Sometimes it is necessary to remove paint from metal surfaces. There are several ways to remove old paint.
Features of the
There are three known methods for removing old paint from a metal surface:
- Mechanical - processing is carried out by sandblasting machine or manually using sandpaper. May damage metal.
- Burning out - heating the metal to high temperatures, due to which the paint itself lags behind. This method creates a fire hazard and surface damage.
- Chemical - the use of special compounds that corrode paint in a short period of time.
The chemical method of removing the old coating is the most demanded and common, because removers only destroy paint without affecting the surface itself. The formulations are easy to use and are presented in a wide range.
Advantages and disadvantages
Chemical paint removers have many advantages over other cleaning methods. These include the resistance of the surface to the effects of chemicals in their composition (as opposed to mechanical cleaning methods) and ease of application and cleaning of paint and varnish products.
Paint strippers work fairly quickly. It depends on the type of purifier, the number of layers of the old coating and the air temperature. On average, it takes from 20 minutes to 2 hours to dissolve one layer … There is no need to apply great efforts to remove the dissolved old paint - the old coating can be easily removed with a spatula.
Often, a washing agent (remover) dissolves not only unnecessary coating, but also cleans the metal from corrosion, which saves time and eliminates additional steps.
Cons of metal washes:
- If the paint is thick, it is necessary to reapply the paint remover several times.
- Sometimes grease remains on the surface after using the remover. This is due to the specific composition of the wash. To get rid of these stains, after cleaning the surface, you must treat it with a degreasing agent.
After applying the cleaning agent, after a while, the paint softens, flakes off and begins to swell. The coating loses its strength and density, and the adhesion capacity is significantly reduced. This means that the solvent has taken effect.
After the time indicated on the container with the remover has passed, you can start removing the paint with a spatula. The coating can be removed easily - under the influence of a cleaning agent, it itself lags behind the surface.
Varieties and composition
Washes are divided according to the type of paint to be removed:
- Universal - suitable for various surfaces: metal, concrete, wood. They have a high shelf life and are able to dissolve even powder coatings, but are useless for water dispersion, acrylate and latex paints.
- For oil coatings … Contains organic baking powder, thickener and solvent. Shake the mixture before use.
- For water-based coatings … The mixture is almost identical in composition with water dispersion removers. It is advisable not to purchase liquid with hydrochloric acid in the composition.
- Express wash … They have a fast exposure time - just a few minutes.
- For powder paints … Due to the high strength of powder coatings, stronger and more toxic washes are used.
Universal products have a lower price and are suitable for almost all types of paints, but it is recommended to use them in extreme cases, because they often do not completely dissolve the coating immediately, and thus their consumption increases.
Since the flushing liquid works only until it evaporates completely, some washes are added to wax or paraffin. These materials slow down the evaporation process, thereby improving the effect of the wash … But they have a drawback: paraffin reduces the adhesion ability of the metal.
If you do not completely clean the surface of its traces, then the new coating will not be able to adhere well to the surface.
Sometimes just water and a cleaning agent are not enough to remove paraffin or wax. In such cases, acetone or another organic solvent is used. On the modern market, you can find paraffin-free cleaning agents, more modern evaporation inhibitors are added to their composition. Such products do not require subsequent special cleaning of the surface.
By the type of consistency, the following types of washes are distinguished:
- in the form of a gel;
- water soluble powders;
The advantage gel solvents is the possibility of their application on a vertical surface and even on ceilings due to their viscosity.
With sprays it is necessary to be careful: it is necessary to spray the composition at a distance of 25-30 cm from the surface and in an upright position, at a great distance from sources of fire (do not differ in fire resistance) and use closed clothing and goggles.
Paste removers well suited for profiled surfaces because they penetrate perfectly into all recesses that, for example, a liquid solvent cannot cope with. Liquid formulations are best applied to flat surfaces.
The coating remover can be applied with a brush if the surface has uneven texture and fine detail. For a large surface with an even texture, it is preferable to use a roller. With a spray gun, you can apply a wash in a liquid state.
By the types of components in the composition of the washes are divided into the following categories:
- acidic (hydrochloric acid is often present);
- organic (characterized by the absence of alkalis and acids in the composition).
Basically, acids or alkalis are not terrible for metal, but nevertheless, for a successful result, it is better to look closely at washes with organic substances.
Popular removers include:
- Aerosol cleaner ABRO PR-600 … It is safe and easily washed off with water, does not contain alkalis. The softening time of the paint is approximately 10-20 minutes. Suitable for cleaning acrylic, epoxy, polyurethane coatings.
- Washing off "SP-7" … The composition is based on organic components, it is also safe. Suitable for removing oil, acrylic, epoxy and alkyd coatings. This Russian-made remover has all the necessary advantages: fire resistance, rapid paint destruction, penetration into deep layers of the coating, removal of corrosion traces. It is used for both horizontal and vertical surfaces.
The amount of liquid required for removing paint and varnish coatings depends on the area of the surface to be treated, its condition (whether there are traces of corrosion), the type of cleaning agent, and the thickness of the old coating. The thicker the old paint, the more times you will have to treat the metal surface with a remover, which means that the consumption of funds will be greater. Also for removing the oil layer of paint will require more liquid than other types of paints.
The thickness of the cleaning agent layer must correspond to the thickness of the coating layer.… Therefore, for an approximate calculation of the required amount of remover, you can focus on the amount of paint that was once applied.
The air temperature is of no small importance, since at its high rates, the process of evaporation of the cleaning agent is faster, so it may not have time to completely dissolve the paint, and it will also be necessary to process the metal again.
How to remove?
Before treating a metal surface with a washing solvent, you must first thoroughly clean the dirt and dust from the metal, and then proceed to applying the remover.
The detergent composition is kept on the surface for about 20-30 minutes, the exact time is indicated on the packaging of the product … In order to increase the evaporation time, the applied composition is covered with a dense plastic wrap.
When the paint has softened well, wrinkles and begins to flake off itself, you can start remove it with a spatula or wire brush … Removing the dissolved paint is easy. After the paint is completely removed from the metal, it is necessary to clean the surface from the remnants of the remover. The packaging also indicates the means that are intended for these purposes.
If after the first application of the paint stripper it was not possible to completely clean the surface, it is necessary to repeat this procedure the required number of times.
If it is necessary to wash off powder paint from an aluminum surface, it is worth considering the fact that for aluminum, compositions without alkalis are selected that can destroy it.
Considering that solvents are chemical and toxic substances, it is necessary to take care of the safe handling of these materials in advance - it is recommended to use protective clothing, goggles and respirators.
Do not allow flushing substances to come into contact with the skin or mucous membranes. If, nevertheless, it was not possible to prevent this, then the affected area must be rinsed with plenty of water.
After using the wash, it is advisable to thoroughly ventilate the room..
Based on customer reviews, we can conclude that removing paint from metal is a simple and quick process that anyone can handle on their own. There should be no difficulty in cleaning surfaces, provided that the cleaning agent is correctly selected depending on the type of old coating, and all points in the instructions attached to the package are observed.
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