Mould
A teak wood mould should be prepared for this purpose. It should be cleaned and oiled after every operation. After manufacturing 100 Nos. of grills, the mould should be repainted with oil paint. Good maintenance of the moulds will increase the life and the number of grills manufactured.
Raw material
· Cement
· Grit
· 12 mm metal
· Sand
· Steel
Mix these ingredients in equal proportions i.e 1:1:1:1. Normally, 5 Nos. of medium sized grills can be manufactured in one cement bag.
Reinforcement
6 mm or 8 mm and steel cut-pieces can be used as reinforcement. This reinforcement should be tied properly with the help of a binding wire, before placing it in the mould.
Procedure
- Measure all the ingredients in proportion. Mix them dry and then add sufficient water for a proper consistency.
- Take an oiled mould and fill half the thickness of the mould with the mix.
- Place reinforcement which is tied properly.
- Pour the remaining mix for full thickness.
- Add dry cement on the top to get a proper finish.
- Wait for about half an hour for the initial setting.
- After sufficient setting, lift the mould slowly to release the grill. Then, turn the mould downwards, slowly and evenly, so that the grill slides on the ground.
- Apply cement slurry with a brush to this ready grill so that fine holes, bubble deformation etc are filled up.
- For the final setting, leave this grill undisturbed for 24 hours.
- Put this ready grill in the curing pond for a minimum of 15 days.
Note : If the grills are manufactured on site, it saves almost 25 % of the cost while providing better quality.
