Parkerizing


    “Parkerizing” or Phosphating is different process in which either zinc or manganese phosphate is used to add a protective coating on metal parts. The temperature the solution is heated to is much lower than that of the Caustic Salt Bluing process and it is an acid process where hot salt bluing is caustic. Parkerizing has been around since the 1800s and is most common on military firearms. But is also popular on  firearms that a greater level of protection is required. The preparation can be fast as the phosphates will not adhere well to polished parts so parts are generally just bead blasted. The green/grey color seen on many older firearms is not the actual color of the Parkerizing as all Parkerizing or phosphating starts out black. The color you see is as a result of the oils and cosmoline  left on the firearms over years of storage.

 

Very rough High Power that I parkerized and blued.

Very rough High Power that I parkerized and blued.

    Zinc Parkerizing provided a thinner finish and is used where tight tolerances are required where Manganese Parkerizing provides a heavier finish which in addition to adding more protection can help to tighten up old parts such as the slides on old 1911 handguns. Manganese Parkerizing thickness can be manipulated both by light carding or polishing and by length of time in the heat tank. Both methods of metal finish provides more protection than either of the methods of bluing making it a great finish for firearms subject to harsh use or weather. As with the bluing methods, how well Parkerizing protects depends on the preparation.