Between Polishing & Bluing Rust Preventive
A freshly polished gun, which you have spent hours getting into beautiful condition for bluing, is a prime target for surface rust if it is not going into the bluing tank immediately. A few hours under some conditions - between final polishing and bluing, can result in fine "silver" spots showing up on the gun after it has been blued. These are a result of microscopic rust spots developing following polishing, and prior to bluing. High-powered rust preventives should not be used during this storage period, because they are difficult to remove and, if not completely cleaned off, will result in a "gray" bluing job. Brownells HOLD is the modern answer to in-shop storage of parts, prior to final finishing. It chemically engages free oxygen and neutralizes all acidic impurities, (including fingerprint acids). No petroleum additives are included in this modern rust preventive; therefore, oily surfaces are not a problem. Polished, HOLD-treated parts may be put right into the 909™ Cleaning Tank with no change in your regular bluing techniques. Application is either by spray (pint spray bottle is furnished), or by immersion. Small parts may be immersed indefinitely in HOLD with no possibility of rust ever forming. Can be used on all metals except aluminum, magnesium, and cast iron such as engine parts. HOLD is non- caustic, non-acid, non-toxic, non-flammable, inexpensive and easy to use. HOLD-treated gun parts will withstand indefinite in-shop dry storage.
Big Book Catalog, Issue:69, Page:395