With the wings comfortably installed in the wing cradle, it's time to do some small catch-up work.
One of the remaining tasks on the mainwing is the installation of the access doors. These were matchdrilled to the main wing spar before and primed, but I still had to matchdrill them to the bottom skins.
There are 6 access doors, 3 in each wing on the bottom side.
To matchdrill, I installed the access plates to the main spar using #6 screws and #30 cleco's.
Pay attention here ! The holes in the skin are for #8 screws (8R8) so you need to enlarge the hole with a #19 drill. Going from #30 to #19 with one drill is not a good idea in this thin skins.
I stepped up to #19 using #30, #28 and #21. This ensures that the hole is nice and round since the last step is very small.
In the next image, the bronze cleco's are now black clecos and all holes are ready for 8R8 screws.
After matchdrilling, removed the skin from the wing (for the 100th time) and using the nutplate drill jig tool for #8 to drill the nutplate ear holes. Actually, I drilled all the left ones by hand and then inserted the tool for the right one to ensure alignment.
Then used the squeezer to dimple both #8 and #40 holes to accept the screws. The 8R8 are countersunk screws so they set flush with the skin.
A close up view on the dimples. You'll need to dimple the center one first, and then use a more narrow female dimple die to do the outside ones.
Then needed to dimple the nutplate ears. I like to make my life easy and the picture below shows my favorite way to dimple small items like nutplates and stiffeners. Just put the yoke in a vise and make sure you can move the trigger. It saves you from carrying a lot of weight and load on the elbow.
There are a lot of nutplates on these access doors.
Next job is to rivet the nutplates on the skin. I used the pneumatic squeezer. Some are more difficult to set (especially towards the edge of the skin) since the skin is very floppy and tends to move as you squeeze.
And here is the finished product.
