THE TRADITIONAL WAY

SELECTED SHOP FORMULAE

John T. Kramer

Traditional Wood Conservator

P.O. BOX 8715

Sugar Creek, Missouri 64054

First serial rights, one time use

International Woodworking magazine

VARNISH, SHELLAC & LACQUER

Within the United States (until after the mid-nineteenth century) there seems to be little historical difference between varnish, shellac and lacquer. In the orient lacquer was a specific formulation of highly toxic ingredients which required many years of ever increasing exposure for the worker to develop tolerance. Contemporary usage has most often differentiated varnish as a oil base finish and shellac as a spirit base finish but, as always, there are exceptions. Old journals often refer to shellac as varnish and vice-versa.

The method taught in manual arts classes of public schools during the second & third quarters of this century is sure to get a worker in trouble. Two to four coats of shellac sanded between coats as a filler followed by four to six coats of slow drying varnish rubbed out between coats with a variety of materials is slow, laborious, and fraught with problems. It can be elegant.

Oil varnish is made by dissolving the gums and resins chosen in heated oils (linseed preferred over sweet) turpentine is generally used as a thinner. It used to be that it was difficult to make an oil varnish of the quality one could purchase, now there is no other option. Fire hazard during manufacture is considerable.

Volatile Oil Varnish is made by dissolving gums and resins in, most often, oil of turpentine.

Spirit varnish is made of shellac, gums or resins dissolved in spirits of wine. They must be quickly applied as they dry very fast; when sprayed they dry almost instantly, but, extreme care must be taken with sprayed spirit finishes as fire can occur from the spraying equipment or from electric and gas appliances nearby. Good (dust free) ventilation is required when working with any surface finish.

Before applying any hard finish lay the dust in the area by dampening floors with water; after cleaning as well as possible. When using oil finishes protect from dust while drying.

To maximize results of any hard finish rub down each coat when dry with felt moistened with water and sprinkled with fine pumice or rottenstone. Use a clean well worn brush and protect from cold and damp.

Shellac is made from the exhudations of insects deposited on trees in the orient, collected and refined. It comes in several grades ranging from dark orange to clear, it is available ground and in button forms. Most traditional lacquer outside the orient was made from the clearest grades of shellac. Lacquer is now made from modified nitro-cellulose base; and aside from the fire and health hazards of application; is the most compatible with wood of any modern finish.

Varnish is made from natural tree gums and resins the best is made from Amber, Copal and Damar; mastic, elemi, animi, sanderac, tragacanth, rosin, balsam, benjamine, and others were also used. Varnish is now made from alkyd resins, a relative newcomer to finishing hence long term efficacy is still suspect, is entirely useless when compounded with plastic resins, but, at least of short term benefit when compounded with a truly conditioning primer and base. Enamel is nothing more than heavily pigmented varnish; if made for exterior application the recipe would include only the hard and tough resins in good proportion to prevailing climates of the area; and perhaps a little tung oil as a weather resister (this is the only known traditional use for tung oil and the only practical one).

Dissolving hard gums and resins requires several days in a warm place or in direct sunlight, this occasionally turns some of the oils a slight yellow color; which is oft desirable. Copal varnish applied to mahogany will produce a good golden-yellow color after a short time. If natural oils and waxes are first applied to the mahogony a rich red color will result; the deep purplish hue so often seen on old work is usually the result of cochineal and alkanet root used for pigmentation.

Stains, varnishes and shellac are intended to allow the beauty of the wood to show through; unlike most paints. Some maintenance is required to preserve the finish. Polishes, oils and preservatives all add to or detract from the natural chemical changes which cause "patina." Modern chemicals do not aid the permanence of appearance.

Old reciepts call for finishes, stains, oils, glues, putties &c. to be mixed up fresh. This may mean to use immediately after long periods of preparation up to a month or more.

Modern varnish, shellac and lacquer available at your paint store bear no relationship (other than name) to the traditional product and are primarily synthetic petro-chemicals. Even Spar varnish is today most often a synthetic. A few hard to find specialty suppliers do offer a few traditional shellacs and varnishes pre-mixed, though even these most often have synthetic oil, thinner and spirit bases.

A STANDARD RECIPE FOR SHELLAC OR VARNISH

1 part gum (resin or shellac)

2 parts alcohol

OIL VARNISH

1 part gum

1/2 to 1 part oil

2 parts turpentine

ca.1800

1 part sanderac

2 parts spirits of wine

Mix cold, shake frequently.

COPAL VARNISH

4 drams white rosin melted in a glazed vessel

2 oz. white amber finely powdered

Oil of turpentine to proper consistency

Pour in course linen bag and press out varnish.

BLACK VARNISH ca. 1817

4 oz. gum-lac

1 oz. sandarac

1 oz rosin

4 drams ivory black

sufficient spirits of wine

Melt and mix; strain through linen cloth.

GOOD VARNISH

1 part copal

1 part sandarac

1 part rosin

5 parts alcohol

COPAL VARNISH

Gum copal with equal parts linseed oil, spirits of turpentine, or alcohol.

JAPAN VARNISH

1 gal. boiled oil

8 oz. umber

3 oz. asphaltum

3 oz. oil of turpentine

VIOLIN VARNISH

1 gal. rectified spirits of wine

6 oz. gum sandarac

3 oz. gum mastic

1 gill turpentine varnish

Put the whole in a sealed tin can and set in a warm place twelve days shaking frequently intil disoolved. Strain and keep for use.

TURPENTINE VARNISH

1 gal. oil of turpentine

5 lbs. pwdered resin

Put in a tin pan on a stove and let boil one-half hour. Ready for use when cool.

PAINT FORMULAE

Ordinary traditional oil paint consists of five things;

1. a base of white lead, zinc white or red lead

2. a binder and vehicle generally linseed oil

3. a thinner generally turpentine

4. usually a drier

5. a pigment in addition to the base

The base, itself a pigment, gives body to the paint and protects the surface treated; the vehicle allows easy application of the base and provides further protection; the thinner makes the paint workable; the drier assists oxidation since drying of oil base paints does not mean evaporation; and the pigment imparts color.

Enamel is made from fine ground pigment with varnish as the vehicle. Shellacs and varnishes were often pigmented to provide translucent colors; when built up in many thin precise layers on a surface the popular "faux" finishes were achieved to make plain wood or plaster resemble fancy grained wood or marble.

MILK PAINT

2 qt. skim milk

8 oz. fresh slaked lime

6 oz. linseed oil

2 oz. white burgundy pitch

3 lbs. spanish white

Lime is to be slaked in water, exposed to air and 1/4 of the milk mixed in. The pitch is dissolved in the oil and added a little at a time, then the rest of the milk and finally the white.

ca. 1839

2 qt. skim milk

2 oz. fresh slaked lime

5 lbs. whiting

Put lime in a stoneware vessel and pour a sufficient quantity of milk on it to make a mixture resembling cream; then add remainder of milk. Spread crumbled whiting on surface and mix well. Any color pigment may be then added to suit the fancy.

ca. 1815

2 qt. skim milk

6 oz. slaked lime

4 oz. sweet oil

5 oz. spanish white

For outside use add:

2 oz. slaked lime

2 oz. oil

2 oz. white burgundy pitch

No other instructions were included with this reciept of ca. 1815

ca. 1828

Skimmed milk 4 lbs., or 1/2 gal.

Lime (newly slaked), 6 oz.

Neatsfoot oil, 1 gill

Color, 1 1/2 lbs.

For outside painting add:

Oil, 2 oz.

Turps, 2 oz.

Slaked Lime, 2 oz.

WHITEWASH ca. 1830

2 oz. alum

18 lbs. lime

2 1/2 lbs. fine ground wheat

2 gal. milk

9 gal. water

1/2 lb. ground hide glue

10 lbs. whitting

2 lbs. salt

For outdoors add:

1 qt. linseed oil, turpentine mix

CHEAP WHITEWASH

10 parts whiting

10 parts lime

1 part hide glue

1/8 part alum

water to consistency

Substitute linseed oil for 1/2 water when used outdoors.

MEDIUM CHEAP WHITEWASH

Mix glue size with whiting and paint on.

DIRT CHEAP WHITEWASH

Dissolve quick lime in cold water, stir till well mixed.

3 parts spanish brown

3/4 part whiting

2 parts linseed oil

2 parts turpentine

1 lb. spanish brown

1/2 lb. whiting

1 qt. linseed oil

1 qt. turpentine

DISTEMPER PAINTING

Now known as tempera paint made with milk, cheese or hide glue as the protein bonding agent. Substitute hide glue size and hot water for the oil, not as good as oil paint.

PUTTY

TRADITIONAL PUTTY

Whiting

Linseed Oil

Mix to the consistency of dough.

Use only enough oil to moisten all of the whitting. Putty can be pigmented to match the wood, but to a color sliightly lighter than the natural color. Putty shrinks as its dries and repeated applications are required for smooth pleasing results.

AND ANOTHER

Hide glue size(thinned with water)

Fine sawdust

Mix to the right consistency and force into cracks and holes. If putty needs thickening small amounts of cornstarch, arrowroot, fine brick powder, or fine ground clay can be added. Clay and brick dust will pigment the putty. Mix fresh for every job.

STOPPING

Stopping is of three types. The first is a thick mixture of paint base layed over primer to level the surface of interior woodwork. The second is hard & used like putty to fill holes and damage in finished furniture, it is colored to blend with the wood and finish. The third is soft stopping also called putty.

Hard stopping is made from a mixture of beeswax, shellac, resin and coloring to match the surface being repaired or leveled. It is also known as beaumontage and is usually made up in sticks of various hues and colors ahead of time. It is melted into the surface with a hot iron or flexible knife. After cooling it is leveled with a chisel, scraper or glasspaper.

Stopping is commercially available in a wide array of colors under the name "shellac sticks" and electric hot knives are sold for application. A flexible pallet knife heated over an alcohol burner works as well.