Hydro Find Paste is a water detecting green colored smooth paste.
It is required to indicate the presence and level of any water layer in the fuel tank by a clearly visible change of colour from green to red.
Apply some of the well-mixed paste to the clean brass strip to from a thin coating extending for approximately 10 cm from on end. Fill the jar to a depth of 5 cm with water. Sufficient diesel fuel, 47 cetane, 20 pour to specification DEF—2402A to produce an upper layer extending to within 5 cm of the top of the jar.
Dip the coated end of the brass strip vertically into the jar and support the stripe so that the paste is immersed in the fuel layer for 1 minute. Lower the strip to rest on the bottom of jar, nothing the speed and uniformity of development of red colour on the portion of the paste coating immersed in the water layer.
After 2 minutes note the accuracy of the indication of the water level and raise the strip again so that the pasties immersed only in the fuel layer. Hold the strip in this position for 1 minute.
Withdraw the strip completely from the jar and after a further interval of 1 minute examine the paste coating for a sharp line of demarcation between the green and red coloured areas.