120 U. S. BUREAU OF FISHERIES. 



zeno or gasoline, and is applied according to the requirements of the 

 market, which in some localities demands a heavy coating and in 

 others a much lighter finish, the latter giving a rich golden brown 

 color. Some experiments have also been made in using bright(^r col- 

 ored lacquers for this work. Several of these, made to give a bright 

 golden, copper, or other color, are extremely attractive in appearance, 

 while at tne same time protecting the tin against rust quite as well 

 as the brown. 



The industry soon outgrew the hand method of lacquering, and the 

 process which for a number of years was universal in the trade and 

 IS still used by some canneries succeeded it. For this there are a 

 number of rectangular box vats about 40 by 80 inches and 18 inches in 

 depth, the number varying with the capacity of the cannery. These 

 are usually lined with galvanized metal and provided with a grid- 

 iron-shaped iron frame, hung from a windlass or other tackle for 

 lifting or lowering from top to bottom of the vat. The cans arc 

 loaded on this gridiron, being placed in an inclined position to allow 

 the draining of the lacquer, and are lowered in the vat sufficiently to 

 submerge them in the lacciiier with which the vat is charged to a 

 depth of 7 to 10 inches. The loaded gridiron is then raisi^d to the 

 top of the vat and the cans allowed to drain and dry before piling. 

 This method, while being more effective in regard to the volume of 

 work, was still of necessity a very slow and tedious operation. In 

 damp or rainy weather, especially when it is not possible to open 

 warehouse doors and windows, the gas arising from a number of 

 these vats makes effective drying almost impossible. 



Another principal objection to this method of lacquering, which 

 applied also to all earlier attempts, was the impossibility of obtaining 

 an even coat of lacquer when the can was allowed to dry in any 

 stationary position. There was also a large waste by evaporation. 



Notwithstanding repeated efforts at invention, however, it was not 

 until 1901 that an effective machine for handling this difficult work 

 was put on the market. The f^pparatus now in use by a number of 

 canneries receives the cans on a revolving wheel fitted with rests for 

 holding them while passing through the lacquer bath. L'rom here 

 they roll upon an endless chain which revolves the cans as they pass 

 through a long box in which a hot blast dries them before they reach 

 the end of the machine. The rotating or rolling motion given to the 

 can after the lacquer bath, preventing the lacouer from draining to 

 and consequently accumulating on any part oi its surface, also has 

 the effect of distributing the lacquer evenly and results in a clean 

 and neatly finished can. The air blast facilitates the work of drying 

 to such an extent that it requires only about two minutes after being 

 deposited on the drying bed of the machine for the cans to ho ready 

 for handling, while the quantity of cans which can be handled in a 

 day is vastly greater than by the old method. 



A few fiat and oval cans are not lacquered, but are protected from 

 rust by wrapping in tissue paper, over which tlie label is placed. 



vSeveral of the largest operators have stopped lacquering the 

 sides of the cans, depending upon the label to protect this portion 

 from rust. Enameled ends are used, and, as these are bought from 

 can makers, these operators are thus enabled to get away entirely 

 from the dangers ot lacquering. 



