Weathering started by sealing the green and red paint with a semi-gloss acrylic varnish. It was followed by a wash of burnt umber all over the model, switching to pure lamp black
on a few spots. Once dry, I used the sponge method to simulate old
(dark brown) and new (light green) paint chipping, mostly on corners and edges. Sometimes I used the
first over the second. Next I applied a good amount of dust and earth
pigments diluted with mineral spirits over horizontal surfaces,
recesses and depressions - wherever dust would accumulate. Once dry, I
used streaking fluids to make dripping marks.
final weathering step was the application of lubricant deposits and
leaks. Of course the effect was concentrated around bearings, movable
parts, but I also added the effect around some bolts, as it could
easily pass as condensed steam.
metalic parts were painted with Tamiya and Vallejo acrylics. I hate
metalic acrylic colors, but since was a not-so-serious project, I
preferred to use the few I have than throwing them away, The secret is
to keep them looking like cast metal parts, and their acrylic nature
helps a lot in this regards, because their pigments are not as thin as
in the enamel/lacquer counterparts. I used them on the crankshaft,
crankshaft bar and linkages.
The flywheel and the scratchbuilt pulley were painted in Tamiya Flat Black (XF-1) and rubbed with Uschi van der Rosten Iron and Steel metallic powders.