Effective ways to remove rust from metal before painting

foto21442-1Carrying out rust treatment before painting the metal is a necessary part of the repair work.

The purpose of such an impact is not only to return an attractive appearance to a metal product, but also to maintain functionality, as well as extend its service life.

How to treat metal from rust before painting it will be discussed in the article.

Rusty metal surface treatments

foto21442-2The choice of rust treatment method depends on the degree of corrosion and the type of item itself. It is also necessary to consider what metal care products are available for use and are in stock.

The most common processing methods include:

  1. Chemical.
  2. Mechanical.
  3. Thermal. It is carried out using a burner.

Rust cannot be removed by rinsing off with plain water. For this purpose, targeted complete processing is required.

All the most useful and important about the methods and methods of removing rust will be found in this section.

Thermal

The thermal method is rarely used... The use of an oxygen-acetylene torch allows for good removal of mill scale, but does not completely remove rust.

The use of burners must be carried out under suitable conditions. Despite the high invasiveness of the method, its effectiveness is inferior to chemical treatment.

Mechanical

foto21442-3Physical impact on rust is designed to remove the loose top layer of material. This can be done in several ways:

  • manually (using a brush with metal bristles and scrapers);
  • with the use of a grinding machine or a special machine.

In addition to those that are available at home, in industrial plants for rust treatment serious devices are also used with the use of special equipment:

  • shot blasting;
  • water sandblasting;
  • sandblasting.

The best result is obtained by a combination of abrasive and chemical action.

Chemical

Chemical processing is carried out using home-made products and purchased, ready-to-use preparations. Besides, large metal surfaces are also subjected to special influences to preserve and protect the material:

  • compound with organic additives, providing bluing;
  • cementation is a chemical reaction with carbon;
  • nitriding, etc.
The chemical method allows you to remove rust by a chemical reaction with the use of substances active to the products of corrosion.

Homemade treatments include:

  • preparation of the material;
  • exposure to a chemical;
  • wash off.

The type of chemical attack should take into account the degree of damage to the metal.

How to remove plaque with folk remedies?

Increasing the effectiveness of the method of exposure gives a combination of chemical treatment and mechanical action... Homemade recipes are based on readily available remedies that may already be in the household. Their main advantage is their cheapness and availability.

As a rule, the choice in favor of folk recipes is made with slight corrosion. Dealing with it is often not difficult.

Coca-Cola

foto21442-4The use of Coca-Cola in the household allows cleaning of various surfaces. One of the popular recipes is to use the beverage to remove rust.

For, so that the phosphoric acid in the drink works, you can use a rag soaked in Cola... A rag is moistened liberally in the drink and applied to the surface that needs to be cleaned from corrosion.

This recipe is suitable when the rust has not penetrated deep into the metal, since the concentration of phosphoric acid in Coca-Cola is low. The exposure time should be at least several hours, preferably a day.

But with serious damage to the metal, this method is ineffective... At the end of the exposure, Cola is washed off with water, and the surface is wiped dry. When using Cola, it is sufficient to use only rubber gloves as a means of protection. Read more about the use of Coca-Cola against rust. here.

Acids

Various acids have proven themselves well in the fight against rust:

Lemon

One of the easiest recipes to deal with rust is to use citric acid.

To do this, the acid powder is diluted so that a very concentrated solution is obtained, with all the grains completely dissolved.

The tool can be used in two ways:

  • apply a sponge generously to the affected areas of the metal;
  • soak a rag with the solution and apply to the rusted areas.

The last of the options presented is more effective, but even this method will not eliminate serious corrosion.

The duration of the composition is at least an hour... After that, the metal should be cleaned with a stiff brush, and the remains should be washed off. Read more about the use of citric acid in the fight against rust. here.

Acetic

foto21442-5Vinegar also removes rust from mild corrosive processes. Undiluted vinegar is used for exposure.

If the rusted objects are small, they can be folded into a container and simply poured... For large metal objects, make sure the scraped surface is in contact with the vinegar.

After exposure to acetic acid, the surface is finished by mechanical scrubbing and rinsing off the vinegar residues.

Before directly painting, the metal must be primed. Learn more about using vinegar to combat metal corrosion in this articles.

Sorrel

Oxalic acid is a drug that comes in powder form... This remedy gives good results, but requires very careful use, as it is poison. Use may only be carried out with all the necessary protective measures.

Before using the acid, the metal surface should be prepared - washed with soap and dried. The solution for processing is prepared by diluting 6 tsp. acid in 300 ml. water.

Order of use:

  1. Apply the solution generously with a brush.
  2. Leave for 30-40 minutes.
  3. Remove loose rust.
  4. Wash off the rest of the product with water.

Oxalic acid is suitable for advanced cases and large surface areas.

Orthophosphoric

foto21442-6Phosphoric acid is a commonly used component of off-the-shelf rust converters.

This substance is highly effective and can be used even in advanced cases.

To prepare the metal for painting, an acid concentration of 15-20% is required. The exposure to phosphoric acid should not be prolonged - just 5 minutes is enough. After that, you can walk over the surface with a brush.

All work must be carried out with adequate ventilation and protective equipment. More about the use of phosphoric acid - here.

How to clean with special compounds?

Commercially available anti-corrosion treatments are highly formulated with high concentrations of active ingredients... These drugs will help in cases where there is neglected corrosion with serious damage to the metal, covering a significant area or the surface of serious equipment, for example, a car, is damaged.

Means can be both acidic and acid-free. In addition to the main active ingredient, the finished products include corrosion inhibitors, thickeners and other additional components.

Before using the transducer, the surface must be prepared:

  • eliminate pollution;
  • clean off the loose layer of rust;
  • degrease the surface.

Hi-Gear Rust Treatment

Hi-Gear is a rust converter that will cope with even advanced corrosion, as it penetrates even deep layers of material. The drug is applied by spraying. As a result of a chemical reaction, rust is removed, and a polymer protective compound is formed on the surface.

Using Hi-Gear requires care, since the composition is capable of reacting not only with corrosion products, but also with paintwork. After exposure to the converter, it must be washed off using solvents for this alcohol.

Despite the high price for a bottle, the purchase can be considered profitable, since the expense of the product is very economical. Packing price - about 700 rubles.

foto21442-7

Fenom

A hairdryer is a rust converter, which is often chosen by motorists. The product spreads well on the surface and creates a dense polymer layer. The drug is a reliable tool that prevents the recurrence of corrosion at the treatment site for many years.

The hairdryer is produced in a compact black package, it is a white liquid... Due to the small volume of the product in one bottle, several bottles may be needed to process a large area of ​​metal.

One of the main disadvantages is the small volume. When purchasing multiple vials, the processing cost increases significantly.

Pros of using:

  • efficiency;
  • affordable price for 1 bottle;
  • a protective layer is created;
  • quick and easy application - brush application;
  • high-quality metal processing through complex exposure.

The price of a small bottle is about 150 rubles.

foto21442-8

Kudo KV-70005

Kudo is a structural modifier that effectively removes rust due to the incorporation of acids. It can be used to repair small areas of corrosion. The product is packaged in small bottles, it is conveniently applied with a brush that comes with the kit.

Due to the fact that the composition of Kudo does not react with varnishes and paints, it can be safely used on equipment, including bodywork. After application and reaction, a protective film with zinc is created on the metal surface.

The price for 15 ml is 120 rubles.

foto21442-9

Recommendations

To make the processing of rust on metal as productive as possible, you must adhere to the following recommendations:

  1. The corrosion process starts from the most vulnerable areas.It is possible to prevent its spread by stripping and creating a protective coating.
  2. When carrying out rust removal work, personal protective equipment must be used.
  3. When working with purchased products, rust converters, you must first study the instructions for the selected preparation, and strictly follow it.
  4. Even expensive rust converters are not able to repair metal if it has very significant damage, for example, through corrosion.
  5. Preventing rust formation will help keep metal products in good condition.
  6. The most reliable metal protection is its galvanization. The use of zinc-containing agents prevents corrosion.
Metals with no alloying elements are more prone to corrosion.

Related videos

How to get rid of rust on metal, the video will tell:

Conclusion

Preparing a rusted surface for painting is a prerequisite that will allow the coating to adhere well. This requires an integrated approach and complete elimination of corrosion.

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