WASTE IN CUTTING GUM FOR COOPERAGE 



WASTE IN THE MANUFACTURE OF STAVES AND HEADING 



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Sources of Hardwood W^aste 



"Slack cooperage stock" is the term applied to the material or 

 parts used by coopers in assembling slack barrels, kegs, hogsheads, 

 tubs, kits and firkins, and includes staves, heading and hoops. In 

 general, slack cooperage stock is distinguished from that of tight 

 cooperage by the fact that the receptacles made .from it are not 

 intended for holding liquids. There is a wide range, however, 

 between the character of slack cooperage receptacles and those 

 which will hold firm, solid substances like vegetables to fine, 

 powdery substances such as flour. 



The waste resulting from the manufacture of cooperage stock 

 is generally conceded to be greater than that from the manufacture 

 of any other product. It is estimated by one investigator that as 

 much as forty-five per cent of the material for staves and hoops 

 and seventy-four per cent of that for heading is not used. Owing, 

 however, to the low grade of material which it is possible to utilize 

 in some parts of the industry, material which would in many cases 

 be a total loss unless so utilized, the matter is not as serious as 

 the figures would indicate. A considerable part of this waste 

 could be prevented, and as values increase with decreased supply 

 of material, utilization will become more nearly complete. 



The nature and extent of the waste depends upon whether it 

 occurs in the yard or in the mill. The greatest waste occurs in 

 the woods and is due to carelessness and lack of supervision. High 

 stumps and excessively long top sections are responsible for the 

 loss of from one to several stave or heading blocks on a large 

 proportion of the trees cut by some operators. Often knotty logs 

 with considerable merchantable material in them are left on the 

 ground to decay. It is best to work up timber as soon as possible 

 after it is cut, because then it is more easily worked, stands better 

 the strain of bending and looks brighter. This is an important 

 point which is often neglected, and hundreds of logs are wasted 

 because they are left too long in the woods or in the yard, and 

 thousands of staves are shaky, dull and brash, because they are 

 made from that kind of trunks. Red gum logs in particular are 

 very liable to sap stain if cut in summer and left in damp situa- 

 tions for a time. This is not due to any greater sap content but 

 to the more favorable conditions for the development of fungi. 



A loss which amounts to a great deal in the aggregate is due to 

 improper cutting lengths of the logs. As summed up by the 

 National Conservation Commission: "Logs intended for staves 

 are cut in the woods to lengths which are multiples of thirty-two 

 inches, because of poor judgment of the workman or wood super- 

 intendent, and it is often found necessary to utilize at the mill 

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for heading material which was cut in the woods for staves. In 

 logs which were cut for six-stave lengths the waste, if it is found 

 necessary to utilize this for heading, is three inches to the log. 

 If, on the other hand, the log were cut for five-stave lengths, the 

 waste, if it is found necessary to use this for heading, is thirteen 

 inches. Not infrequently, through carelessness of workmen, log» 

 are cut too short in the woods and the last block must be thrown 

 out at the mill." 



A large ma.iority of the manufacturers of slack cooperage stock 

 specialize in making only one of the parts of which a barrel or 

 other receptacle is composed. Thus one establishment will make 

 staves, another heading and another hoops. A few concerns make 

 two of these parts, but rarely are all three produced by the same 

 concern. One reason for this condition is that the different parts- 

 require different kinds of wood and usually all three kinds are not 

 available to one plant. This is unfortunate, for it is to this spe- 

 cializing that much waste is due. For instance, logs that will not 

 make good hoops will frequently make good staves and logs or 

 portions of them which are not suitable for staves will often make 

 very good heading. Where the industries cannot be combined it 

 would appear good business to include other manufactures to utilize 

 the odds and ends left over. When timber is cheap, however, the 

 increased cost of articles made from scraps will usually more than 

 offset the saving in the cost of material, making such side lines 

 impracticable. 



It is the usual practice in making slack staves and heading to 

 cut the log into blocks in the mill- and then saw them into bolts. 

 In some mills, however, the whole log is first sawed into quarters 

 or sixths and these long bolts are then cut into stave or heading 

 lengths by a small cut-off saw. This is inadvisable, since each block 

 should be handled separately if bolts are to be secured from which 

 prime staves can be cut. The metlwd of first quartering the whole 

 log before cutting into blocks does not take into account variations 

 in the grain and provides no way for tipping and turning the log 

 to get the bolts into the best form. 



The bigger the log the greater the percentage of No. 1 staves 

 that can be obtained from it, and since it costs as much to manu- 

 facture No. 2 staves as it does the best quality, small logs are 

 not in great demand. If too small to quarter they will produce 

 too many "washboards." This fact tends to increase the waste 

 in the woods unless the stave mill also makes heading, because 

 considerably smaller logs can be used for heading than are prac- 

 ticable for staves. Since nearly all slack cooperage staves are 



