After reading a post earlier this week regarding simulating rust I checked out one of the products that was discussed is a link to another forum. The product is called "Rust Antiquing Set" by Sophisticated Finishes. It is a 2 part process. The first is a paint that has suspended Iron filings in it. It works on just about any material. You just paint the object with the paint and let it dry for at least 12 hours. Once dry you brush the solution onto the surface. I can only figure that it causes a reaction with the iron filings and soon you can see the rust developing. Directions state that the solution can be applied directly on iron to cause the rust. Best part of all it is available at Micheals Craft stores. Cost was less that $10.00 with my wife's coupon and the kit will cover 3 sq. feet.
This picture shows the process as applied to the plastic girders that
are usually included with the Lionel Tractor Trailers. Note the differant
variations in the "rust". I believe this happens when three is more of
the solution that pools up or is applied havier. It is possible to go back
and apply another coat of the solution as well. The surface even has a
rust texture to it.
Another picture showing the variation. Just like mother nature does it!!
The picture below shows the process as applied to one of the chrome
culverts that are supplied with the operating culvert cars. The rust texture
is unbelievable on these. Also shown is the 2 bottles included with the kit.
Also in the picture above you can see the ends of some girders that I painted
last night and had just applied the solution to.
Give it a try. I think you will be pleased with the results