In 2001, the trucking industry experienced some major problems when increased pollution controls raised under-hood temperatures and caused failures in big rigs, specifically in the tractor-trailers’ turbocharger systems. Without the extra boost from the turbochargers, these trucks had little power and were breaking down on roadsides all across the U.S.
The culprit turned out to be the charged air coolers (CAGs). Much like car radiators, CAGs are used to cool the turbo units. The CAG base has soldered fins that look and function exactly like automobile radiators, and these were leaking from micro-holes that were caused by displaced solder.
A means to quickly seal the CAGs was immediately needed to get the trucks back on the road. Because CAGs are constructed from a magnesium aluminum alloy with a zinc-rich surface coating, they presented a difficult substrate for bonding. The zinc easily flaked off and acted like a release agent, hindering any potential sealer.
The CAG manufacturer asked Silicone Solutions for help. Silicones were the only materials considered due to the long-term service exposure to temperatures over 300°F. In one week, Silicone Solutions responded with SS-1801, Radiator Coating Liquid RTV, which has the ability to seep into the CAG’s several sub-layers and efficiently bond to, seal, and coat the base of the CAG around the fin mating areas.