One stiffener clecoed to the skin, positioning the others.

Drilling the second batch of stiffeners.

Again, cleaning off fingerprints and other dirt with Acetone.

Pretty aggressive liquid...

Skin ready to be primed.

All training project parts ready to be primed plus some scrap pieces. We treated the scrap pieces differently to see the adverse effect or wheter the primer will even hold onto a "bad" piece. It was already late, so we called it a day...