Imitation (painting with transparent paints) of wood of simple species for more valuable ones plays an important role in the color design of furniture. The color and texture of wood depends primarily on its species, but the color of the wood can be changed, if necessary, with special dyes. The quality of the imitation depends not only on the dyes, but also on the wood being processed.
For walnut, birch, linden, beech, alder, satisfactory spruce are well imitated; under mahogany good - pear, alder, cherry, ash, elm, beech, satisfactory - spruce, birch, cedar; under the rosewood - good maple, satisfactory - alder, pear; under ebony - well birch, oak, maple, pear, apple, plum, hornbeam, satisfactory - aspen, poplar, beech To imitate wood, various dyes are used (preparing solutions from them), which easily penetrate the wood.
For dyeing wood, walnut stains (humic dyes) are widely used, as well as all kinds of mordants (copper or iron vitriol), chromate or dichromate potassium, potassium permanganate, ferric chloride (copper chloride), with which the wood is preliminarily etched, and then painted with non-etch dyes.
Wood species containing tannins (oak, chestnut, walnut, etc.) can be painted without pretreatment.
To prepare coloring solutions, use water softened with soda ash (about 0.1%) or ammonia (5%).
The water is heated to 60-80 ° C, the required (according to the recipe) amount of dye is poured into it, stirred until completely dissolved and allowed to stand for 48 hours. The settled solution is poured into another dish. If a part of the precipitate falls, the solution is defended a second time and filtered. Undissolved residue leaves stains and streaks on the surface of the wood.
For a more uniform staining, the wood surface must first be moistened with water using a tampon or cloth.
The prepared coloring solution is applied to the surface of the wood only along the grain with a brush, a spray bottle, a greasy sponge, and a clean cotton rag. After dyeing, wipe the surface of the wood with a clean cloth, removing greasy smudges that leave stains and streaks.
In order for the coloring solution to penetrate deeper into the pores of the wood, it is heated to 50-60 ° C. Painted products must be dried for at least 1.5-3 hours at a temperature not lower than + 18 ° C, but it is possible for a longer time until the paint is completely dry.
Various dyes are used for direct dyeing of wood. For example, for dyeing birch, beech, oak in reddish-brown color, 10 g of walnut stain is taken per 1 liter of water. For dyeing in the reddish-brown color of birch, take 20 tons of nut stain or 2 g of "Ruby" dye per 1 liter of water.
In addition to direct dyeing, a mordant is used, in which the surface is first treated with a solution of salts of some metals, and then, after 10-15 minutes, painted with a solution that reacts with the mordant, forming a water-insoluble compound. Depending on the used stain and its concentration, the color of the wood color can be different.
The holding time between the application of the etching solution and the dyeing solution is 10 min.
For example, pine and larch wood is painted brown in the following way: first, it is etched with a solution of resorcinol (20 g per 1 liter of water), then covered with a solution of chromopic (10-30 g per 1 liter of water). Exposure between pickling and dyeing - 1 - 2 hours. Birch under the walnut is painted as follows: pickled with brown dye for fur (2-5 g per 1 water), painted with acid orange and potassium chromate (2-5 g per 1 liter of water).
In the practice of dyeing wood, many use conventional dyes intended for dyeing cotton fabrics and furs. The strength of the solution depends on the intensity of staining; it is better to use a stain.
After dyeing, proceed to the transparent finish.
Who among us does not dream of surrounding ourselves with objects made of precious woods? For example, put a walnut table in the office. Or admire a mahogany bedroom set every day. Alas, not everyone can afford such pleasures - it is too expensive a pleasure. What about the rest? There is a way out: the most common spruce or birch can be disguised as valuable wood species. Here's how to do it.
Tools and materials:
- wood
- the necessary solutions (depending on the type of wood, described below)
- gauze for tampon, spray bottle
- skin
Process:
1. First of all, we determine what exactly it is possible to decorate your product.
- alder, elm, ash, beech, cedar, birch, cherry and pear can be imitated well under mahogany
- birch, oak, maple, hornbeam, apple, plum and cherry can be turned into ebony
- alder, birch, linden and beech are easily camouflaged under the walnut
2. We select special solutions with which we will impregnate the wood. For each type of tree - its own compositions.
- "Nutty": potassium dichromate (concentration 1:25) and potassium permanganate (concentration 2:25)
- Ebony look: aniline chloride (1:50 concentration), copper chloride (2:50 concentration) and potassium dichromate (3:25 concentration)
- "Mahogany": copper sulfate (concentration 1: 10-50) and yellow blood salt (concentration 2: 100)
The paint will fix better if you add a little (up to 3%) wood glue to the solution.
3. Prepare the surface for painting. We carefully sand the surface of the wood. There should be no traces of old paint, dirty and greasy stains, glue or varnish on it. Be sure to clean the coniferous species of resin drips, and then rinse with a 10% solution of sodium hydroxide, gasoline, turpentine, alcohol or 10% sodium chloride solution.
4. We start processing. It is necessary to apply the compositions in a strict sequence:
- "Under the nut": first we apply the first solution, and after 10 minutes - the second
- "Under the ebony": first we apply a mixture of the first two solutions, and after 10 minutes - the third
- "Under the mahogany": we apply the first solution, and after it dries - the second
Try on a small piece of wood first before working on the entire item. You can impregnate the wood with the compounds with a swab made of gauze folded in several layers. If possible, you can immerse the wood in the solution. Or spray it with a spray bottle.
If after 15-20 minutes you do not get the desired color, the treatment can be repeated. However, remember that wood that is too dampened can crack easily.
5. Let the product dry and enjoy the beauty!
(based on the book by A.M. Konovalenko)
COLORING WOOD
Process technology... Wood of different species takes on color in different ways. It has been noticed that hard, dense rocks are colored better than soft ones. So, oak is colored better than linden, and birch is better than beech, etc. Usually light wood is painted in more saturated colors; sometimes, wanting to enhance the tone, it is etched in special solutions. The material to be dyed is freed from stains and dust.
Wood dyeing can be superficial and deep, and in intensity - rich and weak. Mosaists mainly use deep dyeing, because during drying and grinding, part of the surface layer is lost and the texture lightens.
Since most of the chemicals used for dyeing are poisonous, certain precautions must be taken when working with them: wear rubber (surgical) gloves, protect your eyes with glasses, etch veneer in special trays, away from food and in a ventilated area. Pickling utensils should be enameled, glass and plastic trays. Usually, for this, photo baths of various capacities are purchased (the recommended sizes are 50X60 and 50X100 cm).
Several sheets of material of the same rock are dipped into the solution. It is not recommended to mix different types of wood in one solution. For better wetting in the solution, the veneer sheets are washed with water at room temperature before lowering into the bath.
Usually stained in a cold (room temperature) solution. Sometimes, to speed up the dyeing, the solution is heated or even boiled. Basically, this is how soft rocks are stained (for this they use galvanized dishes with a lid), which are kept in a solution over low heat for 2 hours.
With the cold method of dyeing, the colors are stable, monochromatic; when boiled, some dyes decompose and their color changes. With hot etching, it is easy to mistake the boil time. To determine exactly how deeply the veneer is stained, it is taken out of the solution with tweezers, rinsed in running water and, breaking off a piece, inspect the color of the cut.
With the cold method of dyeing wood, preference is given to natural dyes. Coloring pigments of natural dyes are lightfast and do not decompose; when using such dyes, the formation of spotting on the surface of the wood is excluded. The decisive factors for a high-quality color are the holding time of the wood in the solution and its concentration.
If the solution is of low concentration and the veneer is not etched, it is necessary to increase its concentration and reduce the time for impregnation.
For both cold and hot dyeing, it is recommended to place veneer sheets in a tray on a metal support (mesh), since the bottom of the tray usually contains a precipitate of dye and impurities that veil the veneer texture.
The purity and uniformity of the color is greatly influenced by the preliminary preparation of the material. To obtain the purest and brightest shades, sliced veneer sheets and some parts are bleached and de-resinated before painting.
After dyeing, the veneer is washed in running water and dried, periodically turning the sheets, in a clean room, where direct sunlight does not penetrate. When the veneer is almost dry, it is placed under a load to relieve internal stress. To find out the final color, before cutting out the elements for the set, a piece of etched veneer is varnished and allowed to dry. The used solutions are filtered and stored in a dark place in a closed glass container.
Effect of tannins on color... Coloring is intense only when the breed has enough tannins, of which tannin should be isolated first. In order for the wood to take on color, it is saturated with tannins. Combining with metal salts, tannins give it a color of a certain tone. Sometimes low concentration pyrogallic acid (0.2 ... 0.5%) is used to saturate wood with tannins.
Many tannins are found in willow bark. Wood of such species as oak, beech, walnut, etc. has enough of these substances. Oak bark is the richest in tannin at the age of 20 years. Tannins are collected in the bark of the trunk and on the branches, but they are especially abundant in the growths on the oak leaves - galls. In such balls with a diameter of 10 ... 15 mm, up to 60% of tannin is collected. The presence of tannin in the tree is evidenced by the color of the leaves acquired by them in the fall.
To saturate wood containing little tannins with tannin, enamel dishes are used, where veneer and crushed galls are placed (1/3 to the mass of wood). All are poured with water and boiled for 10 minutes. After that, the wood is taken out of the water, dried and moistened with mordant. If the bark of a young oak is used, then it is boiled for several minutes over medium heat, then the solution is allowed to cool and the wood is immersed in it. After a few hours, the veneer sheets, after rinsing in clean running water, are placed in a solution of a metal salt necessary to paint the material in the desired color. At regular intervals, the saturation of the tone is monitored visually. Wood of maple, birch, hornbeam, pear, apple, chestnut wood perceives the color best.
Pure tannin is a yellowish powder, easily soluble in water and alcohol.
Like the bark of young oak, tannin is sold in pharmacies and shops, etc. Most of the chemicals recommended for coloring can be bought in these stores. Some of them can also be purchased at the store and hardware stores.
To determine if there are tannins in the wood, drop a 5% solution of ferrous sulfate on a separate piece of it. If there are no tannins, the wood will be clean after drying; if tannins are present, a black or gray stain will remain on the wood.
You can speed up the drying of painted veneers by ironing. To do this, set the temperature regulator of the iron to the extreme right position and iron through gauze first one side, then the other, and so on until the sheet is evened out. Do the ironing without undue pressure, but confidently and quickly. When the edges of the veneer begin to lift, flip it over to the other side. If you miss this moment and the veneer sheet curls up into a tube, so that it straightens, soak it in water and continue ironing.
It is recommended to imitate maple, hornbeam, pear, plum under ebony, under mahogany - birch, beech, elm, pear, alder, maple, chestnut, walnut, cherry, under walnut - birch, white maple.
DYES AND SPRAYS
Dyes and stains are used for transparent finishing of joinery and semi-finished wood products. They go on sale in the form of powders, soluble in water or alcohol. To one degree or another, dyes are lightfast, bright in color, highly penetrating into the pores of wood, and easy solubility. Dyes for transparent finishes are of artificial and natural origin.
Synthetic dyes... Artificial (synthetic) dyes are complex organic substances obtained from coal tar. They can be water- and alcohol-soluble. Acid dyes and nigrosines are mainly used for transparent finishes.
A water-soluble dye is prepared as follows: hot (up to 90 ° C) boiled water is added to the powder in the required amount (according to the annotation on the package), stirring the contents and making sure that no powder clots remain in the solution. Then, to the set volume, boiled water is added to the mass again and everything is thoroughly mixed. With poor solubility of the dye, the solution is heated (without boiling), softening it by adding a solution of 0.1 ... 0.5% soda ash. For a smoother and deeper dyeing, it is recommended to inject a 25% solution of ammonia (ammonia) into the working solution in a volume not exceeding 4% of the total volume of the solution.
Of the water-soluble dyes, one can single out those that imitate wood for valuable species. So, for dyeing in the tone of mahogany, acid dyes are used - dark red, red-brown No. 1,2, 3, 4, as well as red No. 124. Dyes No. 1 and 4 give the wood a red-yellow tint, the rest - the color of a natural mahogany light to medium tones. For dyeing to match a light walnut, the following dyes are used: light brown No. 5 and 7, which give the wood, respectively, golden and yellowish tints; acid yellow, giving a lemon tint; yellowish-brown No. 10 and orange-brown No. 122, imparting yellowish and orange hues, respectively. The medium tone of the walnut is given by such dyes as acid brown (reddish tint), nut brown No. 11, 12, 13, 14, 16 (from reddish in the first to yellowish in the last issue), etc. For coloring the walnut in dark tones dark brown dyes No. 5 (grayish tint) and No. 8, 9 (reddish and lilac shades, respectively) are used.
Alcohol-soluble dyes are intended for dyeing wood and furniture varnishes. In appearance, these are powders of brown and red colors of various saturations, which dissolve in alcohol and acetone. The most commonly used red lightfast dye No. 2 (gives a pure red tone), reddish brown No. 33 (brown tone with a reddish tint), nut-brown lightfast No. 34 (even dark brown tone).
Acidic dyes give clear and lightfast colors. Without coming into contact with the cellulose fiber of the wood, the dye dyes the tannins and lignin present in it. While dissolving the acidic dye powder, a small amount of acetic acid is added to the aqueous solution. Before painting, the wood is treated with a 0.5% solution of chromopic or copper sulfate. The acid dye solution should be 0.5 ... 2% concentration.
When dyeing wood, it should be borne in mind that in the process of sanding the top layer of paint is removed. At the same time, the dye veil is removed. The disadvantage of water-soluble synthetic dyes is the raising of the pile on the painted surface, which requires additional sanding of the surface after drying.
Synthetic dyes produce bright and clear colors, so their use in mosaic woodwork is limited.
Nigrosines color the wood in black and bluish-black tones. They are mainly used for the preparation of coloring alcohol varnishes and varnishes.
Mordants include dyes and metal salts that come into contact with tannins. When etching, the wood is stained to a considerable depth in the solid wood mass and gives a through staining of the veneer. The color tone of the wood depends on the type of stain and the presence of tannins in the breed (see table). So, birch is imitated by gray maple; ash, beech, elm, cherry, alder, pear - under mahogany; apple, hornbeam, plum, walnut, white maple, oak, beech and pear - ebony, etc.
Breeds that do not have tannins are subject to saturation with them. For saturation, tanning extract is used, as well as resorcinol, pyrogallol, pyrocatechol, etc. If there is no tanning extract, a solution is prepared from oak sawdust and young oak bark
Table. Wood pickling solutions
Wood species | Mordant | Solution concentration,% | The resulting color tone |
Wood staining |
|||
Potassium permanganate | Brown |
||
Potassium dichromate | Light brown |
||
Chlorine copper | Bluish gray |
||
inkstone | Light brown |
||
Brown * |
|||
Oak extract (first application); | |||
iron vitriol (second application) | |||
inkstone | |||
Potassium dichromate | Brown ** |
||
inkstone | Light bluish gray |
||
Larch, pine | Resorcinol (first application); | Brown * |
|
Potassium dichromate (second application) | |||
Staining sliced veneer *** |
|||
Larch, oak | Sodium nitrite | ||
Pyrocatechol (saturation); | Under bog oak |
||
iron sulfate (impregnation) | |||
* Second application - 2 ... 3 hours after the first.
** Potassium dichromate is applied twice; the second application - after 10 minutes. after the first
*** The solution impregnates the entire pack of veneer.
The mordants are prepared by dissolving crystals of chemicals in water up to 70 ° C. When staining with mordants, wood (or planing veneer) is dipped in a solution. With a significant size of the painted surface, the solution is applied with a brush. The staining of wood does not give a veil, and the thickness of the color is uniform.
Natural dyes... Commercially available under the general name stains or stains. Stain is a powder, and stain is a ready-to-use aqueous or alcoholic solution of the required concentration. Dyes here are humic acids, which color the surface of the wood to a depth of 1 ... 2 mm. Stains and stains are surface dyes.
Natural dyes are resistant to light. They have a calm noble shade, do not darken the texture, are unpretentious in preparation, convenient for storage, and non-toxic. They are prepared from plants, tree bark, sawdust, etc. in the form of decoctions.
All natural dyes can be used for solid wood, mainly hardwoods - oak, beech, maple, ash, birch, etc. For this, the product is well sanded and placed with some bias towards the plane. The dye is applied with a flute, first across the fibers, then along. Reapply the dye only after the previous layer has completely dried. Dry products or objects away from batteries; they must not be exposed to direct sunlight. After drying, the product is wiped with a cloth and covered with wax mastic or varnished to fix the color.
Light wood can be dyed red-brown with a decoction of onion husks, yellow - from unripe buckthorn fruits, brown - from apple bark and walnut shells. If you add alum to each of the above broths, then the color tone will increase. Light wood (mostly hardwood) can be painted black with a decoction of alder or willow bark.
Light wood planed veneer can be dyed yellow using a decoction of barberry root. Strain the broth, add 2% alum to it and heat again to a boil. The cooled broth will be ready for use.
An orange color is obtained when using a decoction of young poplar shoots with an admixture of alum. To obtain a decoction of a poplar branch (150 g), boil it in 1 liter of water to which alum has been added for 1 hour. Then filter the broth several times and leave to settle in an open glass container. Leave it in a bright room for a week. After that, it takes on a golden yellow color.
To obtain a greenish color, add a decoction of oak bark to the decoction of young shoots of poplar with alum (see above). A greenish color will turn out if the fine powder of copperhead (50 ... 60 g) is dissolved in vinegar, and the solution is boiled for 10 ... 15 minutes. Soak the planed veneer in a hot solution.
To obtain a black color, mix the juice of privet fruits (wolf berries) with acids, for brown - with vitriol, blue - with baking soda, scarlet - with Glauber's salt, green - with potash.
In a solution of potassium permanganate (potassium permanganate), the color of the wood will first be cherry, then brown.
Yellow color is obtained by veneer made of light wood in a solution of potassium chloride (10 g per 1 liter of water at 100 ° C).
Gray, blue and black colors can be obtained by soaking sliced veneers in an infusion of oak sawdust and metal powder (or sawdust). Prepare the solution according to the color saturation. Soak the veneer in it for 5 ... 6 days. If there is no sawdust, you can use oak and metal shavings.
The blue-black color of bog oak is obtained by steeping oak veneer in a solution of metal shavings in wood vinegar.
Pour nitric acid or (a mixture of hydrochloric and nitric acids) and water into a glass container. Pour in acid first, then water in a 1: 1 ratio. Add 1/6 part by weight of iron shavings (sawdust) to this solution. The sawdust should dissolve over time. Add 1/2 part by weight of water again. Put the solution in a warm place for two days, then pour the light part into a glass dish with a ground stopper. In this solution, the oak will be colored under, and all other species will be gray.
If a birch or maple is covered with a solution of pyrogallic acid and, after allowing it to dry, cover with an aqueous solution of potassium chromium, you get a blue color.
Pour metal shavings into the wood vinegar. Close the dishes tightly with a ground stopper or lid and place in a warm place. After a while, the solution can be used as wood-acetic acid iron. In a mixture with sulfamine, such a freshly prepared solution gives wood a green color, and with acetic acid cobalt - a yellow-red color.
Dilute nitric acid with water and add copper filings. As you heat this mixture to a boil, you will notice that the sawdust has dissolved. Dilute the cooled composition with water again (1: 1); you will receive the finished dye. Sliced veneer sheets will turn blue in it. After soaking, the wood should be neutralized with a baking soda solution.
Grind 50 ... 60 g of copperhead into powder, which then dissolve in a small amount of vinegar. Add 25 ... 30 g of ferrous sulfate to the solution and add 2 liters of water to it. Boil the composition for 0.5 h. You will get a green solution, which should be used hot
Dissolve crystals of potassium dichromate in sulfuric acid and add water there (1: 1). In such a solution, the rocks will turn yellow, and if tannins are present in the wood, brown.
Dissolve crystals of copper sulfate in water and add chromopotassium to the solution. The wood will turn brown, and if tannins are present, black.
The golden brown color of birch veneer can be obtained by applying a 3.5% solution of potassium permanganate. If you pickle birch veneer with yellow blood salt in a solution of the same concentration, you get a birch that looks like mahogany. A 0.1% solution of nigrosine paints common birch gray.
Place pieces of steel wire or nails in the vinegar and after a few days you will get a dye with an effect.
Walnut wood contains a sufficient amount of tannins, therefore it is often used to obtain (by staining in solutions) other color shades, including black. In a container large enough to accommodate veneer sheets of a certain size, pour rainwater along with iron filings covered with a layer of rust. Soak the veneer in such a solution for a week, otherwise stable, through dyeing will not occur. After soaking, rinse the material in clean water, rinsing off unnecessary veil, and blot with newspaper and dry.
For dyeing walnuts black, you can use solutions of synthetic paints mixed with metal salts (for example, with copper chloride).
The fastest way to get a black tone in wood is to dip the veneer in a solution of acetic acid (or vinegar) with added rust. The veneer should be soaked in such a solution for 24 hours. Neutralize veneer sheets with baking soda solution before drying.
In some cases, for mosaic work, it is necessary to choose a silver or gray color of the sliced veneer. To do this, fill the iron filings with rainwater. Place the planed veneer on the edge so that the sheets do not come into contact with the bottom or sides of the cookware. It is best to get these shades on light breeds, rich in tannins.
To get a silvery gray color with staining, add vinegar (1: 1) to rainwater, place rusty nails or wire in this solution. After the solution has settled, dip the veneer into it. Control the desired color visually.
A silvery tone with a bluish-greenish tint can be obtained by soaking an ordinary birch veneer in a solution of sulfuric acid iron (50 g per 1 liter of water) for 1 ... 3 days. After soaking, rinse the veneer sheets with running water. Control the saturation visually. Stained walnut in such a solution has a smoky, grayish tint, and beech is brown.
A beautiful brown color can be obtained by subjecting the wood to ammonia vapor. Place the part to be painted in an enamel or glass dish and put an open jar of ammonia there. Close the dishes tightly on top. The process will be over in a few hours. With this method of painting, the parts do not warp, and the pile does not rise.
Some wood species acquire a permanent color under the action of acids. For spruce and ash, a solution of nitric acid in water (in equal parts by weight) is recommended. After being in such a solution, the veneer acquires a beautiful reddish-yellow color. After drying, sand the surface with a fine-grained sandpaper and smooth with horsehair, seaweed, bast or dry, non-resinous fine shavings.
Completely unexpected shades of color combinations are obtained in a decoction of ground coffee beans with the addition of baking soda. Before soaking in such a broth, pickle the sliced veneer in a hot solution of alum.
Plants are sources of many natural dyes. To paint veneer in them, a solution of strong concentration should be prepared. In order for the color to be stable, the veneer is first etched in a saline solution. For this, light-colored softwood veneer is selected.
If the veneer is kept in a solution of alum, and then dipped in an infusion of onion peel, it will turn yellowish-red.
The veneer, aged in a solution of ferrous sulfate, turns olive green. If, after that, it is dipped into an infusion of a decoction of birch leaves and fruits, then it will acquire a dark gray color with a greenish tinge, and after the infusion of rhubarb root - a yellow-green color.
If the veneer is etched first in bismuth salt, and then kept in an infusion of sawdust and wild pear bark, we get a pleasant brown color. Ash bark will give the veneer after bismuth salt a dark blue color, and alder bark - dark red.
The veneer, aged in a solution of tin salts, and then in the infusion of leaves and stems of potatoes, turns lemon yellow, and in the infusion of hemp leaves - dark green.
RESINING AND WHITENING WOOD
Deresinization of wood is necessary to remove excess resin accumulations (especially in conifers), to remove grease stains from the surface, etc. Deresin and bleaching are often carried out at the same time.
Typical formulations for resin removal are various solvents. So, for pine, a 25% solution of technical acetone is used. The composition is applied with a brush. After demineralization, the wood is washed with warm water and dried or bleached. Sometimes the wood is degummed with alcohol.
The following composition is widespread (g per 1 liter of hot water): baking soda - 40 ... 50, potash - 50, soap flakes - 25 ... 40, alcohol - 10, acetone - 200. Deresin with a hot solution using a flute. After demineralization, the wood is washed with clean water and dried.
With the help of bleaching, you can not only prepare the wood for coloring, but also achieve expressive tone, weakening it to the required level. Some wood species, when bleached, sometimes acquire the most unexpected color shades For example, a walnut, which has a uniform surface texture with a purple tint, when bleached in hydrogen peroxide acquires a pure scarlet-pink hue, with further bleaching - a pale pink.
Various solutions are used for bleaching. Some of them are fast, others are slow. The bleaching technology depends on the composition of the bleach. It is recommended to bleach the surface of the product before veneering or before cutting into the mosaic set, since bleach solutions (mainly acids) can affect the adhesion strength, and the veneer will peel off from the base. Bleach solutions should not be used hot, they must first be cooled.
In the practice of amateur carpenters, a solution of oxalic acid (1.5 ... 6 g) in boiled water (100 g) is traditionally used. In such a solution, light breeds are well bleached - linden, birch, maple, light walnut, white poplar; other breeds have gray spots and dingy shades. After bleaching, the veneer sheets are washed with a solution, which simultaneously raises the pile and removes the resin from the surface. The composition of the solution (in parts by weight): bleach - 15, soda ash - 3, hot water - 100. First dissolve the baking soda, then add bleach when the solution cools down. After applying the solution, the wood is washed with water.
For many species, with the exception of oak, rosewood, lemon tree and some others, hydrogen peroxide (25% solution) is an effective bleaching agent, which is sold in pharmacies as a solution or tablets of perhydrol. After bleaching with hydrogen peroxide, the wood does not need to be washed.
If a 25% aqueous ammonia solution is added to hydrogen peroxide to activate the process, the bleaching rate will increase significantly. Such species as birch, maple, beech, walnut, vavona, etc., this composition whitens within 15 ... 30 minutes. In this case, the solution is sometimes heated to a high temperature. In this case, bleaching is carried out in thick-walled bakelite trays, in thick glass trays or in enamel dishes. In this case, the trays cannot be used, as they can warp or melt.
It is necessary to bleach wood in a ventilated area. In this case, clothes should be covered with a rubberized apron, rubber gloves should be put on your hands, and your eyes should be protected with glasses. The solutions should be kept out of the reach of children, in a special cabinet, locked with a key. Pieces of wood in the tray should be turned over by removing and lowering them again. The whitening process is controlled only visually.
Hydrogen peroxide bleaches mainly fine-pored rocks and ash. Species containing tannins are difficult to bleach or not bleached at all in hydrogen peroxide (for example, oak). To speed up the bleaching process, the surface of such rocks must be moistened with a 10% solution of ammonia.
For accelerated bleaching, you can use a composition of solutions of sulfuric acid (20 g), oxalic acid (15 g) and sodium peroxide (25 g per 1 liter of water).
If you dissolve 40 g of potash and 150 g of bleach in 1 liter of pure water, you get another bleaching composition. Shake the mixture before use.
The best bleaching agent is titanium peroxide.
After bleaching in a 3 ... 5% solution of oxalic acid, birch wood acquires a greenish tint.
Oak and ash veneers are bleached with oxalic acid. For other types of wood, citric or acetic acid is used. For this, the acids are diluted with water in a ratio of 50 g per 1 liter of water.
To obtain a gold-like veneer, soak the Anatolian walnut in hydrogen peroxide, visually observing the appearance of the desired shade. Hydrogen peroxide must be at least 15% concentration. In the same way, you can get a pink color, discoloring some varieties of walnuts in hydrogen peroxide of 30% concentration.
To get a blueness on a white background, bleach a walnut with contrasting tones in a solution of hydrogen peroxide.
The structure of pine, birch, maple, aspen and linden is very similar to the structure of mahogany, walnut, oak, beech. For many years this observation has allowed cabinetmakers to create true masterpieces from inexpensive wood, which is always at hand, by modifying the available material into a noble and respectable one with a brush. The main thing for imitation is to choose the right dye.
Hard nut
Walnut wood attracts with its richness of shades and wavy stains. To imitate the pattern of walnut fibers, you need to have several basic shades of wood stains: rich gray-brown, light brown ("coffee with milk") and yellow-brown.
Walnut has a dark brown heartwood with gray tints. This color, through light brown and dark, turns into a yellow-brown sapwood.
It often happens that the fibers intertwine and dark streaks form in the light layers. All three shades are applied without drying, with one brush, alternating and intertwining with each other. You should not go through the same places several times.
Red tree
Mahogany has a wide range of shades, from pale pink to purple or nut red. It is not difficult to imitate this breed. The texture of mahogany is simple and, as a rule, fairly evenly colored, with smooth gradations of tones. But there are exceptions: some mahogany species have a special texture, with strictly alternating bright paths, which is difficult to confuse with others.
To simulate, you need to divide the color of the stain into two solutions, so that one is brighter than the other. First, a light tone is applied to the wood, then a second, more saturated shade is applied with a brush on a wet surface. It should be applied in parallel stripes at short intervals. If the workpiece has been well sanded, the layers of texture will shimmer and look like real ones under the varnish.
Tom on the oak
Oak wood can be imitated on a tangential cut of pine (the plane of such a cut runs tangentially to the annual layer), where the texture is more twisted and there are no straight layers that give out the species.
First, you need to process the workpiece along the fibers with a hand-held metal brush with a thin nap. On the soft layers, a tubular microstructure is formed, similar to that of oak wood. The desired shade is given by a solution of ferrous sulfate or industrial stains of the desired shades.
The color and texture of wood depends primarily on its species. However, the color can be changed if necessary using special dyes. The quality of the imitation depends not only on the dyes, but also on the treated wood.
To imitate valuable wood, various dye solutions are used that easily penetrate the wood. The most famous of them are walnut stain, stains No. 10. For coloring various wood species in different colors, as well as to imitate valuable wood species, you can use the following compositions.
To color the wood of pine, spruce, birch and beech brown, you need to take 3 g of acidic chrome brown dye, 3 g of vinegar essence and 10 g of aluminum alum per 1 liter of water.
For staining birch and beech wood under mahogany, two solutions are prepared: 50 g of copper sulfate per 1 liter of water and 100 g of yellow blood salt per 1 liter of water; initially, the surface is treated with a solution of copper sulfate, then it is kept for 10 minutes and a solution of yellow blood salt is applied.
You can paint birch wood like a walnut using 20 g of walnut stain and 2 g of stain No. 10 per 1 liter of water.
For staining under the old oak, you need 16 g of potash, 20 g of dry brown aniline paint. 20 g of dry blue paint is dissolved in 0.5 l of water, the mixture is boiled for 20-30 minutes, after which 1 teaspoon of vinegar is added; the surface is covered with a hot solution with a brush.
If painted under gray oak, then the treated oak wood surface is first coated with black alcohol varnish, and when the varnish dries, silver powder (aluminum powder) is poured onto the surface. Then, rub the powder into the pores of the oak with a clean swab. The remains of the silver powder are removed from the surface with a clean swab after about 1 hour.
The powder remaining in the pores of the wood is lightly glued with varnish, and gray hair appears on the oak. The dried painted surface is wiped along the fibers with a lump of horsehair or wood shavings, then covered with a colorless alcohol or oil varnish.
The following industrial water-soluble wood stains can be used to simulate fine woods.
Dye No. 1: reddish brown, used for dyeing beech mahogany.
Dyes No. 5, 6 and 7: light brown, used for dyeing beech and ash under a light walnut, for dyeing walnut, birch and ash.
Dye No. 10: yellowish-brown, used for dyeing birch and ash to look like a walnut.
Dyes No. 11, 12, 13, 14: walnut brown, used for dyeing birch, ash and beech for medium and dark walnut.
Dye No. 17: light brown, used for dyeing birch and beech for a medium-tone walnut.
Dye No. 122: orange-brown, used for dyeing birch and ash-like walnut.
Dye No. 124: red, used for dyeing birch, oak and beech mahogany.
Water-soluble dyes are prepared as follows: the required amount of dye is weighed out, dissolved in a small volume of hot water (at least 95 ° C) and mixed thoroughly. The resulting mass is poured into hot water and mixed.
The dye solution is allowed to stand for 48 hours, then filtered through two layers of gauze and applied to the product with a swab, brush or spray. The dye solution can have different concentrations depending on the desired color tone.
From the book: Korshever N.G.Wood and glass works
