THE TRADITIONAL WAY
THE COLORIZATION OF WOOD
by
John T. Kramer
Traditional Wood Conservator
P.O. BOX 8715
Sugar Creek, Missouri 64054
copyright 1989
I recently received a letter from Ralph A. Rowden of Mays
Landing, N.J. requesting more information about staining and
dyeing wood by traditional methods. So I will try to go into a
little more detail with this article. Remember test, test and
test again before committing any important work to any
methodology new or old.
Altering the color of wood is done by one of three basic
methods: Staining; Dyeing or Fuming.
Fuming is submitting the wood to an atmosphere of heat and
ammonia. Sheraton used this method to color sycamore a pearly
grey and called the result harewood. During the craftsman period
G. Stickley advocated this method for coloring oak a rich warm
brown. Split tonkin cane flyrods receive the dark brown
colorization by the same method. Commercially the work is done in
pressure tanks which are first flooded with water and raised to
boiling by external heat on the tank; the tanks are drained and
immediately filled with approximately 15 lbs. per square inch
pressure of anhydrous ammonia. The sealed tank is left for a
specified period of time (generally twenty-four hours) the
ammonia purged and the colored work removed. There are other
methods and techniques involving sometimes days and sometimes
short periods; the above is probably most common.
In order to fume wood in the small shop or at home will
require some experimentation and ingenuity. If the work is small
it may be possible to use capped sections of common pipe with
torches and commercial ammonia, much like preparing wood for
bending. Large pieces may be set in the back yard periodically
flooded with liquid ammonia and covered over with black plastic
to intensify the heat of the sun. It may be possible to use heat
guns or radiant heaters to benefit. I have read descriptions of
using the sun and plastic method in combination with fresh manure
to enhance absorption of the ammonia; be very careful this is
approaching basic explosives and may give your neighbors
something more than a bad smell to complain about.
What happens in fuming is the ammonia reacts with the
tannin in the wood and permanently changes the wood fiber. It
does provide very interesting colors and does not hide the figure
of the grain. Be careful and unless you know exactly what you are
doing stay away from anhydrous ammonia.
Staining is the most common method of changing the color
of wood because it is the easiest. It is also the least
satisfactory as the figure is hidden by the infusion of pigment
into the pores of the wood. Todays commercial stains for the
large part are simply thin paint washes that lay pigment on the
surface and really hide the beauty of wood. Adding pigment to
surface finishes has been done for centuries both to slightly
change color or to act as paint, enamel is nothing more than
heavily pigmented varnish.
Stain is of four general types; water base, alcohol base,
volatile oil base and oil base. Blend the required pigments with
the chosen medium to the color desired. Water is the least
penetrating, alcohol the quickest drying, volatile oil offers
best color density, and oil is the slowest drying. Oil bases are
generally cut with volatile oil. Turpentine is the preferred
volatile oil and Linseed the best for oil bases.
Pigments are generally minerals or oxides of minerals. The
most useful in staining wood are Van Dyke Brown, Yellow Ochre,
Red Ochre, Ivory Black, Raw and Burnt Sienna, Raw and Burnt
Umber, Zinc or Titanium White are the best choices to replace the
more efficacious White Lead. If you choose to work with the more
exotic colors be careful and first find out what you are working
with; i.e., Prussian Blue is the most beautiful blue you will
ever find and perhaps the last as it is a form of cyanide.
Dyeing is a chemical process that combines coloring matter
with mordants to alter the wood fibers. The French are attributed
to the first usage and developed many secret techniques based on
the plant materials used in the dyeing of fabric. In a previous
article there is a listing of many tree parts used in dying wood;
depending on the mordants used each tree part can produce several
different colors.
The most common dye we see is black rings on the tops of
oak tables used as plant stands. Iron (the mordant) is combined
in its oxide form with water which reacts with the tannin in the
wood. The only way to satisfactorily remove a mordant dye is with
a sour solvent, sour solvents are so dangerous to prepare and use
I can not in good conscience offer further instruction.
The most important part of dyeing is the choice and use of
the mordant. What will work with one specie of wood will not
necessarily work with any other specie. Not only the mordant but
the material the mordant is dissolved in will react differently
dependent on not only the wood but temperature, humidity and
particular coloring matter. The mordant is actually an
intermediate substance which combines with the wood to allow the
coloring matter to combine with it when the matter cannot combine
with the wood alone.
Mordants most often used are: Alum dissolved in sulphuric
acid. Acetite of alumine, prepared by pouring acetite of lead
into a solution of alum, which more easily saturates the wood and
imparts a richer and more permanent color. White oxide of tin is
used in three states; dissolved in nitro-muriatic acid, in
acetous acid and in a mixture of sulphuric and muriatic acid. The
form of tin most often used is nitro-muriate of tin prepared by
dissolving tin in dilute nitric acid to which sal ammoniac is
added. When used it is dissolved in a large quantity of water
with tartar. Red or yellow Oxide of Iron is not only used as a
mordant but, also as a coloring agent. Iron is used in two states
as sulphate of iron or copperas dissolved in water or more
commonly as acetite of iron which is prepared by dissolving the
oxide in vinegar, sour beer or pyroligneous acid; the longer it
is kept before use the better. Tan derived from an infusion of
nutgalls or sumac is often combined with other mordants like
alumine or oxide of iron to alter the resulting colors. There are
a great number of other materials suitable as mordants
additionally materials such as tartar, common salt, sal ammoniac,
sulphate of copper and many more are used to facilitate the
combination of the mordant with wood as well as to alter the
resultant color.
Most old wood dye receipts call for the wood (most often
veneers) to be boiled in the prepared substances. Experimentation
will provide you information as to which work more directly;
nearly all work best when layed on very hot.
The mordant, coloring matter, and additional chemicals
must be carefully chosen to combine intimately with the wood so
as to arrive at the desired color. In the course of these
articles I can do little more than to provide a point at which to
begin, it is up to each individual to experiment with what they
have available to meet their own needs.
Slight alteration of the balance of materials can have
noticeable effect on the end result. Cochineal with an aluminous
mordant will offer a crimson color used with oxide of iron it is
a black, when combined with alkanet root various shades of purple
can be derived. Logwood with volatile alkaline salts or acids
incline to purple, vegetable and nitrous acids render it pale,
while vitriolic and marine acids deepen it. Madder used in the
ratio of 16 parts to 5 parts alum and one part red tartar offers
a good red, if the alum is lessened and tartar increased it
becomes a red cinnamon, if the alum is eliminated it becomes
tawny cinnamon; volatile alkalies heighten the red color of the
madder, but, do make the dye fugitive. The vessel in which the
dye is prepared can effect the end result for example if boiled
in an iron pot the color will be quite different than if boiled
in a copper pot and different still if boiled in a tinned brass
pot.
Lime water can be helpful in dyeing browns and blacks when
the color does not want to come. Alum and tartar boiled together
and applied very hot to form a mastic in the pores of the wood
when cold can aid development of reds, yellows and other colors
that refuse to take. The water used has a marked effect on the
resulting color: snow water has a little muriate of lime and
slight traces of nitrate of lime, rain water has the same salts
in larger quantity along with carbonic acid, spring water
contains carbonate of lime - muriate of lime - muriate of soda or
carbonate of soda, river water has the same substances in less
abundance, well water contains sulphate of lime or nitrate of
potash in addition to the above named salts, pollution offers a
rich abundance of chemical substances in addition to those
listed, tap water has even more chemicals added. In order to
control colors the waters used must be consistent in chemical
composition: neutralize salts with acids, and mineral acids with
alkalis.
A few of the principal dyeing materials are alum, argol,
tartar, green copperas, verdigris, blue vitriol, roche alum,
quereitron, oak bark, fenugreek, logwood, fustic, brazil wood,
braziletto, camwood, brimstone, barwood, peach wood, sumach,
galls, weld, madder, safflower, green wood, annatto, tumeric,
archil, cudbear, potato flowers, dragons blood, oxides of iron,
lime, cochineal, lac cake, goldenseal root, lac dye, indigo,
onion skin, walnut husks, and nearly anything else you can think
of.
The woods most often used for dyeing are pear, holly,
beach, and boxwood. The wood is best dyed when as fresh as
possible after cutting with little to no aging. When dyed air dry
only; not with any added heat of fire or kiln, which will harm
the color. Before beginning to dye soak the wood four or five
days in clear water changing the water daily, observe above
comments about the chemical composition of water. Let the wood
dry about twelve hours before applying the dye. If these
instructions are followed the dye will strike quicker and the
colors will be more brilliant.
MAHOGANY COLORS
1. Boil together Brazil wood and roman alum with a little
potash.
2. Dissolve two ounces of dragons blood in one quart of
rectified spirits of wine in a warm place shaking frequently over
several days.
3. Boil one pound of logwood in four quarts of water. Add
a double handful of walnut peelings and boil again. Remove the
chips and add a pint of best vinegar.
BLACK
Rub the wood with aqua fortis a little diluted, remove
whiskers with pumice stone. Repeat the process and then rub the
wood with the following solution several times until density of
color is achieved. Polish with tripoli on a rubber of leather.
In a glazed earthen vessel combine a pint of strong
vinegar, two ounces of fine iron filings, and half a pound of
pounded galls. Allow the solution to infuse for four hours on hot
coals. Augment the fire and add four ounces of copperas and a
chopin of water with half an ounce of borax and half an ounce of
indigo; boil until a froth rises.
CRIMSON
Boil one pound of ground brazil wood in three quarts of
water for an hour; strain; add half an ounce of cochineal and
boil gently for half an hour.
PURPLE
Boil one pound of chip logwood in three quarts of water
for an hour; then add four ounces of pearl-ash and two ounces of
well pounded indigo.
YELLOW
Reduce four pounds of roots of barberry into dust by
sawing, put into a copper pan with four ounces of tumeric and
four gallons of water. Boil the wood in the solution for three
hours turning often. When cool add two ounces of aqua fortis.
GREEN
1. Proceed as with the yellow but instead of the aqua
fortis add as much of vitriolated indigo as will produce the
desired color.
2. To three pints of the strongest vinegar add four ounces
of the best verdigris ground fine, half an ounce of sap-green,
and half an ounce of indigo; strain.
RED
Boil the wood for three hours in two pounds of brazil-dust
to four gallons of water; cool; add two ounces of alum and two
ounces of aqua fortis, keep lukewarm until the color has struck
through.
BLUE
Put four ounces of indigo into a glass bottle with a pound
of oil of vitriol.