Chapter XIV: Section X: Picking Band Butts

It is the paradox of vegetable tannage that the less the pelt is tanned the stronger is the leather produced. The manufacture of butts for picking bands affords a good illustration. What is required is a leather of maximum toughness, pliability and durability. Any factor reducing the tensile strength of the leather is fatal. Hence, compared with most other tannages, picking band butts are under-tanned. To ensure the desired softness and pliability, moreover, it is necessary to have a mellow liming, rather heavy bating, and a soft mellow tannage in sweet and weak liquors. The required durability and the necessity for weak liquors both point to oak bark as the most suitable tanning material, assisted by some gambier in the early stages.

A good quality hide is chosen, and given a long and mellow liming of about 15-16 days. The one-pit system may be used, and the hides are put into an old lime for about five days with frequent handling and then placed in a new lime which is made up in a pit containing about a foot depth of the old liquor. After about twelve days another 1/3 cwt. of lime may be added.

After unhairing and fleshing the goods are bated in pigeon dung for four days at a temperature of about 78° F., handling twice on the first and last days. The bating is stopped and the deliming completed by paddling with boric acid (15 lbs. per 100 butts).

The tannage is commenced by paddling in a spent handler liquor (4°) to which a little gambier has been added. The butts then go through the first handlers (5°-15°), which are rounds of ten pits in which the goods are handled every day in the first week, and alternate days in the second week, and are shifted forward twice a week in the next pit. The goods are therefore in this set for five weeks. Gambier is added to these liquors as needed. The butts next pass to duster rounds of four pits, in which they are dusted down in a liquor of 20° for four weeks with 1-2 cwt. of oak bark. The liquor is obtained from the leaches, and afterwards run alternately to the leaches and to the first handlers. As many as six layers are now given of 20°-25° strength, in which the butts are dusted down with 2-3 cwt. oak bark for three weeks. The layer liquors are received from and returned to the leaches, which are made from the "fishings" from the layers. The tannage lasts, therefore, 27 weeks, of which 18 weeks (two-thirds) are in layers.

Shorter tannages are now often given, using stronger liquors, much as in ordinary dressing leather.

The tanned butts are rough dried, and then wet in for shaving. They are thoroughly scoured, flesh and grain. They are next drummed for three-quarters of an hour in sumach, struck out and hung up to samm. Hand stuffing is best, to avoid any tendering owing to high temperature, but drum stuffing is also used. After setting out and stoning on the grain they are stuffed with warm cod oil and laid away in grease for several weeks, re-oiling occasionally. They may be stained before stuffing.

REFERENCE.

Bennett, "Manufacture of Leather," pp. 203, 310.