Early Methods of Grinding Paint

Excerpted from The Chronicle, Vol. XVIII, No. 3, Sept. 1965 by Alexander Farnham

For our early ancestors, the stone and muller, fig. I, and mortar and pestle were about the only means at hand to grind paint for preserving their houses and barns and decorating their homes. John Smith, C. M., in his book, "The Art of Painting in Oil," published in 1788, describes the ancient method of grinding paint with stone and muller as follows:

"When you come to grind colours, let your grinding ­stone be placed about the height of your middle; let it stand firm and fast, so that it joggle not up and down; then take a small quantity of the colour you intend to grind ( two spoonsful is enough) for the less you grind at a time the easier and finer will your colour be ground; lay these two spoonsfuls of colour on the midst of your stone, and put a little of your linseed oil to it (but be sure you put not too much at first) then with your mul­ler mix it together a little, and turn your muller three or four times about, and if you find there be not oil enough, put a little more to it, and grind it till it come to the consistence of an ointment, or appears as free from sandiness, or any sort of lumps, as the most curious sort of butter; for then it grinds much better and sooner than when it is so thin as to run about the stone: You must oftentimes, in the grinding, bring your colour together with a piece of lantern-horn, and with the same keep it together in the middle of your stone; when you find you have ground it fine enough by the continual motion of your muller about the stone, holding it down as hard as your strength will permit (which you must also move with such a sleight, as to gather the colour under it) and that no knots, nor grittiness, remain, but it is as fine even as butter, or as oil itself; then with your horn cleanse it off the stones into a gally-pot, pan, or whatever else you design to put it into, and then lay more colour on your stone, and proceed to grinding as before: Do so often till you have ground as much of this colour as shall serve your occasions; and if you grind other colours after it, let the stone be well cleansed from the first colour, with a cloth and fine dry ashes, or sand.

Some grind at one time, so much of even, colour, as may be sufficient to serve a long time together, which they keep tied up close in ox or sheep's bladders; and by this method a man prevents the daubing of himself too often, by grinding of colours."

Largely the pigments ground by the first European settlers of this country were limited to those that they could dig up near their homes. These earth colours they would wash and when dry would grind in either linseed, nut, or if near the coast, fish oil. To be sure the paint was free from grit after grinding, it was tested by smearing a sample of it on a sheet of glass which was then help up to the light. Any coarseness would show up and further grinding would be necessary.

As demand for paint grew greater, man's inventive­ness was put to work on developing a means of produc­ing more with less effort, and thus the first paint mill came into existence. The paint mill, fig. 2, which I have drawn for this article was patented in 1840, and has the name Adams cast on the crank handle. All indications would point to its having been clamped to a shelf or work bench. There is an inch and a quarter long by quarter inch wide slot in the back of the plate that supports the hopper. On either side of this slot, facing downward, there is a one-sixth inch long knob. It seems reasonable to assume that the mill was held down by means of a wing-nutted bolt through the slot, and that the two knobs fitted into holes thus preventing the mill from shifting from side to side. The mechanism of the mill is ex­tremely simple. The crank handle is attached to a rod protruding from a spherical casting which turns within the hopper. There are twelve grooves cast in the sphere and when the crank is turned counter clockwise, pigment is caught between these grooves and the scalloped edge of the hopper. The pigment had to be put through sev­eral times to secure the desired fitness.

In the mid-1800s a painter by the name of A. H. Brainard invented what he called his Improved Paint Mill, fig. 3. Two examples of this mill are illustrated with cuts from an 1855 advertisement. Four models were available. No. 1, a medium sized hand mill, in­tended for coach painters, or others who used color rather thin, sold for $11. No. 2 was twice as large and cost $13. No. 3 was five times the size of No. 1 and was intended to run exclus1vely by power. No. 4 was even larger and not only ground the colors, but also had a mixer. It sold for $85. The advantages of the Brain­ard mill over all others, according to the sellers, were that no color however coarse needs grinding through the mill but once to render it fine enough for any purpose; it does not throw when run rapidly, as in the case with all horizontal mills; and coarse and heavy colors do not settle in it as they do in all other upright mills.

In 1855, Crocker & Co., at the sign of the medicine chest and mortar, Boston, Mass., sold Brainard's mill as well as paints and oils. Eleven years later in Bald­win's consolidated business directory, there is mention of only two sources of paint mills, one of which was Holmes & Blanchard of Boston who advertised themselves as manufactures and sole proprietors of Brainard's Improv­ed Iron Paint Mills.

With the passing of years and the growth of paint manufacturers, fewer paint mills were in use by paint shops and house painters until today it would be hard to find one that would wish to go to the effort of grinding his own pigments.