And it is simple to use,just brush or sponge it on the surface to be painted and the cracks just appear.The thicker the application of paint the smaller the cracks.For the barnsiding look use Silverwood stain as an undercoat.Individual flakes can be picked off using an xacto knife,tape or gentle knife scrapping .The jury is still out in regard to using this technique on plastic but I will keep you guys informed after further experimentation.

The look that I am trying to achieve here is a bleached, sun baked surface that may have seen some rain sometime in the past.The nail or screw holes were made with a sharp needle in a pattern that indicates some kind of framing structure beneath.I deliberately did not line them up in rows like rivets.I want it to look like it was done by a human hand not machines.
After punching in the holes I came back with a sharp HB graphite pencil and twisted a little graphite into each hole to create a nail or screw head.The graphite works well as it has a slight shine to it like it was metal.
I then took some very watery raw umber and with a bristle toothbrush I flicked on a spray of paint to look like crud ,mud or fly sh.t etc...Then with a small round brush and some very watery burnt sienna I touched every nail head and the wood swelled back to level again and soaked up a little rust staining.Try to be subtle when using this technique.Now I will do a little shading with chalk pastels in all the nooks and crannys.I do all my old barnsiding the same way using birch coffee sticks or tongue depressors.Do not seal the wood prior to painting.
This is a long tedious process but I think that it is worth the effort in the end.

A lot of work to make what looks like an old chicken coop ! Undecided This section has yet to be treated with the burnt sienna rusty nail heads look.Although they are hardly noticeable they do add a lot to the finished product.When weathering try to treat each area as a artist would do when painting.Make it interesting for the eye and try not to line things up in rows and right angles etc....or use monotone colors. Treat each piece as an individual part of the whole and put your best effort into it no matter how insignificant it may seem at the time.Avoid trying to rush through the things you don't particularly like doing.

Here is a cool old wood study pic ! The paint looks like it was once a red color that has now faded to orange.The surface looks like it is beyond the cracked paint stage and only a little of the paint stain remains.In this damp environment and a little greenish moss has developed where the wood nears the earths surface.Not a worry in the desert.

OK now here is the finished product ! All it needs is a chicken in the window.This is what I love about wood , nothing can replace the real thing.Each piece is unique and different and has a character of its own.

Here is one of those circumstances in modeling where a compromise of some kind has to be made.The bench is to scale but the wall of the car is a little too thick which moves the bench seat a little too far into the aisle.(no conductor is that slim) Lucky for me that all the benches are not required to be side by side
as in a normal railway car.I can cheat a bit in the arrangement of the benches and it won't be noticeable.This is one of the difficulties you run into when scatchbuilding by eye alone.