Rust Finish

[marc_reusser]

This was done to simulate rust as it would occur on an exposed exhaust pipe. A surface which is regularly heated and cooled, and exposed to the weather, thus obtaining both a dark base color, with a worn surface, and multiple layers of  more freshly oxidized flakes, and texture.

The part was smooth injection molded plastic. The exhaust pipe was drilled out to obtain a thinner wall thickness. The dents were first drawn out with a pencil to make sure the locations looked correct (used tip from Adam), and then made using a small Dremel round headed bit. Final shaping and blending were done with 400 grit wet sandpaper.

The surface texture was created using Bragdon's Rust Powders mixed with Plastruct liquid styrene cement. Using an old brush, the surface was given a coat of solvent to soften it. While tacky, the entire surface was then coated with a mixture of "Soot" and "Medium Rust" for the darker base coat. When pretty much dry, using another old brush with the bristles cut short, the brush was dipped into the solvent and immediately dipped into lighter rust colored pigments, and then stippled onto the surface.....softening the surface, making it "tacky" and creating a raised texture of varied colors. This was done repeatedly in multiple layers to obtain the coloring, layering and depth desired. Once satisfied it was set aside to thoroughly dry. When dry, some additional "Soot" color was added to the end of the exhaust.

The silvery-grey areas are intended to represent where an adjacent object has recently rubbed against/come in contact with the an adjacent surface/object.


Marc

[MikeC]

Very realistic, Marc!

While tacky, the entire surface was then coated with a mixture of "Soot" and "Medium Rust" for the darker base coat.

What method did you use to coat the tacky surface? When I first read your description, I visualized "dunking" the tacky part in a small container or bag of Bragdon's - but you may have done something else completely.

[marc_reusser]

Mike,

I merely used a brush to quite liberally coat it. Basically applying so much powder that initially the brush has very little contact with the tacky surface. Once I got enough powder onto it the tackyness dissapears to a large degree, and one can lightly brush on more. When it had pretty nuch set/dried, I brushed off the excess, and also lightly burnished the surface in the process. (you are probably familiar with this from your working with the powders). Then I went on to the next step.

If carefully done, dunking could work....the trick would be though not to let the tacky part come in contact with any oject or sides of the baggy, as this would cause it to stick to it, or at the least deform the surface. When I say "tacky"...I am describing a very softened surface 

BTW., part of the inspiration for the texture and coloring were printouts I had of those "burn barrel" photos you once posted on RRL.


Marc