First of all you have to track down the correct hinge material … the manual suggests HINGE PIANO 1/8.
It’s the same, of course, as the hinge used for the cowling sides.
Then trimmed etc as per the manual.
Once you’ve deburred the edges of the Fwd Top Fuselage Skin, it’s important to follow the manual workflow and remember to break the side edges prior to dimpling!
As I clecoed on the top skin, I found that a few flanges on the Subpanel needed a little more fluting depth in a few places to improve hole alignment.
Then it’s the same workflow as for the side hinges … clecoing a reference hole, and then having clamped the hinge in position, match drilling.
You keep the hinge in the correct position by keeping parallel to a reference line drawn on the hinge. But I found a little guide I had made when doing the side hinges, and used that as well.
Small cleco clamps either side of the hole to be drilled kept everything nicely in place.
Left side all done …
… and the right side : )
Before taking it all apart there are a few holes to be final drilled.
And then once the skin is removed, some hole deburring and a bit of dimpling.
I had to remove a bolt in the Canopy Hinge Ribs to get access for one of the holes that needed a dimple.
Because of the small flange depth I also used a reduced diameter female set.
This is how I jigged the curved hinges to enable the countersinking to be done using the drill press.
The #30 holes in the top longeron also need to be countersunk … gulp!
Can’t afford to get these wrong!
So I took my time, and taped on a piece of material to match the depth of the side skin, enabling a relatively stable base for the countersink cage.
It all worked out, but I was pleased to get this job behind me!
Then the top skin can be dimpled.
Next job … back in to the spray booth to prime/paint the pieces.