Cost Savings Corrosion Protection
for Deep Storage
And Preservation of United States
Air Force Vehicles and Equipment
Anna M. Vignetti
4119 White Bear Parkway
St. Paul, Minnesota 55110
The United States Air Force initiated an Air Staff
Level Test Program for the protection of military vehicles and air
ground support equipment. As a result of corrosion, millions of
dollars of valuable assets are lost every year and the need for
war readiness is jeopardized. Many different preservation products
have been evaluated over the years and consequently utilized. This
last initiative was for the evaluation of Vapor Corrosion Inhibitor
(VCI) products and systems in deep storage1 and preservation
for war readiness materials (WRM).
VCIs are chemical compounds having significant
vapor pressures that allow vaporization of the molecules and subsequent
adsorption of these on metallic surfaces2. The advantage
of VCIs is that the vaporized molecules can reach inaccessible areas
commonly found in electronic enclosures, between metal junctures
and similar other systems including fluid reservoirs. VCIs have
the ability to effectively prevent corrosion of dissimilar metals
and provide a desirable effect in protecting metals from corrosive
The USAF criteria and requirements, test details
itself and the results obtained will be described in this paper.
Parameters for the test were identified and established for specific
results at the completion of the initiative. Ease of application,
environment, worker safety, war readiness and enhanced war fighting
capabilities would be positive factors if they could be given within
the established guidelines.
Key Words: VCI (Vapor Corrosion Inhibitors), WRM
(War Readiness Materials), PACAF (Pacific Allied Forces), CENTAF
(Central Allied Forces), USAF (United States Air Force), AGE (Air
Ground support Equipment), VIC (Vehicle in Commission).
In recent years, militaries worldwide have taken
a more aggressive posture in the prevention of corrosion. Corrosion
problems in the military go as far back in history to ancient times
and were treated in various ways. Identification of prevention as
a necessary part of maintenance, operations and storage occurred
during World War II3. Many products and methods have
been used over the years and now, millions of dollars are spent
in research every year in the war against corrosion. The loss of
valuable assets is a major concern, however, more importantly, war
readiness and the prevention of catastrophic failure are primary
in the overall scope of corrosion prevention.
The United States Air Force, like many other US
military branches have taken a bold initiative to make an objective
evaluation of different methods. This paper will detail the test
objective, parameters, environment, the actual test, benefits and
results. The evaluation of Vapor Corrosion Inhibitor (VCI) technology
as a total system of protection was the main purpose of this test
program. The USAF had adopted a chemical preservation storage program,
which was subsequently delayed for this evaluation.
This evaluation was initiated to validate and
compare preservation systems for deep storage of vehicle and air
ground support equipment (AGE) with a commonly used chemical preservation
technology and a newer VCI system. VCI performance on different
metals in industrial and marine atmospheres have been studied and
analyzed experimentally to show corrosion rates as shown in Table
14. VCI products have been used since the World War and
newer VCI technologies have been further developed since that time.
This test program evaluated a system of products as a solution.
The expected life for a deep storage/preservation
system was defined for a 3-5 year time frame, with minimal or no
upkeep. The reapplication of current chemical preservation being
used as well as requirements for exercising, time and labor were
considered. Due to the reduction of forces, reapplication of the
products and exercising of vehicle and equipment assets is difficult
Zero deterioration of equipment was considered
as one of the criteria in considering the VCI system. The desired
result was to achieve a sustained 90% overall vehicle in commission
(VIC) success rate in corrosion protection and mechanical functions.
Minimal mechanical degradation was a critical factor in the test.
Again as a result of less manpower, the decrease of mechanical problems
at break out is critical and necessary in a deep storage program.
There were a number of key parameters set by the
USAF for the program. Preparation for the actual test began with
the identification of the vehicles and equipment to be allocated
for preservation. USAF teams selected and issued orders for the
preparation of the selected assets. The length of the test was predetermined
for a term of one year.
Preparation. The USAF team requested that
the individual sites prepare the assets to be in "excellent"
working and physical condition. The VCI manufacturer then assessed
and calculated product needs based on vehicle and equipment specifications.
The company provided training procedures, materials, equipment necessary;
and personnel to assist and train military personnel for the application
of the VCI products. Contractor and military personnel were deployed
to prepare the equipment and perform the actual preservation. Each
asset was thoroughly inspected and repaired prior to the procedure.
Test Sites. Five locations were chosen
in order to make a fair evaluation in different climatic zones and
atmospheric conditions. Guam was chosen due to the extreme climates
and severe corrosion conditions. The trade winds and high ultra
violet light exposure make this location a suitable choice for the
tropical environment. Two locations in Korea, one located centrally
and the other on the coast, were selected to conduct to give a good
evaluation of the four seasons in two different environments. The
seasons vary from very hot and humid to extremely cold conditions
with a great deal of precipitation. Lastly, two locations in Oman
complete the various climatic conditions requiring testing. Desert
extremes that encompass high UV are found in the first location
and hot, humid conditions are found in the other on the Persian
Gulf coast. The assets location during the time of the test were
determined to include inside storage in climate controlled and bare
sheds and also outside in all climates and atmospheres.
Identification of Assets. The identification
and choice of assets was made to include the widest range of different
vehicles and equipment possible to make a fair evaluation. Specifically,
tactical, road building, personnel vehicles, and AGE. The AGE equipment
included bomb lifts, compressors, trailers, generator sets among
others. Different storage scenarios were made for the same asset
if more than one was used in the test.
Each of the five locations was chosen to preserve
a total of 180 vehicles. Two locations were chosen to evaluate AGE;
being Guam and Osan, Korea. At the time of preservation, it should
be noted that condition and preparation of the assets varied from
fair to excellent. Lessons learned from one location to the next
helped in the preparation, but did not affect the outcome of the
final results. A total of 119 vehicles and 60 pieces of AGE were
used in the final preservation. Ten vehicles of medium size were
chosen for the chemical preservation process.
Products. The products used encompassed
a suite of products with the same and compatible technology to provide
a system solution. Many of these products are already being used
successfully by militaries worldwide. Applicable military specifications,
(Table 2), National Stock Numbers (NSN), Qualified Product Listing
(QPL), and NATO numbers are already in place for most of the products.
From the start, surface preparation was accomplished
with cleaning/degreasing and rust removing products that were modified
with VCI additives to further enhance corrosion prevention. VCI
emitting products were used for electronic compartments and miscellaneous
enclosures, which included large void spaces and the cabs of the
vehicles. Temporary and permanent coatings were used as under carriage
coatings as well as clear, permanent coatings for overall coverage
of selected assets. Lubricating products were used for bare metal
surfaces on moving parts such as forklift chains and hydraulic cylinders.
Additives for fuel, coolants, oil and hydraulic lubricants complement
the internal systems. Finally, the four types of covers utilized
which especially fabricated to contain VCI additive technology.
It should be noted that all of the VCI products used in this test
program were selected to be environmentally friendly.
Application Procedure. A step by step process
was used in the application. Throughout the application of the products,
one to five personnel worked on an individual asset. More than one
procedure could be performed at a time allowing for optimum use
of time and personnel. Military procedure for repair and preparation
of the assets prior to the preservation were part of normal maintenance
Step 1. Prepare vehicle or equipment according
to state or condition desired at time of break out. Complete a thorough
inspection noting discrepancies, condition and record of vehicle
condition. Take pictures showing condition and discrepancies.
Step 2. Remove rust with liquid or wipe
type product both containing VCI additives.
Step 3. Wash down with VCI cleaning product
(Table 2, No. 1). Clean heavy oil or grease with VCI wipe product.
Do not rinse. Allow to partially air dry and wipe down with a dry
Step 4. Apply permanent VCI water base;
clear coating for assets chosen. Apply one coat at a 2 mil (50 micron)
wet film thickness. For severe corrosion conditions where vehicles
will not be stored inside or with a cover, wait 30 minutes to one
hour and apply second coating at a 2 mil thickness.
Step 5. Apply VCI lubrication coating to
all working and moving parts as well as bare metal such as hydraulic
cylinders. Apply paraffin base VCI coating to rusted areas beneath
vehicles or equipment. In accordance with (Table 2, No.2 & 4).
Step 6. Lower liquid levels of coolants,
hydraulic oil, regular oils (Table 2, No.3) to required capacity
for the additives. Fill fluid reservoirs with required VCI additive
product. Calculations for requirements are made prior to application
in order to facilitate their addition. Charts specifying capacities
and measured fluids to be added were provided prior to application.
Step 7. Apply VCI modified lubricating grease
to all areas normally greased including zirc fittings (Table 2,
Step 8. Apply VCI electronic spray (Table
2, No.5) to all electronic/electrical connections, control panels,
wiring, under hood, dash, battery boxes, et al. Apply VCI emitting
devices (Table 2, No.6) to storage and battery boxes, electronic/electrical
enclosures and under dashboards. Place VCI foam pads in large void
spaces and in cabs (Table 2, No.7).
Step 9. Apply chosen VCI protective covers.
Four covers were chosen: VCI polyethylene shrink film, VCI reinforced
films with and without soft interior linings and VCI high UV resistant,
reinforced covers with a soft interior lining. Specifications of
these products are given in (Table 2, No. 8 & 9). Refer to Figure
1, 60K Cargo Loader with VCI Military Shrink Wrap.
Steps 5 through 8 may be performed simultaneously
for efficiency. The process was timed from start to finish.
Evaluations were done concurrently with other storage
tests. Sister services use of VCI products and their successes are
considered in the evaluation, as well as other allied military services
and industry alike. Other storage tests completed as well as different
methods identified over a period of time were bench marks for establishing
parameters for the test, results required to make a storage process
successful, as well as undesired aspects identified with these bench
Testing of VCI performance in industrial and marine
atmospheres was carried out in a field exposure test, Table 1. The
different metals evaluated are, for the most part, the predominant
metals in the vehicles and equipment used for the USAF preservation
evaluation. The length of the test was one year and the purpose
of the evaluation was to measure the corrosion rates in mils/year.
The test site was Cure Beach, North Carolina. The procedure was
- The preparation of the metal coupons were made according to
ASTM G1-90, Standard practice for preparing, cleaning, and evaluating
corrosion test specimens.
- The metal coupons were placed into wooden enclosures.
- Emitting devices (NSN 6850-01-338-1393) were placed inside the
- Enclosures were opened and the metal coupons removed after test
- Corrosion rate measurements were made according to ASTM G1-90.
Results show that the unprotected coupons measured
greater corrosion rates. Correlation of this field test can be made
with the USAF evaluation. In a visual evaluation, vehicles and equipment
protected with the VCI system did not show any signs of corrosion.
A thorough inspection and extensive photographic
records of the assets were made prior to storage by military and
contractor personnel. A limited number of preserved assets were
evaluated at 6 months for the PACAF region and at 9 months for the
CENTAF locations. Results of corrosion protection at this point
were impressive. Although high condensation and excessive amounts
of water were experienced in the preservation in the Pacific Rim
locations, better than a 90% rate of corrosion protection was achieved.
After removal from storage, the vehicles were placed into areas
that would provide heavy use for a period of 90 days. The goal of
zero defects was accomplished and mechanical failures were not reported
as a result of the VCI protection system used.
In September of 2000 (after 12 months of preservation),
the PACAF assets were de-preserved. Photographs and extensive evaluations
were made to record the condition of the assets. Indications and
physical results show that the corrosion protection and mechanical
soundness exceeded the 90% VIC. Removal of the covers took at the
most 3-4 minutes. The start up of the vehicles took the major portion
of the recorded time in the depreservation procedure. Removal of
any of the VCI products other than the covers was unnecessary and
will continue to provide protection to the assets. Immediate war
readiness was accomplished.
Chemical preservation products
Ten vehicles were designated for the traditional
chemical preservation. The evaluation shows that the application
and removal time involved make this a costly alternative. The application
of the exterior and interior products was very specific and detailed.
The assets were stored inside and were not exposed to outside climatic
conditions. Application time per vehicle was up to 4-5 days. The
necessity to practically pull the vehicles apart made it very time
consuming and labor intensive. Break out times ranged from 5.5 to
6 hours per vehicle. The use of flammable solvents made this a hazardous
removal and cumbersome work practice.
VCI Product application
The application of the VCI system has been analyzed
by vehicle, cost of the VCI products, and the labor/man hours required.
A brief analysis is presented in Table 3. Additional time and labor
were not required for the application process. Break out times averaged
at 18 minutes per vehicle. This included the removal of any cover
used and the actual start up of the vehicle. No matter what the
size of the asset, only a few minutes were needed for the removal
of the cover. Removal of any other VCI product was not necessary.
The assets were ready for immediate utilization or war readiness.
All vehicles and equipment were placed in high usage areas to evaluate
the effects if any of the products to the operation of the asset.
Benefits identified with VCI systems
The benefits derived and identified in the evaluation
of VCI systems in deep storage and preservation were quickly noted
throughout the application process and upon the completion of the
test. Ease of application and the ability for military personnel
to be proficient in the application of the VCI products was the
first benefit identified to be advantageous. The efficiency of the
application and removal created further economic advantages. Although
the cost of the products was competitive to current products being
used, this was not the most critical factor in the evaluation.
During the term of the test, exercising of the
equipment was not needed. Of the few repairs identified after breakout,
none were as a result of the VCI preservation system. This in itself
is critical due to the decreased need for man-hour labor for exercising,
repair, parts and maintenance. Normal costs attributed to labor
and parts is substantially less and further analysis will be given
to determine overall savings.
The reduction of breakout time in comparison to
other preservation programs was considered to be also a very significant
factor. The enhancement of immediate war readiness makes the VCI
deep storage and preservation system the best alternative if deep
storage is considered for any vehicle or piece of equipment. Briefing
after briefing regarding this system creates a great deal of interest.
A final executive report will be made and presented to the Air Staff
at the Pentagon.
The environmentally friendly products/systems are
advantageous to worker safety as well. The USAF as other military
branches has taken the initiative to replace hazardous products
as well as cumbersome work practices.
The benefits of this innovative VCI technology
have been quoted as being revolutionary in the storage of vehicles
and equipment storage. The technology has been proven commercially
and industrially in all industries. The savings have been determined
to outweigh the costs and any risks involved in the testing.
Comparing both processes, the VCI products were
shown to be the overall system that can provide all of the above
benefits with superior corrosion protection even in extreme atmospheric
conditions. The consideration of reduced manpower stands out and
has been quoted as "revolutionary" in the way assets can
The entire VCI storage process/system approach
was very quick and the procedures for placing vehicles into storage
are very simple. Basically, after one day of training, the USAF
team was well versed and confident. Moreover, the VCI products were
very users friendly and easy to apply. Preparation was not labor
USAF expectations after exercising the vehicles
in the 90 days that followed the final depreservation, are that
the VCI process and materials would be a great asset to incorporate
into the USAF War Readiness Materials (WRM) vehicle storage program.
The amount of time to prepare and break out the vehicles and equipment
combined with corrosion protection given should greatly contribute
to war fighting capabilities.
- B. A. Miksic, "Temporary Protection, Lay-up and Mothballing",
1988 Handbook, Manual.
- K. L. Vasanth and C.M. Dacres, "Vapor Phase Inhibitors
for Navy Applications", CORROSION 97, paper no.179 (Houston,
Texas, NACE International, 1997).
- K. L. Vasanth, "Corrosion Inhibition in Naval Vessels",
CORROSION 96, paper no.233, (Denver, CO, NACE International, 1996).
- B. A. Miksic, "Volatile Corrosion Inhibitors Find a New
Home", Sept. 1977, Material Engineering Forum, Pages 14-18.
VCI PERFORMANCE IN INDUSTRIAL AND MARINE ATMOSPHERES
Corrosion rate in Mils/Year
Protected with VCI
1000, 3000, 5000,6000 series
HSLA (high-strength, low alloy
Stainless Steels: 410
301, 316, 321
- Dezincification 2. Immune to attack; no pitting or weight loss
observed 3. Pitting 4. Pitting reduced 5. Staining 6. No Staining
7. Free from pitting and weight loss
LIST OF MILITARY SPECIFICATIONS
Cleaning Compound, Aerospace Equipment
Corrosion Preventive Compound, Solvent Cutback,
Lubricating oil, Contact and Volatile Corrosion
Corrosion Preventive Compound, Cold Application
Corrosion Preventive Compound, Water displacing,
Ultra thin film
Inhibitors, Corrosion, Volatile, Crystalline
Static dissipative material
Barrier materials, Transparent, Flexible,
Sealable, VCI treated
Bags, Transparent, Flexible, Heat seal, VCI
Bags, Barrier with Vapor Corrosion Inhibitor
Application in Man Hours
VCI Product Cost
Average of 120 vehicles
40K Air Cargo Loader
Notes: 1. Many other types of vehicles were included;
these were chosen to illustrate the differences in cost. 2. Application
included the entire process from initial cleaning, coating and on
to the last step.
Figure 1. 60K Air cargo loader covered with VCI
High UV, Flame Retardant Shrink film.