for screws and use the bottom as a drilling guide to drill through the fiberglass flange on the bottom of the structure. Install nut plates on the flange using countersunk rivets and standard technique.
6. Remove the metal bottom and bond the structure into place in the fuselage using standard Q-cell radius and edge laminate technique.

This clearly would be much more difficult with the fuselage upright, so I installed this prior to installation of the tail.