
Introduction
Harpic is the brand name of a toilet bowl cleaner. It has been found to be effective in removing  stains  on tiles, lavatories and  bath etc. It is highly recommended that you put on gloves, protect your eyes  with goggles to avoid spillage from highly concentrated acid. Be very careful, keep chemicals far away from children. Most of the chemicals here are very corrosive.
Lets get going
Ingredients                           Â
7.5 liters water
125 Nitrosol
250g Caustic Soda
250 Soda Ash
500g Texapon
500ml Sulphonic Acid
1 litre HCl
Deep blue Colour
Perfume (optional)
Before Production
Dissolve nitrosol in 5 litres of water
Dissolve caustic soda in 1 litre of water in another container
Dissolve soda ash in 1.5 litres of water of water in a separate container
Mix texapon and sulphonic acid together
Add Hcl to  1 litre of  waterPlease do not turn water to HCl, rather turn HCl to water. Failure to do as instructed may lead to spillage of concentrated acid on you.
Method/ Procedure
Mix Caustic Soda solution with Nitrosol solution and stir vigorously
Add soda ash solution to the above and continue stirring
Add the mixture of texapon and sulphonic acid to the above
Add HCl solution to the above carefully and slowly ( please be real careful with this). Keep your face away from the mixture.
Add Colour and perfume
Stir and package
Altogether should about 10 litres. You can also dilute it if it is too thick.