Fun facts about pitch and the pitfalls of ignorance

The various properties of polishing pitches have different advantages and are selected according to the type of work intended. It is important to check pitch properties before a pitch lap is poured; to ensure that the final polishing lap properties will be as desired. A simple penetrometer test is utilized as a quality control tool for measuring the hardness (viscosity) of various types of pitch as received from the manufacturer. Only a small sample, 20 grams, is needed for this test. Another simple method for determining pitch quality is the measurement of the softening point. A description of this method and typical results will be described. Lastly, the 'tackiness' of pitch and its importance will be discussed.