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How do I descale the engine cooling system?
Seawater, like soft water of varying degrees of hardness, can cause scaling. Depending on the contact temperature in the circuit, the following phenomena occur:
- Below a temperature of 100°C, calcium bicabornate precipitates.
- Above 100°C, calcium sulfate precipitates are added.
What's more, with a cooling system that circulates seawater, there's a risk of corrosion due to deposits of marine micro-organisms, algae...
It is therefore strongly recommended to descale once a year its cooling circuit. Over time, laitance and limescale deposits will clog temperature exchangers, condensers, evaporators and cooling circuits.
The best way to descale your unit is to drain all the water from the system. Then rinse with fresh water to remove the chlorides found in seawater. Then use MATT CHEM MARINE D.K.L.4 thermal descaler with built-in indicator.
D.K.L.4 descaler completely removes all laitance and limescale deposits clogging cooling circuits, exchangers, condensers, etc. D.K.L.4 descaler is gentle on ferrous metals and light alloys, as it contains corrosion inhibitors. It does not damage plastics or rubber. D.K.L.4 descaler turns yellow on contact with calcium tartar, agglomerates and organo-mineral deposits. Its built-in indicator shows when descaling is complete.
By dissolving limescale, D.K.L.4 restores cooling circuits' nominal capacities and characteristics.
To descale an inboard motor, use 3 to 5 liters of D.K.L.4 and 2 liters for an outboard motor. Descaling is performed using a solution of the product circulated in a closed circuit in the motor's seawater system.
phase 1: START-UP
Dilute 3% D.K.L.4 in fresh water (i.e. 3 liters per 100 liters of water). The solution is red in color. Run the engine for 15 minutes to a maximum of 30 minutes, monitoring engine temperature. As the solution becomes loaded with limescale, its color will turn yellow. Do not drain the circuit.
2nd phase: CONTROL
After 30 minutes, add D.K.L.4 to the yellow solution, until the color turns red. When the solution remains red, descaling is complete. Drain and rinse the circuit. The procedure is the same for descaling an outboard motor.
To descale parts, dilute 1 liter of product in 5 liters of water. Immerse heavily scaled parts in a solution of D.K.L.4, preferably hot. The reaction time will vary (several hours) depending on the degree of soiling. Then rinse.
In both cases, 1 to 2 minutes of rinsing is sufficient.
