'Mood paint' lets you know if ammo got too hot



Thermal indicating paints being developed at Picatinny can detect a range of temperature bands and display a distinct color for each range. (Army photo)

Engineers are working on a color-changing paint that indicates whether ammunition has been stored at extreme temperatures. Such temperatures can compromise performance and pose a safety risk for the soldier.

Thermal indicating paint works like a mood ring – the longer the ammo has been in an extreme environment, the greater the color changes. Thermochromic polymers, which change the wavelength of light when exposed to different temperatures, are the key.

“We have formulas that change color within the designated temperature ranges, but our biggest challenge is maintaining long-term stability of a coating,” James Zunino, project officer/materials engineer of the Armament Research, Development and Engineering Center, said in a release. “We have to develop a paint that will survive in military operating conditions, including harsh temperatures and wind blasts.”

Failures caused by thermal exposure have occurred in Operation Desert Storm and recent conflicts in Iraq and Afghanistan, the release said, without specifying the kinds or locations of failures. Auto-ignition can occur in propelling charges exposed to high temperatures for extended periods. Elevated gun pressure and weapon failure can occur if an overheated propellant is fired.

Research shows that temperatures inside munitions’ containers in the Middle East can exceed 190 degrees. The new paint will identify four heat ranges: 145 to 164 degrees, 165 to 184 degrees, 185 to 200 degrees and above 200 degrees.

The 30mm High Explosive round will likely be the first tested due to its low cost, the release said.

A worthy endeavor, indeed.  If only they could figure out a way to apply this to the first sergeant’s ACUs.


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A Navy brat who spent eight years in the Marines (two years aboard the carrier Independence). Worked in journalism in Eastern North Carolina through the latter part of the 90s, then became editor of Air Force Times in 2000. Stayed there five years, then took a break to finish some school. Now back in the game with Navy Times.

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