Modeling Corrugated "metal" (Painting and Weathering) HOW TO DO IT!!!!???? - Model Railroader Magazine

Congregated siding using plastic can be a challenge. First off, congregated siding is made up of panels. I'm not really sure of the standard size, but 4x8 comes to mind as does 5x10 and 6x12. The congregation lines run lengthwise on the long dimension. Once the panels are applied, each starts to weather independently of the other, thus each can be a different shade. Sometimes congregated buildings were painted. And again, each panel can take the paint differently causing a different shade.

So, the first thing that I would do is scribe some panel lines if the building doesn't already have them. The next thing is pick about three different shades of the same color paint. You are probably going to have to mix these yourself. For instance, for a non painted building, take your basic silver and make up three shades in three small containers. You don't even have to save the paint once mixed and used because the more variation, the better. Anyway, leave one as it is straight out of the bottle. In the second, add a little black or brown paint. Not much, just a drop or two to change the SHADE, not the COLOR. For the third, add a drop or two of a light color like white or gray.

Now start painting each panel a different shade of the basic color. Try not to paint the same shade next to each other although you may have to in some places. You can use the same brush if you don't load it up to heavy with paint each time. Once you have the building painted and it is dry, if you want some rust, dry brush some roof brown on some of the panels at random. The rust will occur at the bottom of the panels first, darker at the bottom. The best technique that I have found is paint them with the brush stroke from the bottom up. Lastly, use chalk for an overall weathering effect and clear coat the building with a clear flat to fix the chalk weathering on the building.

This is one of those things that you are going to have to experiment with and develop your own variations of the technique. Is is also time consuming because you have to paint each panel to get the correct effect.  Sorry I don't have pictures.

Elmer.

The above is my opinion, from an active and experienced Model Railroader in N scale and HO since 1961.

(Modeling Freelance, Eastern US, HO scale, in 1962, with NCE DCC for locomotive control and a stand alone LocoNet for block detection and signals.) at home, and N scale at the Club.