In order to make the sand mold (core) qualified, the defects of the sand mold (core) should be repaired with various shape tools. Commonly used repair tools are as follows.
1 trowel: Also known as scraper, it is generally made of tool steel, with flat head, round head and pointed head. The handle is made of hardwood. It is used to repair the large plane of the sand mold (core), excavate the pouring riser, cut the large groove and beat the nail into the sand mold when the sand mold is inserted.
2 lifting hook: Also called sand hook; made of tool steel. It is used to repair the deep and narrow bottom and sidewall of sand mold (core) and to put forward the loose sand falling in the sand mold.
3 bamboo stem: It is also called a bamboo stem or a flat rod, which is used to trim the inner wall of the vertical arc and its bottom surface.
4 flange stem: Also known as smooth groove trowel blade, made of steel or bronze. It is used for repairing the deep and narrow bottom of sand mold (core) and the narrow edge of flange at both ends of pipe.
5 shaped trowel: It is made of steel or cast iron with different shapes, which are often determined by the shape of the surface repaired in actual production. It is used to trim the internal and external fillets, square angles and arc surfaces on the troweled sand mold (core).
6 press spoon: Most of them are made of steel, one end is curved, the other end is flat, and the inclination of spoon handle is 30 °. It is used for repairing the small plane of sand mold (core) and opening the small gate.
7 double head copper spoon: Also known as autumn leaf, it is a copper tool with spoon shaped ends. Used to trim surfaces or narrow recesses.