Wrinkle Finish

Q. I am painting a machine tool sheet metal cover and having a hard time finding someone who can apply a wrinkle finish. All of the machines I work on are in the neighborhood of a half million dollars, so the need to match them is big! Help! J.S.

 

A. For the record, wrinkle finishes form wrinkles on their surface because of differential drying of the surface and the coating interior. The surface of the film dries and expands while the underlying portion of the film is still fluid. In the 1920s and ’30s, tung oil played a prominent part in this phenomenon. Wrinkled finishes were available in many variations, from suede to deeply furrowed undulations.

Without getting into the chemistry of the coatings, coarseness of the “wrinkle” depends on the choice of vehicle co-resins and choices of film drying agents. I haven’t seen wrinkle finishes on new products for many years because they are dust collectors, very rough and hard to clean. Are you sure you want to apply a wrinkle finishe? Perhaps you want a textured finish.

Textured finishes are divided basically into two types: single-coat and two-coat. A single-coat textured finish is composed of two incompatible resins which form a continuous phase and a discontinuous phase. The continuous phase is the film former and the discontinuous phase forms the texture as lumps or bumps. On the other hand, the two-coat type is applied as a full coat followed by a spatter coat. To get the correct texture, the spatter coat must be applied using a specific spray gun having a specific spray nozzle at a specific pressure. Now you can understand why it is so difficult to find someone who can apply your finish!

To solve the problem, you must find out the specific material used on the machines in question. Next, you must find out the specific equipment used to apply that material. Finally, take that information to your custom coater. He should be able to help you.