International Lead Zinc Research Organization, Inc.

Noel Dreulle

Michel Longuepee

Solution and procedure of depositing a coating on the surfaces of zinc-coated ferrous metal parts which protects against corrosion in the presence of water. The solution is made up by adding to water, perliter of final solution, of 1 to 40 grams of sodium metasilicate, 14 to 40 milliliters of phosphoric acid, specific gravity 1.71, from 1 to 40 grams of sodium nitrate, from 10 to 50 grams of anhydrous zinc chloride and the pH is adjusted to a value between 2.3 and 3.8. Preferably nickel chloride is added. For use, the solution is heated to a temperature ranging from 15.degree. to 75.degree. C and brought into contact with the parts to be treated for a period from 20 to 72 hours. The deposit is continuous, hard, resistant to shocks and abrasion and imparts an efficient and lasting protection to galvanized parts in corrosive waters. The invention is useful for the protection of piping in the building industry.

Solution and procedure for depositing a protective precoating on

Solution and procedure of depositing a coating on the surfaces of zinc-coated ferrous metal parts which protects against corrosion in the presence of water. The solution is made up by adding to water, per liter of final solution, of 1 to 40 grams of sodium metasilicate, 14 to 40 milliliters of phosphoric acid, density 1.71 g/ml, from 1 to 40 grams of sodium nitrate, from 10 to 50 grams of anhydrous zinc chloride and the pH is adjusted to a value between 2.3 and 3.8. Preferably nickel chloride is added. For use, the solution is heated to a temperature ranging from 15.degree. to 75.degree. C and brought into contact with the parts to be treated for a period from 20 to 72 hours. The deposit is continuous, hard, resistant to shocks and abrasion and imparts an efficient and lasting protection to galvanized parts in corrosive waters. The invention is useful for the protection of piping in the building industry.

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Auby-lez-Douai, France

Noel Dreulle