Skid Resistance Tester

Skid Resistance Tester
BPN measurments taken uder
ASTM E303 for Measuring Surface Frictional Properties

New Anti-Climb Paint

Long-wearing eco-friendly formula drastically reduces scalability of vertical surfaces.


In 2014 the US Department of State, Bureau of Diplomatic Security (DS) in conjunction Sandia National Labs (SNL) evaluated the effectivness of commerically available anti-climb paint and other coatings. This evaluation found that these products degraded quickly and provided no benefit after about a week of outdoor exposure. DS required a product that would be much more environmentally durable. In November 2016, DS initiated a program with a Private Research Partner (PRP) to develop an anti-climb coating. DS wanted to develop a commercially available product suitable for applying to a variety of surfaces (metal, concrete, stucco, etc.) in order to increase delay time required to scale a vertical surface. Both the SNL and PRP programs utilized a “skid resistance tester” to objectively measure relative friction forces. A skid resistance tester’s output measures in British Pendulum Number (BPN) units, with a lower number being an indication of reduced friction.



After 6 Years of Simulated UV Exposure
Under ASTM D4587 “Weatherometer” testing

PRP developed the concept of mixing layered structured mineral filler (LSMFs) into a binder – the LMSF particles slough off naturally and provide a built-in anti-graffiti benefit as well. LSMFs have excellent slip capability along the sheet layer surface. PRP developed a very slick “dark variant” matte paint with graphite mineral powder. Color options for the dark variant are limited to black and dark gray. PRP also developed a “light variant” paint with talc mineral powder. It is slightly less effective and more complicated to produce but capable of accommodating any project / customer- required tint. Both variants are easy to apply and touch up with a brush, roller or sprayer, and are commercially available in bulk quantities.

Friction reduction measurements

Bare, Untreated Substrate Coated Substrate
Metal (galvanized) 74 BPN
  • 20 BPN for dark variant, a 73% reduction
  • 27 BPN for light variant, a 64% reduction
CMU Block (Cementous) 81 BPN
  • 29 BPN for dark variant, a 64% reduction
  • 31 BPN for light variant, a 62% reduction

Graphite (left, gray) and Talc (right, white)
Under a microscope

The paint developed by PRP has a lower BPN than Teflon™. Teflon™ measures 34 BPN, but metal coated with this dark variant paint has a BPN as low as 20 BPN.

Environmental and Quality Testing

The table below lists the environmental testing conducted by PRP during the development of this paint formulation.

Test Standard Details
Panels Left Outdoors N/A
  • 0-203+ days of exposure
Blowing Rain MIL-STD-810 Method 506.5
  • 40 mph (64 kph) rain at 45 degrees for 4 hours
Blowing Wind Modified MIL-STD-810 Method 506.5
  • 40 mph (64 kph) wind at 0 degrees for 4 hours
Blowing Sand MIL-STD-810 Method 510.5
  • 40 mph (64 kph) wind at 0 degrees for 12 hours
UV Light ASTM D4587
  • Cyclic exposure of 4 hours at UVA-340nm at 122°F (50°C), then 4 hours condensation exposure
Low Humidity MIL-STD-810 Method 507.5
  • <10% Relative Humidity (RH), Relative/Room Temperature (RT) at 72°F (22°C), for 45 days
High Humidity MIL-STD-810 Method 507.5
  • 95% Relative Humidity (RH), 120°F (49°C), for 45 days
Low Temperature MIL-STD-810 Method 502.5
  • 0°F (-18°C) for 45 days
High Temperature MIL-STD-810 Method 501.5
  • 120°F (49°C) for 45 days
Thermal Cycling ASTM D6944
  • 30 cycles of 0-120°F (-18-49°C)
Shelf Life, Freeze/Thaw ASTM D2243
  • Thermal cycling of paint in can, 5 cycles of 0-75°F (-18-24°C)
Shelf Life, RT/Hot N/A
  • Can sitting at room temperature and 90°F (32.2°C) for 6 months
Flammability ASTM D1321
  • Up to 65 kW/m
Volatile Organic Content (VOC) EPA Method 24
  • <0.5 Lb./Gal(60 Gm/Lt)

During environmental testing it was discovered that the paint actually gets more slippery with time. The paint is also non-corrosive, non-toxic, and non-staining to passersby.


In February 2019, PRP partnered with Watson Coatings, Inc (St. Louis, MO) for pilot scale production and formula optimization (i.e. color fastness, rust inhibition, etc.). Watson Coatings manufactures specialized, high performance water-based and water-reducible coatings for the Architectural, Industrial and Structural Coatings Markets. Watson Coatings is the manufacturer of the acrylic-based binder that was used for this testing. During testing it was found that using this binder created a better paint than using other commercially available binders. Both the light and dark paint formulations are being finalized and will be available for purchase directly from Watson Coatings under the name Watson Climb-Guard™. The paint can be shipped as non-hazardous. Directions supplied with the paint for surface prep and application must be followed to achieve the desired performance.

Product Data Sheet
Safety Data Sheet
Color Chart

Gary Watson
Rick Noles
John Markowski

325 Paul Ave St. Louis, MO 63135
(314) 521-2000

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