CHAPTER VI 

 TIGHT COOPERAGE 



GENERAL 



TIGHT cooperage refers to barrels and containers made of staves 

 and heading for liquid contents. As contrasted, therefore, with man- 

 ufacturing methods and woods used for slack cooperage barrels, a much 

 more carefully manufactured article must be produced and it must be 

 made of woods which are practically impermeable in their wood structure. 

 On account of its impermeable nature together with the fact that it does 

 not tend to discolor or lend a disagreeable odor to the contents, its hard- 

 ness, workability, excellent seasoning qualities, etc., white oak is pre- 

 eminently our best tight cooperage wood. In the early days of tight 

 cooperage manufacture, white oak constituted the only wood used. 

 This species also contributed a large portion of the raw material used for 

 slack cooperage purposes. 



Outside of the fact that white oak meets the requirements for tight 

 barrels better than any other wood, only the best quality of white oak 

 can be used. Ordinarily trees less than 18 in. in diameter at 4! ft. above 

 the ground are seldom used. In addition to this minimum size, the trees 

 must be straight-grained and sound and comparatively free from knots, 

 rot, shake, or other defects. 



Where the seasoning of contents is involved, such, for example, as 

 in the case of wines, whisky, beer and other spirituous liquors, the wood 

 composing both staves and heading must be only of an excellent grade of 

 white oak. When tight barrels are used for purposes where the season- 

 ing of the contained liquid is not involved, such, for example, as mineral 

 oils, lard, chemicals, pork, turpentine, molasses, syrup, etc., a limited 

 amount of other species such as red oak, red gum, white ash, and a few 

 other species have come into use. Owing to the curvature of the staves 

 which are largely sawed now it is very important that these be of more 

 impermeable wood than the heading. However, all woods which are 

 used as substitutes for white oak are paraffined or otherwise coated 

 on the interior to protect them against leakage. Red oak is much 



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