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Metal treatment against rust

There are several ways to clean metal from rust

The mechanical method involves mechanical action on the surface by hand or with special equipment. Sandblasting is the most effective method for mechanically removing rust.

rust treatment

The chemical method consists of chemical action on the metal. Acids are used: phosphoric, sulfuric and hydrochloric, or compositions based on them. A corrosion inhibitor is also added (for example hexamine).

A 5 percent aqueous solution of hydrochloric or sulfuric acid copes reasonably well with rust removal. It should be remembered that a corrosion inhibitor must always be introduced into the solution. Otherwise these acids corrode the metal surface itself along with the rust.

That is why a solution of Orthophosphoric acid is most often used. A 15 percent aqueous solution is taken (sometimes a higher concentration is used, up to 30 percent). Tartaric acid or butyl alcohol is sometimes added to the acid, which improves the effectiveness of the treatment. When phosphoric acid acts on metal, a protective coating forms — iron orthophosphate.

Another method used is treating rust with a solution of lactic acid (lactate, 2-hydroxypropanoic acid) combined with vaseline oil. The basis of the process is that under the action of the acid the rust turns into a metal salt that is readily soluble in oil. Once the process is complete, the treated metal simply needs to be wiped down.

Corrosion prevention

To prevent the formation of corrosion, the metal surface is coated with protective compositions and specialised multicomponent paints. The protective effect is based on the property of repelling water from the metal surface. Paraffins or fatty acids, for example Oleic acid, can be used as a simple remedy.

To buy Orthophosphoric acid 73% call us at (495)133-02-40, (495)407-17-86.

Send a request to order@chimko.com or use the feedback form.

Overview article on corrosion inhibitors.
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