Posted: 1/27/2009 1:35:05 AM EST
I just got back from deployment, when I got back I opened the handgun safe and my HK vp70z was rusted pretty bad I have cleaned it off pretty much, i may have to hit it with a soft brass wire wheel and more CLP. I really think I need to get a protective coat on the gun. any suggestions on coating it? I dont really know why this happend...
Going on deployment like that, whether you thought it would rust or not, you could have stored it in cosmoline, but that's a PITA to deal with.
You could try coating the gun with that bake-lite stuff or some form of camo paint that might have a sealant in it.
Thank you for your service.
For guns I put up I use Hoppe's gun grease. Put a thin layer on everything and it should be fine. Its not all that bad to clean off.
RIG. Rust inhibiting Grease. Get a Rig Rag while you are at it. Old school, but it works great.
I dont really know why this happend...
The oxidation of iron metal.
When in contact with water and oxygen, or other strong oxidant or acids, iron will rust. If salt is present, for example, in salt water, the metal rusts more quickly. Iron metal is relatively unaffected by pure water or by dry oxygen. As with other metals, a tightly adhering oxide coating, a passivation layer, protects the bulk iron from further oxidation. Thus, the conversion of the passivating iron oxide layer to rust results from the combined action of two agents, usually oxygen and water. Other degrading solutions are sulfur dioxide in water and carbon dioxide in water. Under these corrosive conditions, iron(III) species are formed. Unlike iron(II) oxides, iron(III) oxides are not passivating because these materials do not adhere to the bulk metal. As these iron(III) compounds form and flake off from the surface, fresh iron is exposed, and the corrosion process continues until all of the iron(0) is either consumed or all of the oxygen, water, carbon dioxide, or sulfur dioxide in the system are removed or consumed.
Chemical reactions associated with rusting
The rusting of iron is an electrochemical process that begins with the transfer of electrons from iron to oxygen. The rate of corrosion is affected by water and accelerated by electrolytes, as illustrated by the effects of road salt (calcium chloride) on the corrosion of automobiles. The key reaction is the reduction of oxygen:
O2 + 4 e- + 2 H2O → 4 OH-
Because it forms hydroxide ions, this process is strongly affected by the presence of acid. Indeed, the corrosion of most metals by oxygen is accelerated at low pH. Providing the electrons for the above reaction is the oxidation of iron that may be described as follows:
Fe → Fe2+ + 2 e−
The following redox reaction also occurs in the presence of water and is crucial to the formation of rust:
4 Fe2+ + O2 → 4 Fe3+ + 2 O2−[]
Additionally, the following multistep acid-base reactions affect the course of rust formation:
Fe2+ + 2 H2O ⇌ Fe(OH)2 + 2 H+
Fe3+ + 3 H2O ⇌ Fe(OH)3 + 3 H+
as do the following dehydration equilibria:
Fe(OH)2 ⇌ FeO + H2O
Fe(OH)3 ⇌ FeO(OH) + H2O
2 FeO(OH) ⇌ Fe2O3 + H2O
From the above equations, it is also seen that the corrosion products are dictated by the availability of water and oxygen. With limited dissolved oxygen, iron(II)-containing materials are favoured, including FeO and black lodestone (Fe3O4). High oxygen concentrations favour ferric materials with the nominal formulae Fe(OH)3-xOx/2. The nature of rust changes with time, reflecting the slow rates of the reactions of solids.
Furthermore, these complex processes are affected by the presence of other ions, such as Ca2+, which both serve as an electrolyte, and thus accelerate rust formation, or combine with the hydroxides and oxides of iron to precipitate a variety of Ca-Fe-O-OH species.
Rust is permeable to air and water, therefore the interior iron continues to corrode. Rust prevention thus requires coatings that preclude rust formation. Stainless steel forms a passivation layer of chromium(III) oxide. Similar passivation behavior occurs with magnesium, copper, titanium, zinc, aluminium.
An important approach to rust prevention entails galvanization, which typically consists of an application, on the object to be protected, of a layer of zinc by either hot-dip galvanizing or electroplating. Zinc is traditionally used because it is cheap, adheres well to steel and provides a cathodic protection to the steel surface in case of damage of the Zinc layer. In more corrosive environments (such as salt water) cadmium is preferred.
Galvanization often fails at seams, holes, and joints, where the coating is pierced. In these cases the coating provides cathodic protection to metal, where it acts as a galvanic anode rusting in preference. More modern coatings add aluminium to the coating as zinc-alume, aluminium will migrate to cover scratches and thus provide protection for longer. These approaches rely on the aluminium and zinc oxides protecting the once-scratched surface rather than oxidizing as a sacrificial anode. In some cases, very aggressive environments or long design life, both zinc and a coating are applied to provide corrosion protection.
Several other methods are available to control corrosion and prevent the formation of rust, colloquially termed rustproofing:
Cathodic protection is a technique used to inhibit corrosion on buried or immersed structures by supplying an electrical charge that suppresses the electrochemical reaction. If correctly applied, corrosion can be stopped completely. In its simplest form it is achieved by attaching a sacrificial anode thus making the iron or steel the cathode in the cell formed. The sacrificial anode must be made made from something with a more negative electrode potential than the iron or steel, commonly zinc, aluminium or magnesium.
Bluing is a technique that can provide limited resistance to rusting for small steel items, such as firearms; for it to be successful, water-displacing oil is rubbed onto the blued steel.
Rust formation can be controlled with coatings, such as paint, that isolate the iron from the environment. Large structures with enclosed box sections, such as ships and modern automobiles, often have a wax-based product (technically a "slushing oil") injected into these sections. Such treatments also contain rust inhibitors. Covering steel with concrete provides protection to steel by the high pH environment at the steel-concrete interface.
Another method to avoid rust is to control the environment. Controlling the humidity, if possible, below a certain thereshold can reduce or stop the corrosion process.
Rusting can be controlled also by proper design, avoiding for example areas of stagnant water, galvanic coupling with more noble materials...
Corrosion inhibitors, like gas phase or volatile inhibitors can be used to prevent corrosion in closed systems.
A simple and inexpensive way to remove rust from steel surfaces by hand is to rub the steel with aluminium foil dipped in water. Aluminium has a higher reduction potential than the iron in steel, which may help transfer oxygen atoms from the iron to the aluminium. The aluminium foil is softer than steel and will not scratch it, as steel wool will, but as the aluminium oxidizes, the aluminium oxide produced becomes a fine metal polishing compound.
Hey....I sold my VP70z to a guy who was deployed to Afghanistan last year.
Anyway, a thin layer of oil, and a dessicant can keep your guns good for a while.
ok thanks for the help, no I have had mine for about 5 years now, a guy thought it was some kind of hipoint and i picked it up for $250 . thanks a bunch again.