The art of mordanting and staining and the complete treatment of wood surfaces

Preface

Since the appearance of the Fifth Edition of this work in 1908, it has again been considerably enlarged and revised and the results incorporated in the present Sixth Edition.

In the portion relating to staining, the chapter on Brown Stains, which occupy an important position in connection with modern furniture and fittings, has been completely revised and enlarged by the introduction of the new and practically-tested Special-Oak Stains, Anthracene Stains and Genuine-Mahogany Stains, which have been very favorably received.

Because of their lesser importance, the number of staining formulas for bright colors has been diminished, but these have been replaced by staining formulas for new products of greater fastness to light.

All suggestions and experiments since the last edition have been incorporated here. The Sample Card of colors (in the Supplement) has been made to correspond with the new formulas in the book.

The rapid distribution of five preceding editions has demonstrated the earnest patronage accorded me, and I now place this Sixth Edition with the public in full confidence that it will prove an authoritative adviser in all problems pertaining to wood-staining.

WILLIAM ZIMMERMANN.

Barmen, April, 1910.

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GENERAL CONTENTS

PAGE

The Art of Mordanting and Staining ..... 9

Advantages of Mordanting Wood as Compared with Body-Colors

Properties of a Good Wood Stain . . . . . .11

Fastness to Light and Air . . . • 13

Deep Penetration of the Stain into the Pulp of the Wood . .17

Preserving the Natural Marking of the Wood . . . • IQ

Spotless and Uniform Staining of Large Surfaces . . .20

Preliminary Treatment of the Wood before Staining . . .24

Preliminary Treatment with Linseed Oil . . . -24

Preliminary Treatment of the Wood with Arti-Equalizer . 25

Preliminary Treatment of Coniferous Woods with Benzoic Solutions before Staining ....... 27

Preliminary Treatment of Oak with Solution of Sodium Chloride, 27 Staining Cross-Grained Wood ....... 28

Removal of Surface Resin from Resinous Woods before Staining, 29 Preliminary Treatment of Wood already Oiled before Staining, 32 Simple Method of Using a Wood Stain and Certainty of its Result, 33 General Rules for Staining Wood ... . . . . -34

The Dissolving of Dyes and Chemicals . . -39

Simplified Method for Manufacture of Staining Solutions Ready

for Use. (Stock Solutions) ...... 40

Low Cost of Manufacturing the Staining Solutions . . . 44

Preservation of Dyes, Chemicals and Staining Solutions . . 45

SPECIAL CONTENTS

PAGE

A. Water Stains ....... 46

Brown Stains ........ 47

Antique Oak Imitations . . . .48

Fuming of Oak ........ 48

Intensified Antique Oak Staining . . -50

Antique Oak Staining with Grayish-Brown Tone . . 52

Darkening the Fumed Tone . . 52

Antique-Oak Staining of Woods Containing Little Tannin

by Means of Fuming . . . -53

Lightening the Fumed Stain • • • • • 54

Antique-Oak Imitations with Light-proof Water Stains 55

Preliminary Treatment of Oak Before Staining . 56

Antique Stains J. K. L. S. and M • • •■ 57

Old Oak Imitations with Light-proof Aniline Dyes (New- Brown Stains) ....... 59

Antique-Oak Staining of Woods with Prominent Marking

but Containing Little Tannin . .62

Walnut Imitations ........ 63

Walnut Imitation with Granular Walnut Stain . 63

Walnut Imitations with Permanganate of Potassium 64

Walnut Imitations with Aniline Dyes . . .66

Darkening of Natural Walnut Wood . 67

Rosewood Imitation ........ 67

PAGB

Mahogany Imitations ....... 68

Darkening the Natural Mahogany Wood . . .70

Unhealthy Effects of Potassium Chromate Stains . .71

Staining of Genuine Mahogany . , . . -72

Brown Staining with Light-proof, Acetous Aniline Dyes in

Modern Tones ....... 73

(a) Staining on Wood Containing Little Tannin . . 74

(b) Staining on Oak Wood ...... 78

Anthracene Stains .81

Method of Making Solutions of Anthracene Stains . . 82

(c) Anthracene Stains on Oak . . . .82

(d) Anthracene Stains for Woods Containing Little Tan-

nin 85

(e) Special-Oak Stains, Liquid, and Ready for Use . 87 Directions for Using the Special Oak Stains . . .88

Ebony Wood Imitations ........ 90

Staining Wood Gray . . . . . . . -91

Gray Staining of Woods Containing Tannin by Means of

Green Vitriol ....... 92

Gray Staining of Woods Containing Little Tannin by

Means of Green Vitriol . . . . .93

Gray Stains with Aniline Dyes and Combined Stains . 95 Staining Wood Red ........ 100

Yellow and Orange Stains ....... 102

Green and Olive Green Stains ...... 103

Blue and Violet Stains ........ 106

Water-proof and Washable Wood Stains (Oxidine Stains) 109

General Remarks Concerning Water-proof and Washable Wood Stains . . . . . . . .110

General Rules for the Use of Precipitate Stains . .111

Advantages of Precipitate Stains . . . .113

Precipitate Fumed Stains . . . . . -114

Precipitate Stains Whose Final Tone is Obtained by Successive Staining with Aqueous Solutions of Two Appropriate Chemicals . . . . .121

Sulphamine Stains

Black for All Kinds of Wood

B. Turpentine Stains and Turpentine Wax Stains

(a) Turpentine Stains .

(b) Turpentine Wax Stains

G. Alcohol Stains

127 129

The Staining of Shellacs, Mattings and Alcohol Varnishes

with Aniline Stains (Alcohol Stains) Soluble in Alcohol, 132

Formulas for Staining Shellacs, Alcohol Varnishes and Mattings 134

The Coloring of Wax . . . . . . 136

Process for Subsequent Covering of Unstained Pores of

Weights and Measures

The Art of Mordanting and Staining

At the great expositions recently held in Dresden, Nuremburg, Reichenburg (Bohemia) and in Berlin, it was demonstrated anew with what importance color is regarded as a factor of modern interior construction. Seldom, if ever before, have there been exhibited such simply-constructed rooms whose effect was obtained almost exclusively by color scheme.

Undoubtedly color is one of the strongest means of impressing the human mind. Through its agency may be produced an atmosphere of warmth and cheer or a contra effect of cold and repellency; a stately, dignified interior, or walls emanant of festive brightness. It is essentially a predominating force, and being also the cheapest auxiliary means of decoration, its practicability as applied to the dwelling rooms of those moderately circumstanced is highly evident.

Craftsmen, cabinet-makers, decorators, painters, and all whose calling is associated in some measure, great or small, with the use and application of stains and mordants, should be, as a matter of course, thoroughly familiar with the primary essentials of preparation, both of the surface to be stained and of the stain-composition itself, in order to achieve clever results.

The first attempts at staining our domestic uncolored woods a certain designated tone, were made with the object of imitating the magnificent and gorgeously-colored, but expensive, tropical woods; and also of staining the naturally light young wood the prized dark tone peculiar to old wood.

It is only recently that domestic uncolored woods have been stained all conceivable colors not inherent to the natural wood. When this new branch of cabinet-making had its inception a few years ago, and prominent artists and artisans offered their services, they suggested novelties other than the usual brown tones thus far used, with the intention of treating the entire room according to one designated color scheme.

The somewhat crass colors used at first, such as bright green, blue, etc., have, of course, given way to more subdued, intermediary tones, — faint blue-green, greenish-gray, gray-brown, etc.

Advantages of Mordanting Wood as Compared With Body- Colors and Glazing

Among experts and the intelligent public to-day, stained wood is in high favor, and to the art of wood-staining is therefore opened an ever-increasing field of application. The foundation of this method of coloring various objects and constructions of wood depends on that property common to all wood-staining, — of retaining and intensifying the natural texture and marking characteristic of each species.

That this requirement cannot be met by means of the formerly universal method of painting the wood with body colors is very evident, as all body-colors consist of insoluble materials which are applied with the help of proper binders, such as linseed-oil, varnish and turpentine in more or less thick coats. On account of their impermeability to light, as the very name implies, they cover the entire surface of the wood so completely that it is no longer possible to recognize its species.

The artificial graining subsequently executed with stencils and transfer-paper or by free-hand over this coating, does not deceive the eye; for even though an artist's handiwork, it is easily distinguishable from the natural wood grain.

If the coat of varnish subsequently applied to protect the glazing or graining color has been worn off in spots by repeated washing or otherwise, then this layer of color adhering only to the outer surface of the wood is soon worn away and the bare wood shows.

The new technics of wood mordanting, or wood staining, are based on entirely different principles.

The dyes or chemicals used are perfectly soluble in water or other solvents, such as turpentine or alcohol, so that these dyes and chemicals, penetrating with their solvents (water, turpentine, alcohol) up to a certain depth in wood, remain therein when the solvents evaporate, thus according a stained surface.

In many instances of wood-staining, the dye is actually generated (chemically) in the wood fiber and left there by means of the consecutive effect of two proper chemicals, or by the effect of chemicals on the tannic acid already in the wood.

In whatever manner the staining is done, whether by means of solutions of prepared stains, or by means of the reciprocal action of chemicals on each other, there is always an actual staining of the pulp of the wood up to the depth of one-half to three-fourths of a millimeter, to which the mordant solutions actually penetrate within the wood.

On this property of the stain, to penetrate into the pulp of the wood itself and to deposit there the dissolved stain, rests its capacity for sharply intensifying the structure of any kind of wood. The pulp of different kinds of wood is by no means of uniform hardness and density. In particular the annual rings in our domestic evergreens are always harder than the wood in between. But in the harder deciduous woods also, where the difference between the annual rings and the rest of the wood is not so marked, there are always differences in the density of separate parts of one and the same surface.

The penetrating capacity of the staining solutions is favorably or unfavorably influenced by these differences in density and hardness of the separate parts of one surface. In the softer parts of the wood the stain not only penetrates deeper, but greater quantities of it are absorbed than in the harder and denser portions. Hence in the softer parts of the wood there is a much greater amount of color deposited than in the harder parts, corresponding to the increased assimilation of the stain ; and after staining, these appear darker, generally showing a more tinged shading than the harder parts. This is especially characteristic of evergreens, such as firs, pines, pitch-pines, Carolina pines and yellow pines. By the various absorbent qualities of soft and hard parts in the same surface is to be explained the fact that the marking and silver grain of the wood, which are scarcely visible in its natural state, come into prominence after staining with an enhanced beauty due to the tinged shading.

Therefore it will be perceived that the staining of wood not only affords us a desired color effect, but presents unchanged the natural marking characteristic of each species. The process has taken its rank among the foremost arts of the day, and it is hoped to accord within these pages a comprehensive aid to its higher advancement and utmost perfection.

Properties of a Good Wood Stain

Because of the long periods of usage given woodstructures, we require of a stained wood in the first place, resistance to the effect of light and air. But this is not the only essential; there are a large number of chemicals and dyes which are very fast to light, and yet are not fitted for wood-staining.

A wood stain, to fulfil all requirements for use, in addition to its light-proof quality, must be easily and clearly soluble and remain clear in its solution; must penetrate deeply into the pulp of the wood, intensify strongly the natural marking, and when staining large surfaces, be uniform and spotless. Furthermore, its application must be simple, the result certain, and the cost to manufacture be low.

Fastness to Light and Air

The fading (bleaching) of all colors and dyed materials is caused by the usual effect of the sun's rays in conjunction with the oxygen in the air and the moisture always in the atmosphere. By the combined effect of these three agents all dyes are changed in a longer or shorter period of time into colorless substances, or else undergo decided changes in tone. This is true not only of wood stains, but also of all natural and artificial dyes in general ; therefore also for body-colors, glazing-colors and colors with which our clothing material is dyed or printed.

The French chemist, Chevreul, has shown experimentally that fading of dyes and dyed materials cannot occur in sunlight alone without the presence of air and moisture. But this knowledge has never been availed of up to the present time, as we have not been able to preserve our diversely stained, mordanted, glazed and painted wooden objects in an absolutely dry and air-free room. Therefore we have to reckon with the factor that in the course of time all colored objects change or lose entirely their original tone. Absolutely light-proof products are lacking both in natural as well as artificial dyes; however, the length of time required for light and air to work such thorough changes in dyed materials varies extraordinarily.

On the one hand, while we possess dyes which in a direct light totally change, or entirely lose their original tone after a few days, on the other hand there are a number of such products which resist a direct light for many months without any considerable change, and last many years practically unchanged in the exceedingly dry air of our dwellings and in the sunlight which is diffused in them.

The darkening and deadening of the natural or artificial coloring of the wood in furniture is by no means to be attributed to a change in the dye alone, but is due principally to a change in the ground-color of the wood. It is universally known that wood especially rich in tannin, such as oak, mahogany, and also walnut, darken very decidedly on account of the effect on the tannin in the wood by the ammonia always in the atmosphere, a phenomenon which is called the "aging of the wood."

But also woods with little tannin, such as fir, pitch-pine, maple, etc., lost their bright, natural color and become yellower and darker upon long exposure to light and air.

According to the length of time it takes for a decided change in the original tone of a colored object, due to the influence of light, air and moisture, are made the differentiations, — practically fast, medium fast, and fading, or fugitive colors.

While the artificial dyes in use commercially up to 1880 had very little fastness and had no general application to wood-staining, among the innumerable recent coal-tar derivatives we have a sufficient number of such dyes which not only equal the natural vegetable dyes in light-proof qualities, but in most instances far surpass them.

Among the two thousand and more artificial dyes used commercially to-day in the various factories, it is not easy to select those which are fast to light and air and are therefore adapted for wood staining. It requires a thorough knowledge of the properties of the various coal-tar dyes which only the specialist in this branch can have.

Unfortunately this most important requirement of fastness to light in a good wood stain was given very little attention until recently. About fifteen years ago, when men first concerned themselves with the achievement of stains in modern tones, fugitive dyes dating from the very first aniline period were deliberately used. Enjoyment of the results obtained was therefore short-lived, and it seemed probable that the new manner of modern wood-staining would perish in embryo; for once a more or less legitimate prejudice based on sad experience has settled on the purchasing public, the impression is lasting and cannot be dispelled until its deep-rooted effect has been overcome.

It would be unfair to place upon the cabinet-makers responsibility for bygone mistakes, for they could use only those dyes and wood stains for their work which were offered as available by the dye-works and wood-stain manufacturers, and these were almost, without exception, of decidedly inferior quality.

In general the following rules apply to the fastness to light of wood stains:

1 . With the chemicals and dyes available at the present time, water-stains can be made which satisfy all reasonable requirements as to fastness to light. But dyes absolutely fast to light cannot be made, either with natural vegetable dyes nor with artificial dyes.

2. As regards fastness to light, mineral dyes are much superior to vegetable dyes and aniline dyes, but they cannot be used for wood-staining because they are insoluble, and hence do not fulfil the basic requirement of penetrating into the fiber of the wood and maintaining the natural marking.

3. Alcohol stains, as well as turpentine and wax stains, usually have only a very medium fastness to light and do not equal the good water-stains in this respect. Among alcohol, turpentine and wax stains, gray and black stains are the most light-proof.

4. The capacity of a stained-wood surface to resist the effect of light is furthermore dependent on the intensity or the depth of the tone in each individual case. A dark tone is always faster than a medium, and the latter has more resistance than a light stain, if the same stain or the same dye is used in each instance. The following examples may demonstrate this : For Case I , stain one square meter of a certain kind of wood a very strong dark tone, so that lO grams of the dye are absorbed by the wood ; for Case 2, one square meter of the same wood with the same stain but in a lighter tone, so that only one gram of the dye is absorbed by the wood. Set both tests in the light simultaneously. In a certain length of time, due to the destructive effect of the sunlight, in conjunction with the air and moisture, a certain amount of the dye, say 0.5 gram, is dissipated. With the dark-stained wood 9.5 grams of the dye remain intact, so that the stained wood is only a trifle lighter (5%) and seems somewhat duller. With the light stain on the other hand, half of the dye (50%) is dissipated ; this seems very much faded and changed in tone, and yet in both cases the same stain has been used. This example shows us further that in making experiments in exposure to the sunlight, the same depth of color must always be used in order to obtain a conclusive decision concerning the respective fastness to light.

5. The layer of shellac, varnish or wax always covering stained wood, protects the stain from the effect of water, and prevents the penetration of rays of light only to a slight degree; hence delaying the dissipation of the dye by light but a trifle.*

6. If it is necessary to mix two or more shades to get a certain tone, only such colors should be chosen as possess practically the same fastness to light. For

, example, if an orange, fast to light, and a green, not fast to light, should be used for an olive-green stain, the green would fade in a short while and the stain would quickly change to orange, — that is, the stain would become discolored.

Every user of wood stains should possess an independent knowledge of their light-proof qualities and personally obtain the test by simultaneous exposure to light of small stained, shellacked or varnished boards. These comparative experiments must be made with equal conditions and during the months of May to September; for in the fall or winter months the sun's rays have little effect, and the experiments may very easily deceive. They should be conducted behind a pane of clear glass fixed obliquely toward the south, so that the sun's rays can fall as nearly as possible vertically on the stained surfaces. In determining the degree of fastness to light, the simultaneous exposure of a stain of recognized excellent fastness to light and of one which is not, is necessary in order to ascertain in which category the stain under exposure should be included.

In the description of individual stains, their power of resisting the effect of light will always be discussed in detail.

Deep Penetration of the Stain Into the Pulp of

the Wood

In applying the liquid stains, especially water-stains, the grain of the wood is more or less raised, and in order to facilitate a perfectly smooth surface, a thorough rubbing with curled hair should be given before the subsequent shellacking, matting, etc.

If the stain does not penetrate deeply and the wood is only surface stained, it is easily rubbed through, especially at the edges, exposing the raw wood in spots. This untoward occurrence is usually to be feared if the wood has been subjected to some quick polisher, such as sandpaper, etc., applied under too great pressure.

Rubbing through is avoidable by the following precautionary measures:

I. Dampen surfaces to be stained with a very moist sponge, but do not rub until the pores have swelled and the grain is raised. Thoroughly sandpaper without pressure or scouring. Surfaces poUshed in this way have the grain raised very Httle when staining with water-stains. 2. For poUshing the mordanted surface use only horsehair or perfectly smooth sandpaper. The latter is preferable with large-pored woods like oak, as horsehair often dislodges the stain from the pores. (Only "00" sandpaper should be used, and that when it is worn so it no longer catches on wood.) The greater or lesser depth to which stain may penetrate into the pulp of the wood depends largely upon the density or hardness thereof. Obviously the liquid applied to hard wood cannot penetrate so deeply as in soft wood. A large amount of resin in the wood will also greatly impede the penetration of the staining solution because of its fatty elements. Thus the penetrating qualities of individual groups of stains are very diverse.

Alcohol stains penetrate deepest into the wood. Next in order come water-stains, and lastly the turpentine and turpentine-wax stains. The latter, however, always stain merely the surface of the wood. The following general rules are to be observed for obtaining the deepest possible mordanting of the wood:

1. The wood should be placed in a warm room several days before staining so that the pores will open and make possible a better penetration for the staining solution.

2. With hard woods the staining liquids are generally to be applied hot, as they penetrate deeper than when cold.

3. The stain should be applied with a well-saturated brush or sponge, so that the surface becomes quite wet. The liquid can then be left some time to penetrate into the wood before the application of the softening brush for evening the stained surface.

4. Resinous woods should be washed off before the staining or waxing with a solution of 50 grams of calcined soda (pulverized soda) in i liter of hot water; or very resinous woods with a soda acetone solution (for preparation and use, see pages 29-32). After the resin is removed the wood should be washed with warm water.

Preserving the Natural Marking of the Wood

An essential requirement of a good wood stain is that it shall preserve intact and intensify the natural marking characteristic of each kind of wood, whereby the layman may recognize its variety or species. To this single capacity of the stain is to be ascribed its almost universal use to-day as a finish for wooden constructions of general artistic utility.

Only a stain which has the property of being perfectly soluble in water or other solvent, and which contains no small particles in suspension, can penetrate into the fine pores of the wood and stain it without leaving a deposit on the surface partly concealing the marking.

For this reason all staining solutions which are not perfectly clear, or contain the slightest residue, should be filtered through cotton cloth before using, in order to remove all undissolved particles. These fine undissolved dyes or impurities settle in large-pored woods, such as oak, causing an unsightly punctured appearance, and cannot be removed, even with the most careful rubbing.

For the same reason all staining solutions which have the property of settling after long standing or of segregating from their solvent, must be brought into solution again before using, by warming or boiling, and filtered again.

The intensification of the texture and marking of the wood after staining is to be explained by the varying density and hardness of the wood itself. As already stated, in almost all woods there are hard and soft places. A greater quantity of liquid is absorbed by the soft parts, and after staining they appear darker than the hard parts, due to the latter's lesser absorption.

This is especially characteristic of pine, fir and pitch-pine, in which the annual rings always appear lighter stained than the rest of the wood.

If for any reason a decided intensification of the marking is not desired in these woods, the surface should be sponged off before staining with a solution of one part Arti-Equalizer, thinned with two to four parts hot water; rubbed after drying, and then stained.

Another method of obtaining a partial balance in the intensity of the tone in woods of very diverse hardness and density, consists in mordanting such surfaces very wet and immediately taking off the superfluous solution with a well-squeezed sponge before it has time to penetrate far into the soft parts of the wood. Previous rubbing of evergreen woods with one part raw linseed oil and one part turpentine before staining does good service in balancing the hard and soft annual rings, as the linseed oil taken up by the soft parts of the wood prevents too great absorption of the staining solution.

The glazing of wood with oil or water glazes (often falsely called stains by painters), has nothing in common with real wood-staining, as the glaze, which is an insoluble body-color, cannot penetrate nor even be rubbed into the wood, but rather is deposited on the surface, and so the marking of the wood never retains its original natural beauty.

Spotless and Uniform Staining of Large

Surfaces

A well-stained wood does not need such a uniformity of tone as is required in monochrome cloth. But on the other hand, as has already been mentioned in the previous chapter, an intensification of the marking by contrasting its light or dark coloring with the uniform surface is very effective. However, light or dark spots caused by faulty application of the staining solution, by resinous places or by undissolved or secreted bits of dye, are unsightly and troublesome. Naturally it is much more difficult to stain a large surface uniformly than a small one.

The wood itself is a very important factor toward the even application of stain. If it contains knots and sapwood, uniform staining is practically impossible. Because of its porous character, sap-wood absorbs a large quantity of the staining solution, which causes it to assume a considerably darker appearance and often a different color from that of the dense heart which takes up much less of the staining fluid. Oak wood is an exception in that the darker heart is always darker than the lighter sap-wood. Of course the sap-wood proper is not meant, as this must always be cut out because of its great liability to become worm-eaten. Also, knots and other defects in the wood are not covered up by staining as they are when coated with body-color, and therefore show plainly.

Irregularity of surface may be further caused by putting on the stain with a half-dry brush. The amount so applied is insufficient and too quickly absorbed by the wood, so that a subsequent balancing with the softening-brush is impracticable, as the strokes of the brush are then clearly visible.

The wood should always be stained as wet as possible in order to insure uniformity of tone.

The objection expressed by many cabinet-makers that this method tends to raise the grain more, is incorrect; for experience has shown that with meager applications of the staining solution the wood swells exactly as much as when it is applied very wet. When staining large areas, therefore, the following rules are strictly to be observed :

1 . The brush used should always be well saturated with the staining solution, so that as much as can be absorbed is applied to all parts of the wood, and it is, to a certain extent, super-saturated.

2. For large surfaces use a sponge or woolen cloth instead of a brush. Before applying the stain therewith, however, the sponge or cloth should itself be first immersed in the staining solution and well-squeezed, to thoroughly impregnate it with the color. Then saturate, and proceed as with brush.

3. Every stained surface, after the application of the solution, must be wiped off uniformly with a well-squeezed sponge or well-wrung woolen cloth, in order to remove any possible irregularities in the distribution of the stain over the entire surface, and also the surplus stain.