Blackening of bronze and brass. Coloring brass and bronze Black painting with bismuth sulphide

We offer painting with metallic paints:

  • Brass look;
  • Bronze;
  • Under copper;
  • Under gold;
  • Aged metal;

One of our workshop services is painting. various products with imitation of natural metals with the effect of patina and aging. The technology allows you to apply metallic paint to almost all types of surfaces: metal, plastic, wood, plaster.

brass paint samples

When choosing the required painting option, you can be guided by the samples presented at our production. It is also possible to select paint according to the customer’s sample.

The quality of the finishing coating is ensured by the varnish:

To create an aging effect, we use solvent-based patina. The patina is applied over the base coat of paint and using various abrasive sponges, a sanding effect is created in different directions.

Painting the heated towel rail "brass".

painting chrome surface brass effect heated towel rail brass plating


Painting a heating radiator to look like brass.

bimetallic radiator
painting a radiator to look like brass
finishing layer- glossy varnish


Below is a photo of painting bathroom fittings “bronze” with a patina effect. Gloss varnish finish.

painting products in bronze color finishing layer - acrylic varnish antique bronze finish


The chrome plating is removed before painting.

repainting chrome to bronze applying primer painting bronze fittings


Coating chrome handles in aged bronze.

painting door handles in bronze aged bronze handles finishing coat varnish


Painting of installations, drain buttons.
The photo shows samples of painting with the “Antique Brass” effect under glossy and matte varnish.

brass-look drain buttons painting buttons to look like brass
repainting the button in brass (glossy varnish)



Grohe button painted brass
GEBERIT button before painting
painting the button in brass (matte varnish)


Painting the shower cabin to look like antique brass.
Initially, the cabin parts were chrome-plated, with anodized aluminum profiles.

painting aluminum profiles
details after painting
painting a shower cabin in brass


Coloring commercial equipment in brass color.

work in painting booth
old brass surface
shop equipment after painting


Painting the sink bronze.
An excellent example of the durability and strength of polyurethane clear varnish is the painting of such mechanically loaded products as a kitchen sink. The sink is constantly exposed to mechanical stress. The varnish applied to the surface in three layers and completely polymerized (after painting for up to 10 days) perfectly withstands all loads.

washing before painting applying primer bronze sink painting


Repainting the decorative caps on the lantern to look like aged bronze.
To protect the streets lighting fixtures We made custom decorative caps for our customer. The products were originally white. Futile attempts at spray painting led to damage to the product. We had to sand the product and apply an insulating primer to prevent the first layers from being undermined. Next, the product was painted to resemble old bronze and coated with 2 layers of matte polyurethane varnish.

product before painting painting - antique bronze finishing layer - matte varnish


Copper-like painting
The metal housings of the restaurant lamps were painted.

metal lamp copper painting
copper painted lamp


Painting the rotary stand parts to look like “antique brass”.
By order of the Petersburg Doors company, elements of commercial equipment were painted to resemble antique brass. The parts of the rotary stand were previously cleaned and primed. Painted using decorative sanding technology. Acrylic car varnish has an excellent gloss level and is quite durable.

products in the painting booth painting products to look like brass glossy varnish coating


To change the texture and give interior items a noble look, special paints are increasingly being used to achieve the effect of a “metallic” surface.

Metallized paints are available in a wide range color scheme and can imitate the shade of almost any metal. The finished surface acquires the color of brass, bronze, copper or gold, and additional processing craquelure varnish Gives household items a unique antique look.

Advantages of metallized paints:

  • Large selection of shades. You can get the effect of bronze, brass, copper or other metal.
  • Used for external and interior work, wall decoration. Do not contain harmful substances and toxins.
  • They are durable and do not fade over time.
  • Painting products in damp areas.

Such textured paints are used for interior decoration and decoration. various items household items, including furniture, picture frames, candlesticks, etc. Interesting solutions can be obtained by finishing the plumbing fixtures, mirror frames or other individual interior elements “in bronze” or “copper”.

You can cover a fireplace, stucco molding or part of a wall with metallic paint, while the painted surface will highlight how classic style, and will perfectly complement retro-style design or ultra-modern high-tech.

Application technology

If metallic paint is applied to interior items or furniture, then it is necessary to remove the old coating in advance. Before finishing, the surface should be cleaned of possible contamination and apply primer. The key to the durability of painted products is, first of all, the use of correct, high-quality primers for various surfaces: for plastic Plast Prime and for metal Acid 8.

The selected composition is applied in accordance with the manufacturer's instructions, usually to obtain desired effect One layer is enough. A metal-finished design element can be left shiny or given an antique look with the help of a craquelure composition. The characteristic cracks that appear during the drying process of such varnish will artificially age the treated surface.

The resulting effect can be emphasized with burnt umber, which is carefully applied to a dry cloth. The excess should be removed before the composition dries completely, and if desired, cover the metallic finish with a layer of varnish.

Acrylic Brass Paint - protective, decorative paint with a metallic brass effect. Resistant to ultraviolet radiation and weathering, oils and gasoline. Has good adhesion and increased color stability. Withstands temperatures up to 80°C. Suitable for metal, plastics, wood and glass. Ideal for decorative purposes metal structures, for painting gates, forged products, for protection and renewal appearance steel pipes etc.

METHOD OF APPLICATION. The surface to be prepared for painting must be dry and clean, free of rust and grease. For highly absorbent surfaces, it is recommended to apply a sealing layer (eg dispersion paint). Shake thoroughly for 2 minutes. Spray from a distance of 25-30cm using side-to-side movements. Operating temperature 18-25°C. The coating will be dry from dust in 10 minutes. Complete cure after 4-6 hours. Sufficient to cover approximately 3 m2.

ATTENTION. Pressurized cylinder. Protect from exposure sun rays and do not heat above 50°C. Dispose of empty cans and waste properly. Do not pierce or burn, even after use. Do not spray onto hot objects or flames. Keep away from sources of ignition. No smoking. Work in a well-ventilated area. Do not inhale fumes. In case of contact with eyes, rinse clean water. Do not allow it to enter the sewer or groundwater. Keep away from children.

Manufactured by Eckart GMBH, Germany. Volume 400ml

Additional option

Meaning additional option

IN MOSCOW AND MO:

Pickup:

The order can be picked up at the address: Volokolamskoe highway, 87, b.1 on weekdays from 10:00 to 19:00. Delivery of goods on weekends by prior agreement.

  • From Tushinskaya metro station: any bus to the stop "Academy of Communal Services"
  • From Volokolamskaya metro station: bus No. 2, 904, 266, 614, 741, 248, 210, 930 to the stop "Academy of Communal Services"
  • From Mitino metro station: bus No. 614, 741, 266, 930 to the stop "Academy of Communal Services"
  • from Pyatnitskoye Shosse metro station: bus No. 2, 904, to the stop "Academy of Communal Services"

ATTENTION! Check product availability by phone before your trip!

By courier:

Available in Moscow within the Moscow Ring Road from Monday to Sunday from 10:00 to 21:00.

  • Delivery time is 1-2 days from receipt of order.

Delivery cost in Moscow:

  • 350 rub. when ordering less than RUB 1,000.
  • 290 rub. when ordering more than 1000 rubles.

Delivery cost outside the Moscow Ring Road: 30 rubles/km + 300 rubles. (basic tariff).

To SDEK and Boxberry pick-up points

When ordering, you must select the most suitable item on the SDEK or Boxberry website and indicate it in the comments to the order, or we will clarify it by phone. Delivery time: 2-3 days / Delivery is paid.

Our managers will inform you about the completion of your order by phone or email. You determine your own convenient delivery date and time.

DELIVERY IN RUSSIA:

Cash on delivery (Russian Post):

  • When delivering by cash on delivery, you pay for the goods upon receipt at the Russian Post office.
  • Postal delivery is carried out by the Federal State Unitary Enterprise "Russian Post".
  • Delivery time is approximately 5-15 days on average, depending on the remoteness of the delivery region.
  • According to postal rules, the weight of the parcel should not exceed 10 kg. If exceeded, the order will be divided into several shipments.
  • The cost of the delivery service depends on the weight of the ordered goods, their cost, current postal rates, and is calculated individually when placing each specific order at the stage of selecting delivery and payment methods.
  • In order for your order to be completed quickly and efficiently, please indicate the exact postal address with zip code, full name of the recipient and contact phone number.
  • Our managers will inform you about the completion of your order and the date of dispatch by email. According to postal rules, an item not claimed by the recipient within a month is returned to the sender. Please receive your orders by mail promptly.

ATTENTION! When choosing the "cash on delivery" delivery method, a partial prepayment is charged, which depends on the cost of sending to the destination and the cost of the goods.

SDEK courier service

More information about SDEK company

Courier service Boxberry company

Learn more about Boxberry. Please check with our managers for the cost and delivery time.

Transport company:

  • We ship the order with the transport company you specify. Delivery to transport company within Moscow it is free. The order is paid before shipping, i.e. by prepayment.

PAYMENT

For cash:

  • Payment is made at the delivery address, after inspecting the delivered goods and reading the accompanying documents. Payment of delivery costs is made simultaneously with payment for the goods. Payment for delivered goods is accepted only in rubles.
  • You can refuse to purchase a product after it has been delivered. In this case, payment is taken only for delivery.

By bank card:

  • Payments accepted bank cards VISA and Mastercard. You can pay by card through a terminal at the pick-up point or through the RosEvroBank electronic payment system (in this case, you will receive an email with payment instructions).

By bank transfer:

  • For organizations, payment by bank transfer is possible with the provision of all necessary documents.

Payment by cash on delivery:

  • Cash on delivery involves delivery by mail and payment upon receipt of the order. By choosing this method, you will have to additionally pay a commission from the Federal State Unitary Enterprise "Russian Post" in the amount of 4-7% of the cost of the order with delivery for sending money. When choosing this method, please pay attention to your full name. the client placing the order coincided with the data of the real Recipient.

RETURN OF GOODS

  • Return of goods is made to the address: Moscow, Volokolamskoye Shosse, 97 from 13-00 to 17-00 from Tuesday to Thursday. We kindly ask you to coordinate your arrival time by phone in advance.
  • Returns of goods from other regions are carried out by postal delivery. If the buyer refuses the goods of proper quality, the cost of delivery of the goods from the buyer to the seller is not refunded. Return cash carried out within 10 days from the date of receipt of the return kit at the store.

Metal is widely present in our premises, and is used where its unique physical properties compared to other materials are needed. However, metal often also decorates the living area with its presence. And in order to make its visual characteristics even more interesting, the metal surface can be given a particular color or texture. Metal painting itself is most often done for protective purposes, but the technique decorative painting has a lot of differences.

Coloring with decorative properties most often affected by various metal objects, lamp covers, heating radiators, sinks and similar items. In this case, work can be carried out both on objects used indoors and on external metal elements.

Advice for those who are planning to paint a metal surface at sub-zero temperatures

Although this advice may apply more to ordinary painting than decorative painting, situations are different. For example, you need to immediately paint a part that has just been brought in from the cold. Therefore, we will give some tips:

  • The most the best way painting in the cold is the use of alkyd enamels with a jelly-like consistency, which have high adhesion (the ability to penetrate the surface structure);
  • Painting a surface cooled to temperature values below +5 degrees Celsius, should be carried out exclusively with pre-treatment this very surface with a torch or heat gun. Otherwise, condensation will form on the surface on which the paint simply will not adhere;
  • If the room itself is cold when painting, the drying time of the layer can increase several times, which is especially unpleasant for decorative painting. Therefore, it is recommended to install heat gun, and cover the surface with film.

What are blacksmith paints

IN lately are very popular blacksmith paints, specially optimized for working with forged materials. Such paints are applied to forging for decorative purposes, which makes it possible to imitate the most various surfaces, starting from gold and ending with cast iron.

The cost of such paints is higher than that of ordinary ones. However, this is due to their increased shelf life, which reaches 5 years or more. At the same time, such paints also look really impressive, allowing you to give the required visual effect by the very fact of their presence. No need to apply various ways coloring.

Today there are many types of such coating, but the most popular is the German WS-Plast paint, produced by Weigel & Schmidt GmbH. These paints allow you to give metal surfaces a variety of different colors and textures. Here you go emerald color, and graphite characterized by red tones, and various types antique colors. Moreover, such a coating not only decorates, but also protects the metal surface from corrosion and other troubles caused by the influence of nature.

Also popular is hammer paint (Hammerite), which is currently becoming more and more in demand. The reason is that such paint does not require the application of a primer, and can even be used directly on surfaces damaged by corrosive processes. However, if the rust is loose, it will still have to be removed. The surface treated with this coating becomes monochromatic with the effect of unevenly shaped patterns and aluminum flakes.

The application of this paint is mainly practiced on ferrous metals such as steel and cast iron. However, it can also process some non-ferrous metals.

How to show patina

Patina is a characteristic greenish coating that appears on the surface of copper and bronze products after oxidation. On at the moment The best way to show this effect is WS-Patina paint. In this way, it is possible to age the metal and give it a characteristic respectable shine.

Antique painting

One of the most popular ways to paint black metal is the antique effect. In this case, several coating options are applied to the metal surface in a certain order. But first, the metal itself must be properly prepared. Him in mandatory cleaned from corrosion, sanded, remove dirt and grease. Only when you are confident that the surface is clean can you begin the process, which is divided into several stages:

  • Using a brush, apply metallic paint to the surface. Don't be afraid to do it casually, as this will only help with the effect we are creating;
  • Once the first layer has completely dried, it is necessary to apply a craquelure primer. The latter allows you to obtain a layer of transparent film created from polymers;
  • The craquelure coating is applied after the primer layer has dried, which allows you to get characteristic cracks, similar to those that appear on things that have been used for decades and even centuries.

Important! Instead of a craquelure composition, the effect of antiquity can be achieved by applying burnt umber to the paint. In this case, it is best to work with a dry cloth, and remove the residue after the paint layer has dried.

Bronze metal painting

Bronze coating is one of the most visually impressive. Therefore, people often strive to recreate it. And there are several ways to do this, and they all involve the use of bronze paint.

First of all, the surface is prepared. Dirt, grease and rust are removed. After this, a layer of metal primer is applied to it, which will increase the adhesion of the layers applied above. At the third stage, bronze metallized paint is applied in 2-3 layers.

If you want to give this bronze layer the effect of antiquity, then the recesses must be treated with patina, which allows you to get the effect of darkening over time. After this, glazing is carried out, during which we go over the protruding elements and those places that are characterized by abrasions with white paint. After the latter has dried, a transparent varnish is applied to seal the effect.

Conclusion

Painting for all other types of metals occurs in a similar manner. Modern metallic paints allow you to create the effect of brass, copper, silver, gold and other metals.

Don’t be afraid that you won’t succeed. Practice shows that such methods of metal processing are feasible without any serious knowledge. The video tutorial below will give you comprehensive information on this matter.

Metal products are susceptible to the influence of the external environment and especially humidity. Metal can be protected using special anti-corrosion coatings (for example, covering the surface with zinc), as well as painting. Paint not only acts as a protector against corrosion, but also gives the surface a more aesthetic appearance.

Decorative painting of metal allows you to imitate a wide variety of effects. For example, you can decorate the surface with bronze, silver, or give the metal an aged, noble look. How to choose a paint material, prepare the base and apply paint to it will be discussed below.

Surface preparation

First of all, you need to evaluate the strength of the old coating. Painting tape will help with this: we make cuts in the old paint and glue the tape to these places. Then, with a sharp movement, we tear off the tape. If a significant amount of paint comes off after the tape, the surface is not strong enough. If the layer is durable, then it is not necessary to remove it; you just need to clean the metal from dirt, traces of rust and dust.

Pay attention! When it comes to heating batteries, old paint must be removed, because V in this case Each additional layer reduces thermal output.

Surface cleaning (metal, walls, etc.) can be carried out in one of three ways:

  • mechanical (using abrasives or tools);
  • chemical (using alkaline compounds or active solvents);
  • thermal (using a hot air gun or an oxy-acetylene torch).

Padding

Surface treatment with a primer is necessary to create reliable adhesion between the metal and the paint. Primers are made on the basis of synthetic or natural film-forming substances (organic resins, drying oils, etc.).

An important property of primers is to reduce the likelihood of corrosion. Depending on the type of primer composition, the mechanisms for providing anti-corrosion protection differ.

There are several types of primers based on the nature of their anti-corrosion properties:

  1. Insulating. Such primers do not allow moisture to reach the metal being protected.
  2. Passivating. The effect of passivating compounds is based on reducing the electrochemical activity of the material.
  3. Protective. Such primers contain highly dispersed metal powders, which electrode potential lower than that of the protected metal. This provides protection against corrosion.
  4. Phosphating. A coating containing phosphates protects the metal from corrosion.
  5. Inhibitory. An inhibitor is a substance that reduces the rate of development of chemical reactions. Because rust formation is a result chemical reaction, inhibitory primers reduce the rate of development of corrosion processes.
  6. Rust converters. Rust converters transform iron oxide into an insoluble compound.

The primer composition is applied using a brush, roller, swab or spray. The primer layer should not be too thick - thinner than subsequent layers of paint. Optimal thickness primer layer - up to 0.1 millimeter.

If the primed surface is matte, it must be carefully sanded with fine-grained sandpaper. This will improve the quality of adhesion with paint and varnish material.

Puttying is necessary to eliminate defects such as cracks, as well as to level the surface. The putty composition is a mixture that includes filler (chalk), plasticizer, binder, special additives.


Application of various putties

Putty mixtures are sold in one of two states - dry (diluted in water) and ready-to-use (diluted in solvent). The putty is applied and spread over the surface using a spatula.

Choosing paint for metal

For coloring metal surfaces Organosoluble paints and varnishes are most often used. Such solutions are a mixture of synthetic resins of alkyd origin and organic solvents. White spirit or styrene are most often used as the latter.

After drying alkyd compositions thick, durable, transparent, almost colorless films appear. Such films are resistant to all kinds of chemicals, as well as moisture. Thanks to this latter quality, alkyds are found wide application not only indoors, but also outside buildings.

However, when choosing a composition, you should pay attention to the recommended purpose of the paint. For example, for coloring batteries there are special compounds, which are characterized by high thermal conductivity and do not reduce the heat transfer of equipment.

For a long time, painting was not used on forged metal. There was a generally accepted opinion that paint eliminated the advantage self made, hides the natural texture of the material.

However, not so long ago, paint and varnish materials for forged products appeared that make it possible to artificially age the material, create the appearance of patina, or achieve other visual effects. Forge paints also protect metal from corrosive processes.

The main disadvantage is their cost. Like the creation of forged products, specialized paints cannot be called cheap.

Metal painting

You can apply paint using a brush, roller or spray. The number of required layers when painting is set by the manufacturer and depends on the hiding power of the paint. Hiding ability is the ability of a paint and varnish material to hide the color of the surface being treated. The hiding power is inversely proportional to the transparency of the paint and varnish material, that is, the more transparent the paint, the more of it will be needed.

Pay attention! The hiding power is indicated on the paint packaging and is determined by the material consumption per square meter.

Difficulties may arise when calculating the required amount of paint and varnish material. Manufacturing companies provide information on consumption per square meter. When it comes to painting flat surfaces, it is not difficult to calculate the consumption. However, we often have to deal with uneven surfaces- gratings, fences, figured parts, etc. In such cases, the calculations will have to be based on your own experience or the advice of the seller.

Bronze surface decoration has been used for a long time. However, until recently, such paints were made on an organic basis. Thus, the scope of use of such paints and varnishes was significantly narrowed due to the characteristic properties of organic solvents. unpleasant odor. In addition, such surfaces are not resistant to temperature changes.

Today, the most popular paints are water- and acrylic-based. Such compositions are characterized by safety, ease of use, resistance to high and low temperatures, as well as anti-corrosion resistance.

There are two ways to decorate a bronze surface. Below are two step-by-step instructions.

The first option is plain coloring:

  1. We remove dirt and traces of rust from the surface. We carry out degreasing.
  2. We prime the surface. This will improve the adhesive properties of the materials and, in addition, create a layer of polymer that will protect the surface from corrosion.
  3. When the primer dries, apply 2-3 layers. Moreover, each layer can be applied only after the previous one has dried.

The second option is aged bronze:

  1. We carry out preparatory activities the same as described in the first case. Then we prime the metal and paint it bronze.
  2. We treat the grooves on the surface with patina. It can be translucent - this will allow you to control the level of darkness.
  3. When the paint has dried, take a dry brush and glaze. To do this, apply light paint to the corners and protrusions in such a way as to create a scuffed effect.
  4. After the layer has dried, apply a clear varnish to the metal.

You can give the metal an aged look in another way, using a craquelure primer and paint.

Instructions:

  1. We clean the metal from dirt, traces of rust and grease.
  2. Cover the cleaned and dry surface with paint and varnish material. For coloring we use a brush, since uneven coverage in this case is only beneficial.
  3. When the paint is completely dry, apply a craquelure primer. This composition can be purchased at hardware store. After drying, a transparent polymer film will appear on the surface.
  4. We create the main craquelure coating. The result of the work is aged metal with traces of rust. Moreover, small cracks - craquelures - will appear on the surface.

Coloring and low temperatures

Recommends painting surfaces at positive temperatures. It is believed that the minimum permissible temperature is 5 degrees above zero. However, there are situations when you need to paint a surface urgently, despite the thermometer readings. And in this case, high-quality coloring is possible if you adhere to a number of recommendations, which will be discussed below:

  1. We clean the surface from ice, dust, dirt, rust and condensation. Moreover, standard cleaning procedures - mechanically- in this case it will not be enough. Even if very little condensation remains, all further efforts will not create high-quality coating. To dry the surface thoroughly, use a burner (gas or gasoline) or a heat gun.
  2. At low temperatures the paint will dry 2-3 times longer. Based on this, it is necessary to protect the painted surface from environmental influences. Suitable for this polyethylene film and a heat gun.

Equally important for painting at low temperatures is choosing the right paint. The best option considered jelly-like alkyd enamels. Such compositions are distinguished by high adhesive qualities.

» Chemical staining of brass

Chemical dyeing brass

Having purchased, at one time, photo-etching from a Czech company Extratech for Tu-154M (on a scale of 1:144), I was amazed at the subtlety and delicacy individual elements. I was especially pleased with the filigree imitation of riveting on the reverse buckets. The engine nozzles are of large scale thickness. The rims on the chassis disks also look realistic.

The impression was intensified by the new release for Il-62M , having the same D-30KU engines.

At the same time, it became clear that trying to prime and paint small parts now means ruining everything! Moreover, there are many methods of chemical processing of brass that allow you to give it any color.

Majority chemical reagents always at hand - salt, soda, water. But it is still better to conduct experiments outdoors or in a well-ventilated area, since toxic fumes and gases may be released. And no one canceled glasses and rubber gloves.

So, armed with long-forgotten chemistry textbooks and the Internet, let's begin!

P pre-bleaching of brass

Brass is an alloy of copper and zinc, sometimes with the addition of tin, nickel, lead, manganese, iron and other elements. And if copper has a pinkish tint, then brass is golden yellow.

Both brass and copper oxidize and darken in air. Therefore, before chemical treatment It is imperative to remove oxides from the photo-etched surface.

RECIPE:

Alcohol or acetone
Citric acid (available in grocery stores)
Table salt

Into a glass hot water add a teaspoon citric acid and a teaspoon of table salt.

Photo-etching is degreased with alcohol or acetone and placed in the solution for 5-10 minutes. When finished, wash with water and detergent.

You cannot use metal utensils as a container, and removing the product with steel tweezers may leave a copper coating.

Bleaching accelerates with increasing solution temperature or citric acid concentration.

Important! Do not overexpose the product in acid - the so-called “dezincification” of brass may begin - it becomes unnaturally pink-red.

The bleach solution is corrosive, so you should avoid getting it on your hands and clothing.

Brass bluing

So, let's try to imitate the color of the low-pressure blades of the Tu-154M engine.

For work we will need:

1. 10% ammonia solution (sold at any pharmacy);

2. HOM - copper oxychloride (sold in gardening stalls);

3. Glass jar.

Pour a little ammonia into a jar and add half a teaspoon of HOM. Stir. Add some water.

At first the solution has a cloudy turquoise color, then becomes inky blue.

After degreasing with medical alcohol, we hang the brass part on a thread and dangle it in the solution for about half a minute. Then rinse with clean water and dry.

The part takes on a beautiful olive-brown color, very similar to tape. The surface is perfectly flat.

It is important not to overexpose the part in the solution. It may become brittle and crumble.

Having created a dark base, we can now apply thin layer liquid-diluted metallic enamel paint of any color.

The entire operation from start to finish took no more than ten minutes.

Attention! Ammonia vapors are very harsh and poisonous. It is better to carry out the process outside, wearing a respirator.

In conclusion, I want to answer the skeptics who they will say that working with photo-etching is long and difficult:

Nothing imitates metal more than... metal itself.

I express special gratitude to my colleague Sergei Utenko from Novosibirsk for valuable advice and comments