PTFE Coated Copper and Brass
Teflon® and Xylan® coatings are well suited when it comes to being applied to copper and copper alloys and although copper and copper alloys are noted for their strength and corrosion resistance, copper will slowly tarnish by means of gradual build-up of an oxide film when exposed to the atmosphere, and the formation of copper salts (sulphate and carbonate) will occur on the surface. Aluminium bronzes and copper-nickel alloys behave slightly differently, these alloys quickly form a strong and tenacious oxide film inhibiting any coating to be applied. Therefore, for the application of a Teflon® or Xylan® coating onto copper and copper alloys relies heavily upon the surface preparation, without the required preparation and surface coating will potentially fail due to lack of adhesion, brought about by the underlying oxides. Abrasive mediums, such as steel wool and other proprietary pads such as "Scotchbrite" are to be discouraged.
PTFE Applied Coatings can advise on the appropriate pre-treatments required to overcome the issues surrounding the application of Teflon® and Xylan® coatings onto copper and copper alloys. The most important element when dealing with copper and copper alloys is timing. The time between surface preparation and the subsequent surface coating is to be kept to a minimum to avoid the formation of surface oxides. The strength of the bond between the substrate and the PTFE coating requires high adhesion values relies upon the removal of surface contaminants.