Applying Sheet Metal Textures

After cutting or sanding a small scale model to reshape it's appearance, you will often lose all or part of the details that were originally included in the casting. Trying to engrave or scratch those features back into the surface can be very time consuming and frustrating. If you make a mistake, you must fill it in or sand it off and start over. I have found an easier way to add some detail back into models that is much more forgiving. It involves imprinting the details on a thin sheet of metal and then applying the metal to the model.

Materials Needed:
This is a trick I stumbled upon at work. We use aluminum laminated tags to label parts. The tags are cardboard with sheets of alumnimum foil on both sides. When you write on them it imprints what you write. That way, even if the ink washes or wears off, you can still read what was written. We also have tags that are similar but a single sheet of aluminum and have an adhesive backing. These tags can be found in various styles and sizes online at Gemplers or McMaster Carr or at an industrial supply store.

Creating the Detailed Surface:
The first step in my process for doing sheet metal textures is to get as detailed a picture as I can find of the area I am wanting to recreate. After that, I measure the area on my model that I am going to apply the texture to and then lay out those dimensions on the foil. If the area is larger than the tags you have on hand, you can sometimes break it up into individual panels much like they do on the real machine. Also, if the pattern repeats over the entire surface, like a corrogated grill for instance, you can just make sure the patern you create is large enough to cover the desired surface, and then trim it to fit when you apply it.

Once you have the dimensions laid out on the foil, you can use pen to draw the details. You can also use other pointed instruments to create details of varying size. A knurled ratchet handle or ribbed bottle cap can be used to create different textures. If you have another model with a surface similar to what you are trying to recreate, you can place the foil on that surface and rub it with a pencil eraser to copy that texture. Be careful not to try to create details that are too deep or you might tear the foil. However, you want the details to stand out enough that they will still be visible after you apply the paint. When you finally have the textures and details just right, you are ready to apply it to your model.

Applying the Surface to Your Model
Great care must be taken during this stage not to damage the thin sheet of metal you have created your design on. The metal foil is very fragile and it is very easy to crease it or make an unintentional mark with a finger nail. If you use the adhesive backed foil, all you need to do is to position it on your model and carefully press it into place. Again, be careful not to press too hard and flatten any important details. The process for non-adhesive backed foil is similar, except you must first apply glue to the surface before you put it in place.

Tip: The adhesive foil is very clean and easy to apply. However, by gluing it into place, the glue will help fill any cavities between your foil and the model surface, helping to make your finish more durable.

Finishing Touches:
The foil will be slightly raised from the surface around it, which may or may not be your desired result. If you want the foil surface to be flush with the area around it, apply a small amount of body filler around the edge and carefully sanding it down. When painting, be careful not to get the paint or primer too thick or it will hide all your hard work. If necessary, you can go back while the paint is wet and re-draw important details before applying a final coat of paint.