Calcium and lime build up as little as 1/64” thick in your heat exchanger or oil cooler will effect the heat transfer from your engine’s antifreeze to the raw water flowing through the heat exchanger. This mild buildup often results in engines running hotter than normal at higher RPMs.

Keep in mind that in a typical marine engine, the raw water runs through and oil cooler, transmission oil cooler, engine heat exchanger, exhaust manifold, muffler then exits the boat through the exhaust outlet. With Sea Flush, you’re able to introduce a liquid marine growth remover, such as Barnacle Buster, to the critical cooling points without removing parts or even hoses. We suggest descaling periodically as part of a preventive maintenance plan. It’s easier and cheaper to descale with the Sea Flush pickling method, no hoses or components need to be removed.

Common Misbeliefs:  

“I see normal water flow from the exhaust outlet, my raw-water system can’t need to be cleaned.” False: just because water is flowing through a cooler doesn’t mean it’s absorbing the engine’s heat. Build up from calcium and lime acts as an insulator on the copper tubes in the coolers. Seeing reduced water flow from the exhaust is a sign of a major blockage and a more expensive fix is likely needed.  

“It’s safe to clean heat exchangers and coolers with muriatic acid.” Muriatic acid is not only effective in descaling a heat exchanger, it also does a number on your skin and lungs. To be safe, you need a proper respirator and gloves that are rated for use with acid. We simply can’t endorse using such a toxic chemical in an enclosed area like an engine room. Aside from the potential harm to you, muriatic acid also attacks the solder which seals the tubes in your heat exchanger/oil cooler. Because of the potential for personal injury, damage to engine parts and the environmental impact, we don’t think it’s safe to clean with muriatic acid. We suggest using a safer scale remover, like Barnacle Buster, to pickle and clean your raw water system.