Boseís Guns offers Heavy Zinc Phosphate Parkerizing
Finishes. Parkerizing, or phosphate coatings, have been used for years in
various forms due to their oil trapping, non-reflective characteristics
when used in severe weather conditions. Typical Parkerizing finished color
is dark gray but may vary based on the type of alloy in the steel. Color
variations are achieved primarily by use of different lubricants such as
Cosmoline, linseed oil, gun oil etc.
Bose's Guns also offers Manganese Phosphate Parkerizing Finish. This
finish is one of the most durable in the industry. The manganese will give
a coarser and more porous finish than other phosphates. This finish also
meet standard mil-spec MILL-STD-171 for small arms finish. If extreme use
is what you need this is the finish for your firearm.
Process of Parkerizing
Phosphate coatings provide an excellent surface for holding a rust
inhibiting, or lubricating compound. Oil is absorbed by the
microcrystalline structure, and has the effect of a lubricant reservoir,
which aids break in of friction bearing surfaces. Whereas, untreated
surfaces of steel are unstable and corrosion-prone. Phosphate coatings are
much more resistant to the elements. Phosphate solutions consist of zinc,
manganese, or iron, dissolved in carefully balanced solutions of
phosphoric acid. When a ferrous type, or reactive metal, is placed on the
phosphate solution, a light acid etching takes place. Shortly thereafter,
depending on the accelerators used, a micro amount of metal is removed
from the surface, and a hydrogen process takes place, which in turn
precipitates a phosphate coating on the steel, which is integrally bonded
to the metal.
Once applied, the coating can now act as a corrosion
resistant to the metal, as well as improve wear resistance. The time and
temperature of immersion can be critical, depending on the amount of
solution used, as well as the identity of the metal being treated. Zinc
Phosphate treatments will generally produce a crystalline deposit of
hydrated zinc phosphate compoundís on the base metal, and normally have
a coating range between .05 to 1.5 um in thickness, and can vary in
density and porosity. The variability of density and coating thickness is
not a reliable indicator of the corrosion inhibiting qualities of the
finished product. The appearance of the zinc phosphate coating is a gray
matte finish, with the shade varying somewhat, depending on the chemical
composition of the treatment bath, and the amount of ferrous material in
the metal. The zinc phosphate coating has outstanding corrosion
resistance. This occurs because it provides a chemically inert and
The Parkerizing Process:
1. Complete Disassembly and Inspection of Parts
One of the most important parts of the operation in regards to the
function of the firearm. Parts are inspected for wear or damage and
the customer is advised on what it will take to put the firearm back
2. Degrease and Chemically Remove Blue/ Rust From All Metal Surfaces
That Will Be Blued
This is a key process in removing and stopping rust in all areas.
Polishing will not reach into the internal parts of the firearm this
is where chemically removing the blue leaves the part true to its
original dimensions with the blue and rust removed.
3. Metal Finish
The firearm is ready for the desired finish, which for this process
the parts will be bead blasted.
4. Chemically Cleaned Metal
The parts are soaked in a slightly alkaline detergent cleaner that is
formulated particularly for cleaning guns prior to Parkerizing. The
solution removes and suspends all grease, dirt, and built-up crud. The
soak is strong enough to do the job right, yet safe and harmless to
the steel and us. All parts will leave this step surgically cleaned,
which leads to a beautiful finish. 50% of the problem with Parkerizing
can be traced back to the cleaning process
5. Flowing Water Rinse Tank
Strangely enough, clean, clear water that is safe for drinking is not
necessarily safe to Parkerize with. Here we use charcoal filters to
make sure we have no contaminates in the water that will mess up the
chemical balance of the Parkerizing solution. We use this tank to
remove any traces of the cleaning solution.
6. Hot Parkerizing
This tank is the only tank that has to be stainless steel. Otherwise,
the Parkerizing solution would parkerize the tank instead of the
parts. The solution in the tank is made up of 4 oz. of Parkerizing
solution per 1 gallon of water. The tank is held at a temperature of
160-170 degrees. The parts are suspended in the solution and allowed
to react. We turn the parts periodically to get an even treatment.
Parts are in this tank for about 40 minutes.
7. Flowing Water Rinse Tank
This is the same tank as above except, we are rinsing off the
Parkerizing solution from the parts. Once they are done in this tank,
each part is thoroughly inspected to ensure the Parkerizing process is
All parts are dried.
9. Post Treatment Solution Bath
This part of the process seals the Parkerizing.
10. Wipe Down
Wipe excess oil off the parts with soft cloth and reassemble the
Time required to perform these steps will vary depending on the type,
age, style and condition of the firearm.
Our experience in this industry will allow us to answer your questions and
take care of the majority of your needs. The services we offer may require
us to see your firearm in order to quote a price. You can send us pictures
via email and/or scanned pictures.
Please contact us
for an estimate or for more details on getting an estimate today.
Please review our Parkerizing pages by using the navigation to the left
or if you have a question or cannot find a service. Please let us know.
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