How can you treat the inside of a hot water tank?

The problem of rusty water in the tank of a sauna stove can not only ruin a real holiday, but also lead to a lot of other problems, for example, clogging the hot water supply tap or damaging the shower column. These and other problems become a real headache for bathhouse owners who have installed a metal water tank that corrodes when in contact with water. But this problem can be solved using time-tested methods of protecting metal from corrosion and new technologies to combat it.

How to flush a motorcycle fuel tank?

Where does rust come from in a water tank?

The appearance of rust in the tank of a sauna stove is common for containers with an open volume. This is especially true for homemade containers, which are created using steel or metal sheets or large diameter pipe sections.

Upon contact with water, and even more so when the temperature rises due to a chemical reaction, the walls are first covered with a small layer of oxide, and over time the corrosion process becomes widespread. The containers most susceptible to these processes are in bathhouses, which are used occasionally, and especially in cold times, when the room remains unheated and after the procedure is completed, the water is drained from the tank.

Corrosion does not bypass tanks in heated rooms; this process takes a little more slowly, but there is no escape from it. The process lasts slowest in tanks that are constantly filled with water, but here, too, over time, rust is deposited on the walls.

There are several reasons for the occurrence of rust - contact of water with unprotected metal, the presence of iron oxide in the water itself, saturation with chemically active substances that promote corrosion.

FAQ.

Production experience since 2010!

Frequently asked questions in Ural-sad.RF [td]

Question:

Why don't you paint sauna stoves with heat-resistant paint?
Answer:
Sauna stoves become very hot during operation, so part of the coating, especially at the bottom of the stove, will burn and therefore turn black. Another disadvantage of painting is the long and strong smell of burnt paint (lasts about a month while the paint burns out), so washing in a bathhouse turns from a pleasure into an ordeal. Therefore, instead of paint, I recommend using a safe solution - whitewashing the stove in a bathhouse with ordinary lime - it is not dangerous to health, the stove is white and light!

Question:

But now you have started painting stoves with heat-resistant paint.
How do you explain this? Answer:
Yes, we have found the optimal Russian paint for painting our stoves. Feedback from our customers has shown that once or twice you heat a stove painted with this heat-resistant paint and the smell disappears. Since customers claim that this is so, we will paint some of our products with this paint. Well, the look and feel of the product is different.

Question:

But some paint manufacturers claim that their paint can withstand temperatures up to 800 degrees Celsius and higher.
This paint should not burn on stoves. Answer:
The bottom of the stove gets very hot, until the metal turns red (if you heat it for a long time), so no paint will withstand it, well, at least I haven’t seen one. Yes, and as I wrote above, the smell of scorched paint will discourage all desire to steam in such a bathhouse.

Question:

Is it possible to make brickwork on the chimney from your sauna stove?
Answer:
It’s not possible, but it’s necessary! By the way, the safest installation of a chimney for a sauna stove consists of brickwork, from the stove and just above the ceiling of the sauna. This is the most reliable fireproof method! You can also insert a cast iron view into the brickwork.

Question:

Does the water in the tanks rust?
Are the tanks being processed? Answer:
Yes, the water in the tanks rusts over time, which causes corresponding inconvenience when visiting the bathhouse, but from the beginning of 2016, we began treating the tanks with a special compound that prevents metal corrosion. It lasts for 1-2 years, after which the procedure is repeated. The components for processing the tank are publicly available. The water in the tank remains clean.

Question:

How to take water from the tank?
Scoop with a ladle? Answer:
No, an outlet with a tap thread is welded into the side of the tank (standard Ф=20). Therefore, it is very convenient, without getting burned, you can draw water in the bathhouse.

Question:

How quickly does the stove and heater heat up?
Answer:
The stove and heater heat up quite quickly! 40 minutes and the sauna is ready! (for a standard 3*3 bath) Attention! It is recommended to splash a little water into the heater and stand next to it on the side, because The water quickly turns into steam and flies out of the heater with a whistle!

Question:

I read on other sites about sauna stoves made of boiler steel (it is of higher quality, as stated) - do you have the same steel?
Answer:
There is no official concept of “boiler steel”. This is more of a marketing ploy. Depending on the operating conditions, carbon steel and low-alloy steel are used as boiler steel. steel, alloy steel of pearlitic and austenitic classes (i.e. it turns out that all other classes of steel, except art. 3, can be classified as “boiler steel”). Let the suppliers provide you with documents (certificates) on the metal from which this steel is made. They can use 09G2S or the same steel 3 as “boiler steel”. It would be better if these manufacturers (suppliers) give a guarantee for their furnaces for at least 5 years. We make stoves from pipes, there is also special steel + the fact that the pipe has a concave shape, so it does not deform during the production process.

Question:

I read on other sites about sauna stoves made of 4 mm thick structural heat-resistant steel - do you have steel of the same quality?
Answer:
We make furnaces from pipes, there is also special steel + the fact that the pipe has a concave shape, so it does not deform during the production process. All sauna stoves made of sheet steel (rectangular or square), no matter what manufacturers (suppliers) say, over time “take away” the abnormal heat in the firebox. This is not a gas stove, where the temperature is constant, in the oven the temperature is variable: sometimes more, sometimes less, metal at variable temperatures sometimes expands, then contracts again, because of this it gradually bends in different directions (within 1-2 years) , welding seams crack and the oven breaks down and becomes a fire hazard! Just physics. Removes the temperature of the walls of a rectangular oven even from 6 mm stainless steel! Does not remove the furnace walls only from the pipe!

Question:

How long will your sauna stove last?
Answer:
A sauna stove from Ural-Sad.RF will last at least 12 years! The oven comes with a 5-year warranty!

Question:

Which oven would you recommend, 2 or 3 sections?
Answer:
The choice is up to you to decide for yourself. The main difference is the price - 2-section ovens are slightly cheaper than 3-section ovens. But 3-section sauna stoves can be rotated in any direction 360 degrees, and if someday something in a 3-section sauna stove burns out, repairing it or buying a burnt-out section will cost less than in a 2-section sauna stove .

Question:

Why do you give a 5-year warranty on greenhouses only for your installation?
Answer:
You yourself must understand that installing a greenhouse is not done in a clumsy manner; considerable efforts, knowledge and skills are put into it. In the process of manufacturing greenhouses, we developed our own installation technology without a foundation or timber. Our greenhouses will not bend under the weight of snow and they will not be carried away by a strong gust of wind! (With proper care).

Question:

What do you mean “with appropriate care”?
Answer:
Having installed a greenhouse, you should not expect that it will not require maintenance, especially in winter. All rules for caring for a greenhouse are described on the website: Superteplitsy.rf. Please read them carefully to prevent premature damage to the greenhouse.

Question:

Why do some greenhouse manufacturers have cheaper greenhouses than yours?
Can you lower the price like others? Answer:
Discounts are always provided if the greenhouse is made of the same thickness of metal, as well as the thickness and density of polycarbonate. When we started making greenhouses, we noticed how cheap the greenhouses offered in the city were; at first we couldn’t understand why it was more expensive for us, the manufacturers. Then we took a caliper and went to the points of sale. Basically, they overestimated the thickness of the profile pipe: instead of 1.5 mm, people are offered 1.2 mm - 1 mm or less (when advertising 1.5 mm), and the thickness of the polycarbonate was also overestimated: instead of 4 mm (which was stated in the advertising) , people were offered 3.8mm or 3.5mm. This difference may not be noticeable by eye, but it can be lost in quality, and, accordingly, in the service life of the greenhouse. Miser pays twice!

Question:

Why are other manufacturers and suppliers of greenhouses, such as a bread box, cheaper than yours?
Can you lower the price like others? Answer:
Discounts are always provided if the greenhouse has the same technical characteristics as ours. In addition to the above-mentioned inconsistencies in the thickness of the corrugated pipe and polycarbonate, there is one very important difference between the “breadbox” type greenhouse and our “sun” type greenhouse. All holes and gaps in our greenhouse are tightly fitted. Having looked at a “breadbox” type greenhouse at our neighbor’s dacha, we were stunned - the gaps at the top and sides when the doors are closed are about 2 cm! This means that when it gets cold, especially at night, the entire crop of tomatoes, peppers or cucumbers will freeze completely, reducing daily care to zero. Another big plus: our greenhouse has two side windows for ventilation, which won’t break the doors in strong winds. You have to pay for quality.

Question:

What guarantee do you provide for the paint and varnish coating of greenhouses and hotbeds?
Answer:
Basically, manufacturers of paint and varnish products provide a 1-year warranty on paint. We cannot provide a warranty on paintwork longer than the manufacturer's warranty - 1 year. By the way, unpainted greenhouses cost no less than painted ones.

Question:

Why does the polycarbonate in some greenhouses and greenhouses turn yellow and crack after 1-2 years?
Answer:
The first reason is low-quality cheap polycarbonate. The second is improper installation of the greenhouse and stretching of the polycarbonate. Here, more than ever, the Russian proverb - The miser pays twice is appropriate.

Painting process

To paint the inner walls of a vessel, it is impossible to use the so commonly used and economical roller or spray gun; only a brush can be used. For work it is recommended to purchase:

wide paint brush for painting walls;
a small brush to paint seams and joints.

You can paint the inside of the tank in the same way as other metal surfaces:

Using a wide paint brush, apply a layer of paint onto large substrates without drips or streaks.
Weld seams and corners are carefully painted with a small brush.
The product is left to dry completely for several hours (drying time is indicated on the packaging of the product used).
After the first layer has dried, re-painting is carried out following the same steps.

The instructions for most coloring compositions state that one coat of paint is enough to provide reliable protection, but experienced craftsmen recommend applying another one. This is based on the fact that beginners can make mistakes in their work, for example, unevenly distributing the composition over the surface, poorly painting individual areas. In any case, applying an additional layer will take a little time and money, but the quality of the work will significantly increase.

After painting with paints and varnishes that prevent the development of corrosion, a sauna heating tank will last much longer. The main thing is to use the selected product in accordance with the attached instructions and carefully follow all stages of preliminary preparation of the product for painting.

Other. Industry sections

Good day to all! This is the problem. I am making a metal stove for a bathhouse; the tank will also be made of steel. How to protect it from corrosion? The tank is not welded yet. Attached is a rough sketch of what I want to do.

PS do not write “make a stainless steel tank”, since I don’t have one.

Message from Shishkov V.S. : In villages, such tanks do not provide any protection at all. After some time, a thick layer of scale appears inside the tank, and this serves as protection against corrosion.

Somehow, scale forms for me more slowly than common rust.

and in villages brass soldered tanks are common. they do not rust, and there is no need to protect them.

Shishkov V.S.

right There is no need to paint anything - it’s useless. To avoid “rusty boiling water”, you don’t need to boil it, just heat it up. And take hot water from a clean place.

Much depends on the design of the stove - the tank for heating water does not have to be welded and huge. For hot water, there can generally be a remote tank of any design - even from a stainless steel washing machine, or from galvanized steel. Water should be heated not with fire through the wall, but in a coil (register) built into the stove.

Here is my stove Model

- very unfortunate, a lot of space, a lot of metal, a lot of fuel and “rusty boiling water”.

Message from mak# : Simply place a cast-iron enameled boiler in the oven as a tank. They sold these before, but I don’t know now.

The simplest solution. In many villages, such a cauldron is simply smeared into a brick oven. Enough for the whole family. It is quite possible in a compact steel firebox. Only now it is almost impossible to find an enameled cast iron “cast iron”.

As an educational program for those proposing to paint. I once went through such an educational program myself - we had a special coatings department, where very good specialists dealt with painting and galvanizing technology. They knew everything about any paints.

1. Any paint coating, if you look under a microscope (they showed it to me), looks like a mesh with holes. The size of the holes depends on the material, but they are always there. The medium penetrates through the holes - be it water or acid.

2. To get rid of holes, apply several layers of paint - up to 7 layers, depending on the aggressiveness of the environment. Water is actually a universal aggressive solvent, although we don’t think about it.

3. Paint must be applied over the primer. Paint has poor adhesion to metal, but primer has good adhesion. But for priming it must be cleaned and degreased. All kinds of “rust-based” paints do not provide a reliable coating.

You can't make a good coating at home. Anyone can be convinced - just try painting a tin can and heating water in it several times.

And even in industrial conditions, painted water containers are unreliable. They still need to be repainted periodically. And in everyday life, a tank in which the paint peels off in water is much worse than one that has not been painted.

But stainless steel, or just galvanizing (any tinsmith can do it) is much better. Titanium is even better - but it's exotic. When we did electroplating with titanium air ducts, on the quiet, of course, we made ourselves some tanks. From whom it was not stolen, nothing has happened in 35 years.

Preliminary processing

Just painting the tank is not enough. If you do not prepare it first, then all the work will be useless: when the water inside the container is heated, the dye will peel off in pieces, contaminating the water masses. To prevent this from happening, before painting the surface from the inside it is recommended:

clean from rust, dirt and scale;
degrease;
treat with anti-corrosion agents (if there are traces of rust);
prime if necessary (most anti-corrosion paints are primer-enamels that combine the qualities of these two products).

Cleaning

It is recommended to clean the inner surface of the water tank in the bathhouse mechanically. For this you can use:

hard metal brush;
a grinding machine with an attachment for cleaning metal.

Traces of scale and water deposits are carefully removed from the metal base, and traces of rust are cleaned. After complete cleaning, the vessel is first washed with detergent and then rinsed.

If you plan to paint the new tank to prevent corrosion damage, you can simply wash and rinse it. After rinsing, wipe the inner walls dry with a rag and let them dry a little.

Degreasing

No matter how high-quality the washing is, there is always a risk that grease stains will remain on the metal base, which will impair the adhesion of anti-rust preparations, and therefore the protection of the metal will be incomplete. For degreasing use:

White spirit and other alcohol-containing solutions. They are convenient because they leave no odor after drying.
Gasoline and solvents. All traces of grease are removed efficiently, but in the first time after painting, the water in the tank may have a specific odor.

The degreaser is applied to the metal base and left until completely dry.

Anti-corrosion treatment

If rust has already appeared, its further development can be stopped using anti-corrosion agents. When choosing a drug, it is important to consider not only the method of influencing corrosion, but also its compatibility with the finishing dye. For processing it is customary to use:

Insulating agents that cover the surface with a durable film, preventing the access of liquids to it. Most often, insulators are made on the basis of lead white and are an ideal substrate for lead paint.
Passivating, slowing down rusting. Excellent combination with epoxy enamels and paints. Often epoxy paints combine the qualities of a protective solution, primer and paint, and the finishing with such products is applied immediately after degreasing.
Protectors that contain tiny metal particles and, when dry, create a metallized film. Treatment with this product is well suited if you plan to cover the inner walls with a mixture of glass and aluminum powder.
Compositions with orthophosphoric acid. The content of orthophosphoric acid in the preparation allows the composition not only to prevent the appearance of rust, but also to “treat” existing damage, converting iron oxide (rusting product) into durable and inert to chemical compounds iron phosphate. Orthophosphorus compounds are recommended for use in cases of deep corrosion that has thinned the tank wall.
If you plan to paint the inner walls of the tank, it is recommended to purchase a rust converter based on silicic acid at a car dealership, dilute it with water in a ratio of 1:3 and leave it in the tank overnight, and then thoroughly rinse the vessel and dry it. This method will almost 100% avoid “chemical conflict” after applying the finishing finish.

What can you paint with?

There are many heat- and moisture-resistant paints that can be used to protect the hot water tank in a bathhouse for a long time by painting it inside. These dyes include the following types.

Ethyl silicate with the addition of zinc powder

Available in the form of two components: ethyl silicate base and zinc powder, which must be mixed before painting the surface. After a day of drying, you can heat the water in the tank without fear of damaging the paintwork material.

Important! All preparatory work before painting with ethyl silicate composition must be completed at least 6 hours before painting begins. For complete polymerization of the dye, temperatures from minus 15 to plus 40°C are suitable.

Cetra

Unpretentious heat- and moisture-resistant paint that can withstand exposure to hot water for 7 years. This dye is used to paint the inside of tanks in gas and oil refineries. It not only withstands high temperatures and humidity, but is also resistant to most chemical elements. The decision to paint the tank in the bathhouse with this enamel will be the optimal solution to prevent corrosive destruction.

Anti-corrosion zinc-filled enamel

When applied, a durable steel-gray film is formed that can withstand high mechanical stress. The best option for painting the inside of a water-containing container is if the tank is open and hot water is scooped from there with a ladle. Impacts of the ladle against the walls of the vessel will not harm the painted surface.

Lead iron dyes

On store shelves you can find many different versions of this paint, which have high moisture resistance and anti-corrosion protection. Most of these coloring preparations are heat-resistant and can withstand temperatures up to 300°C. When purchasing red lead drugs, you should carefully study the instructions on the package. Any of the heat-resistant dyes will be a suitable solution for painting the inside of a hot water container.

Epoxy enamels

Able to withstand temperature changes from -50 to +120°C and exposure to most chemical compounds. Contains passivating (rust-inhibiting) elements.

Heat-resistant water-dispersion heat-resistant materials

Able to withstand heating up to 120°C. No chemical reactions occur inside a container painted with this composition, and the liquid, after heating, can be used not only for hygienic needs, but also for drinking.

A mixture of liquid glass and aluminum powder

Previously, before the advent of heat- and moisture-resistant paints and varnishes, it was considered the optimal means for protecting the tank, but even now this method is used only for treating the internal surfaces of water-containing containers. The mixture of glass and aluminum can withstand heating up to 700°C, does not affect the composition of water and is environmentally friendly. It is believed that the liquid from a tank painted with this composition can be used for drinking even after heating.

Mixture of lime and cement

It is done in a 1:1 ratio. You can paint a container for heating water in a bath using this method. The mixture, diluted with water to the consistency of porridge, is applied to the inside of the walls, dried, and this stage is repeated 5-7 times. The protective properties of this composition are low, so now it is used extremely rarely.

Use of improvised means

Folk remedies can partly help temporarily solve the problem. The set of measures includes all stages of metal processing - cleaning, installation of a protective layer and its fixation on the inner surface.

To combat rust, acid-containing substances are most often used. Upon contact with metal, the acid reacts and forms a stable oxide layer on the surface. Experienced bathhouse attendants recommend pouring 50-100 grams of citric acid into 20 liters of water and boiling the tank. The oxide film will protect the surface for one to one and a half years.

A more modern option suggests treating the walls with a special anti-rust agent. This is a more effective method, but after it it is necessary not only to rinse the container, but also to apply a protective coating.

The following can be used as a coating using available materials:

Aluminum powder mixed with liquid glass (silicate office glue) - the composition forms a heat-resistant coating that can withstand 2-3 years of active use;
Red lead is a filler or the main primer for compositions used to paint metal surfaces (the bottom of sea vessels is painted with red lead);
The lime-cement coating is prepared in a 1:1 ratio. Apply to a dried surface. For best results, it is recommended to apply 3-4 layers of treatment.

From the video you can learn how to paint a container with red lead.

The disadvantage of these methods is the complexity of the coating application and the relatively short duration of the protection. On the other hand, these methods allow you to quickly and effectively provide rust protection with truly affordable means.

conclusions

We have analyzed the main risk factors and mistakes of bathhouse owners. Provided that the tanks, heat exchanger and other equipment are connected correctly, the equipment will work for many years without the need for repairs. Also, do not rely on chance and neglect the water filter.

Important! Remember that the hardest water is well water, as well as river and tap water. Therefore, creating high-quality water filtration will help keep tanks and other equipment from developing plaque.

In general, using tanks and barrels in a bathhouse is not accompanied by great difficulties. The main condition for good operation is compliance with the rules of connection and operation.

Modern methods of protecting tank coatings from rust

More advanced and reliable methods of protecting the internal surface from rust formation are technologies for applying a protective coating using multi-component paints and coatings.

Ethyl silicate coatings with the addition of zinc powder

One of the most effective means is coating the inner surface of ethyl silicate coatings with the addition of zinc powder. The technology is based on the polymerization process of ethyl silicate compounds. The zinc powder contained in these compounds forms a coating that does not react with iron and water. In addition, this coating can withstand heating up to a temperature of 200 degrees, which fully corresponds to the heating mode of the tank in the bathhouse.

Painting with heat-resistant paints that provide protection from moisture allows you to protect the tank from corrosion for up to 7 years. One of the products is Cetra, a heat-resistant paint that can withstand heat up to 350 degrees. After hardening, it withstands contact with most aggressive substances, so there will be no problems with heated water when covering the surface of the tank.

Epoxy enamels

Epoxy enamels, when applied to a surface, form a uniform coating that can withstand metal heating up to 120 degrees. This is one of the most affordable means for processing a metal tank. The product has high adhesion and at the same time an expansion coefficient close to that of metal. The plasticity of epoxy compounds allows for reliable surface coating regardless of temperature changes. In addition to recipes that you can prepare yourself based on liquid glass and aluminum powder, the market offers compositions for treating heating devices and sealing seams of high-temperature equipment.

Polymer compounds saturated with metal powder

In addition to the above means, a good effect is obtained by using anti-corrosion metal-filled compounds. These polymer compounds, saturated with metal powder, form a stable surface coating, which over time, through the process of diffusion, forms a reliable protection for the metal. The positive side of this product is its reliability and resistance to mechanical stress. Enamel is not afraid of not only temperature changes, but also mechanical damage, it is not afraid of impacts, which is important for a water tank in a bathhouse.

As for heat resistance, the enamel can easily withstand temperatures up to 300 degrees. An example of the use of such products is enamels for the restoration and repair of bathtub coatings.

Now that almost the entire arsenal of means for installing a protective coating has been revealed, all that remains is to choose a product, prepare the tank and apply the protective layer. Moreover, all methods and means do not require the use of special equipment and special skills to successfully complete the work.

How to choose for cold and hot water

As a rule, two tanks are used in any bathhouse.

One barrel in the bathhouse is needed for cold water.

Another tank is for hot water. The container where the hot water will be located requires careful selection. It is much easier to deal with the purchase and installation of a cold water tank. You don't have to wait for the water in this container to heat up.

Accordingly, the material from which the barrel will be made for ordinary water, which you will not heat, does not matter much.

Stainless steel water tanks for baths are especially popular.

Pay attention to these models to effectively use your bathhouse for many years and not waste time on equipment repairs.