The Corrosion shader (if you're talking about the one that I posted in the free stuff section) uses multiple layers of cellular coloring and bumping. The same cellular pattern and scale is used throughout the shader. To change one means that you should change them ALL if you want the patterns and bumps to match up. To do that, first drop the the shader onto your object. Then go to the texture room and expand the various layers of the corrosion shader. Wherever you find a Cellular shader, adjust its scale accordingly. Hope this helps. Mark