I put together my first competition build in 2016 for the GBWC. I ran a few tests first on a 1/144 Barbatos form 4 and a 1/144 graze, but besides those models I hadn't touched a gundam kit in 14 years!
This kit was heavily inspired by the "real robot" side of the mecha genre. I wanted to build something that had an imposing presence but could still function in a science fiction universe as a piece of military equipment.
The build is mostly Grimgerde with a splash of Graze thrown in for the head and chest mods.
Let me take a moment to give Dupli-Color a free plug for their sandable primer. This stuff is amazing! It achieves the seemingly impossible dichotomy of both preserving fine detail and covering small scratches while maintaining sandability. I sprayed the inner-frame black and the armor grey.
I used Tamiya paints for the most part, thinned with X-20A primer. After a coat of X-10 gunmetal on top of the primer I gave the inner frame a mid-weight drybrush of Citadel's Leadbelcher followed by a light drybrush of Mithral. Finally I gave the whole frame a coat of dark tone wash from Secret Weapon--great washes, better than Citadel (and cheaper!).
For the armor I first put down a coat of XF-67 NATO Green and then painted shading on top of that with XF-63 German Grey, then back to NATO Green for the top coat. I focused the second green coat on the center of each armor panel to bring out the shading.