To make it easier to write, I've split the base into 3 main areas - the main metal plating the floor is made up of, the vent cover laying on the floor, and the 2 pipes that run under it.
Base Step 1
- Plating
- Basecoat of 50/50 Chainmail + Chaos Black
- Vent Cover
- Basecoat Tinny Tin
- Pipes
- Basecoat 1st pipe (VMC) Burnt Cadmium Red, and the 2nd pipe Snakebite Leather
Base Step 2
- Plating
- 1st highlight using Chainmail
- Vent Cover
- 1st highlight using Shining Gold
- Pipes
- 1st pipe highlighted using 50/50 mix of Burnt Cadmium Red + (VMC) Carmine Red; 2nd pipe highlighted using 50/50 mix of Snakebite Leather + (VGC) Golden Yellow
Base Step 3
- Plating
- Final highlight of Silver
- Vent Cover
- Final highlight of Shining Gold
- Pipes
- 1st pipe's final highlight was Carmine Red; 2nd pipe's final highlight was Golden Yellow
Base Step 4
To help give the base a more natural look, I decided to "weather" it a bit.
On the metal plating, I used several thin washes of (VMC) Smoke, concentrating on the areas directly under the miniature and the recesses to build up some shadow.
For the vent cover, I used some watered-down (VGC) Jade Green, applied in the crevices - then, once it was dry, I picked out areas of the jade in (VMC) Verdigris for some variation in tone.
Finally, for some rust patches, I stippled some Dark Flesh onto areas of the plating, and picked this out with some (VGC) Hot Orange and finally a tiny bit of (VGC) Orange Fire.
After that, all that was left was to take some good old trusty Chaos Black and tidy up the edges of the base.