Here's the bottom of the wing with all the skins attached.

The final process in fabricating the bottom wing surface is adding the stiffeners to the first three panels each side of center.

Make sure to take the extra time to label everything.

Notice that we labeled the skins BC and LB1. This stands for Bottom Center and Left Bottom Panel 1.

Each individual stiffener is also labeled and notations are made in our builders log.

Remember, you're going to have to take all the skins off again and then reassemble it with the epoxy bonding glue. Label everything.

It's finally time to start skinning the top surface.

The first thing you do is remove the bottom center skin.

When attaching a new skin, we always try to start from the center of the skin and work towards the edges.

You'll notice our pre-drilled, inch and a half, ruler clipped on. More on this in the next picture.

Here's our normal procedure for using the pre-drilled ruler.

• Locate the first hole with a blind hole locator tool.
• Locate the last hole the same way.
• Use a heavy Sharpie marker to draw a line between the two holes.
• Clecoe the ruler into the first hole.
• "Sight" the line through the predrilled holes.
• Start drilling every second hole, clecoeing as you go. Spot check from the rear to make sure you're getting a good location on the rib flange.
• After every other hole is drilled, drill the non-clecoed holes and remove the ruler.

The top center skin is now in place.

We're ready to begin the LT1 and LR1 side skins.

Bottom view of the Top Center skin.

To do the next two panels, we reattach the bottom center skin, and remove the bottom skin for the next two panels.

Reattaching the bottom skins, as we go, makes sure that our washout angles are maintained as we add more skins.