With the materials that are available all over the country, Industrial Technology and Development Institute fabricated blocks which need no firing. The block has a square face and grooved sides which allow adequate surface for bonding. It measures 8″x8″x6″. The provinces of La Union, Bulacan, Batangas, Quezon, Bohol and Negros Occidental have reserves of all the 4 non-metallic ores herein used. Clay and limestone may be found in almost all the regions while sufficient amount of sand and gravel occur in Regions III, IV, VI and X.
Wire mesh screen
Wooden measuring box
1. Crush the lumps of clay into smaller pieces with a pickaxe. With the use of a wire mesh screen, remove impurities, such as stones, roots, twigs, etc.
2. Sift the lime and the sand separately to remove the bigger particles.
3. Mix thoroughly five (5) boxes of clay, two (2) of lime and two (2) of sand.
4. Add water slowly until the right consistency is reached. The mixture should neither be too wet nor too dry so that when molded, the block will maintain its shape.
5. Press the mixture into a wooden mold until all spaces are filled up and scrape off the excess.
6. Remove the mold and allow the formed block to stand in the shade for 3 days. Then sun-dry for another 3 days.
Source: Ceramics Research Division ITDI (DOST)