The com antenna plate was not as easy as it looked like and took much more time than I thought.
First step was removing a bit of the skin:
The individual layers (skin, flanges) were not nicely aligned and made it therefore difficult to upsize the holes for the M4 rivnuts. With some 3M 2216 structural epoxy glue I made sure all the layers perfectly aligned:
Also the GPS doubler plate was glued in place to make installation of the middle top skin easier:
After the glue had cured the holes were upsized with a letter A reamer for the M4 rivnuts:
The antenna plate was very close to a hole in the skin which would make it impossible to have the rivet flush:
On the inside the third hole in the stringer did not line up with any hole in the skin:
I redesigned the plate so that the hole in the stringer was used and the other hole covered:
CAM almost ready:
To have a good ground plane for the antenna I removed the earlier sprayed epoxy primer and applied 2 layers of Alodine for corrosion protection:
There was a gap between the skin and stringer:
To fill that gap I designed 2 additional plates:
The main plate was alodined, the support plates primed with epoxy primer:
To prevent moisture entering between the skin and plate a bit of 3M 2216 was used:
The rivnuts were set with 3M 2216 as well. Note: the maximal thickness for the standard rivnuts is 3mm, however due to all the layers one location needed a longer rivnut (3-5.5 mm):
Inside views:
