Front matter
Reading edition
A TREATISE ON THE NATURAL AND ARTIFICIAL PROCESSES EMPLOYED IN THE PREPARATION OF LUMBER FOR MANUFACTURE, WITH DETAILED EXPLANATIONS OF ITS USES, CHARACTERISTICS AND PROPERTIES
ILLUSTRATIONS
BY JOSEPH B. WAGNER AUTHOR OF "COOPERAGE"
NEW YORK D. VAN NOSTRAND COMPANY 25 PARK PLACE 1917
COPYRIGHT, 1917, BY D. VAN NOSTRAND COMPANY THE·PLIMPTON·PRESS NORWOOD·MASS·U·S·A
PREFACE
The seasoning and kiln-drying of wood is such an important process in the manufacture of woods that a need for fuller information regarding it, based upon scientific study of the behavior of various species at different mechanical temperatures, and under different drying processes is keenly felt. Everyone connected with the woodworking industry, or its use in manufactured products, is well aware of the difficulties encountered in properly seasoning or removing the moisture content without injury to the timber, and of its susceptibility to atmospheric conditions after it has been thoroughly seasoned. There is perhaps no material or substance that gives up its moisture with more resistance than wood does. It vigorously defies the efforts of human ingenuity to take away from it, without injury or destruction, that with which nature has so generously supplied it.
In the past but little has been known of this matter further than the fact that wood contained moisture which had to be removed before the wood could be made use of for commercial purposes. Within recent years, however, considerable interest has been awakened among wood-users in the operation of kiln-drying. The losses occasioned in air-drying and improper kiln-drying, and the necessity for getting the material dry as quickly as possible after it has come from the saw, in order to prepare it for manufacturing purposes, are bringing about a realization of the importance of a technical knowledge of the subject.
Since this particular subject has never before been represented by any technical work, and appears to have been neglected, it is hoped that the trade will appreciate the endeavor in bringing this book before them, as well as the difficulties encountered in compiling it, as it is the first of its kind in existence. The author trusts that his efforts will present some information that may be applied with advantage, or serve at least as a matter of consideration or investigation.
In every case the aim has been to give the facts, and wherever a machine or appliance has been illustrated or commented upon, or the name of the maker has been mentioned, it has not been with the intention either of recommending or disparaging his or their work, but has been made use of merely to illustrate the text.
The preparation of the following pages has been a work of pleasure to the author. If they prove beneficial and of service to his fellow-workmen he will have been amply repaid.
THE AUTHOR.
September, 1917
CONTENTS
Section I
TIMBERPAGES
Characteristics and Properties of Same—Structure of Wood—Properties of Wood—Classes of Trees1-7
Section II
CONIFEROUS TREES
Wood of Coniferous Trees—Bark and Pith—Sapwood and Heartwood—The Annual or Yearly Ring—Spring- and Summer-Wood—Anatomical Structure—List of Important Coniferous Trees8-30
Section III
BROAD-LEAVED TREES
Wood of Broad-leaved Trees—Minute Structure—List of Most Important Broad-leaved Trees—Red Gum—Range of Red Gum—Form of Red Gum—Tolerance of Red Gum—Its Demands upon Soil and Moisture—Reproduction of Red Gum—Second-growth Red Gum—Tupelo Gum—Uses of Tupelo Gum—Range of Tupelo Gum31-85
Section IV
GRAIN, COLOR, ODOR, WEIGHT, AND FIGURE IN WOOD
Different Grains of Wood—Color and Odor of Wood—Weight of Wood—Weight of Kiln-dried Wood of Different Species—Figure in Wood86-97
Section V
ENEMIES OF WOOD
General Remarks—Ambrosia or Timber Beetles—Round-headed Borers—Flat-headed Borers—Timber Worms—Powder Post Borers—Conditions Favorable for Insect Injury—Crude Products—Round Timber with Bark on—How to Prevent Injury—Saplings—Stave, Heading, and Shingle Bolts—Unseasoned Products in the Rough—Seasoned Products in the Rough—Dry Cooperage Stock and Wooden Truss Hoops—Staves and Heads of Barrels Containing Alcoholic Liquids98-113
Section VI
WATER IN WOOD
Distribution of Water in Wood—Seasonal Distribution of Water in Wood—Composition of Sap—Effects of Moisture on Wood—The Fibre-Saturation Point in Wood114-118
Section VII
WHAT SEASONING IS
What Seasoning Is—Difference Between Seasoned and Unseasoned Wood—Manner of Evaporation of Water—Absorption of Water by Dry Wood—Rapidity of Evaporation—Physical Properties that Influence Drying119-127
Section VIII
ADVANTAGES OF SEASONING
Advantages of Seasoning—Prevention of Checking and Splitting—Shrinkage of Wood—Expansion of Wood—Elimination of Stain and Mildew128-137
Section IX
DIFFICULTIES OF DRYING WOOD
Difficulties of Drying Wood—Changes Rendering Drying Difficult—Losses Due to Improper Kiln-drying—Properties of Wood that Effect Drying—Unsolved Problems in Kiln-drying138-144
Section X
HOW WOOD IS SEASONED
Methods of Drying—Drying at Atmospheric Pressure—Drying Under Pressure and Vacuum—Impregnation Methods—Preliminary Treatments—Out-of-door Seasoning145-155
Section XI
KILN-DRYING OF WOOD
Advantages of Kiln-drying over Air Drying—Physical Conditions Governing the Drying of Wood—Theory of Kiln-drying—Requirements in a Satisfactory Dry Kiln—Kiln-drying—Remarks—Underlying Principles—Objects of Kiln-drying—Conditions of Success—Different Treatments According to Kind—Temperature Depends—Air Circulation—Humidity—Kiln-drying—Pounds of Water Lost in Drying 100 Pounds of Green Wood in the Kiln—Kiln-drying Gum—Preliminary Steaming—Final Steaming—Kiln-drying of Green Red Gum156-184
Section XII
TYPES OF DRY KILNS
Different types of Dry Kilns—The "Blower" or "Hot Blast" Dry Kiln—Operating the "Blower" or "Hot Blast" Dry Kiln—The "Pipe" or "Moist-Air" Dry Kiln—Operating the "Pipe" or "Moist-Air" Dry Kiln—Choice of Drying Method—Kilns of Different Types—The "Progressive" Dry Kiln—The "Apartment" Dry Kiln—The "Pocket" Dry Kiln—The "Tower" Dry Kiln—The "Box" Dry Kiln185-205
Section XIII
DRY KILN SPECIALTIES
Kiln Cars and Method of Loading Same—The "Cross-wise" Piling Method—The "End-wise" Piling Method—The "Edge-wise" Piling Method—The Automatic Lumber Stacker—The Unstacker Car—Stave Piling—Shingle Piling—Stave Bolt Trucks—Different Types of Kiln Cars—Different Types of Transfer Cars—Dry Kiln Doors—Different Types of Kiln Door Carriers206-236
Section XIV
HELPFUL APPLIANCES IN KILN DRYING
The Humidity Diagram—Examples of Use—The Hygrodeik—The Recording Hygrometer—The Registering Hygrometer—The Recording Thermometer—The Registering Thermometer—The Recording Steam Gauge—The Troemroid Scalometer—Test Samples—Weighing—Examples of Use—Records of Moisture Content—Saw Mills—Factories—The Electric Heater237-250
Section XV
Bibliography—Glossary—Index of Latin Names—Index of Common Names251-257
LIST OF ILLUSTRATIONS
FIG. PAGE
1.Board of pine13
2.Wood of spruce14
3.Group of fibres from pine wood15
4.Block of oak31
5.Board of oak32
6.Cross-section of oak highly magnified32
7.Highly magnified fibres of wood33
8.Isolated fibres and cells of wood34
9.Cross-section of basswood35
10.A large red gum52
11.A tupelo gum slough53
12.Second growth red gum57
13.A cypress slough in dry season58
14.A large cottonwood78
15.Spiral grain in wood87
16.Alternating spiral grain in cypress87
17.Wavy grain in beech88
18.Section of wood showing position of the grain at base of limb89
19.Cross-section of a group of wood fibres91
20.Isolated fibres of wood91
21.Orientation of wood samples93
22.Work of ambrosia beetles in tulip or yellow poplar100
23.Work of ambrosia beetles in oak100
24.Work of round-headed and flat-headed borers in pine102
25.Work of timber worms in oak103
26.Work of powder post borers in hickory poles104
27.Work of powder post borers in hickory poles104
28.Work of powder post borers in hickory handles105
29.Work of round-headed borers in white pine staves111
30.U. S. Forest Service humidity controlled dry kiln161
31.Section through moist-air dry kiln189
32.Live steam single pipe heating apparatus190
33.Live steam double pipe heating apparatus191
34.Vertical Pipe heating apparatus193
35.Progressive dry kilns197
36.Apartment dry kilns199
37.Pocket dry kilns201
38.Tower dry kiln203
39.Box dry kiln205
40.Edge-wise method of piling206
41.Edge-wise method of piling207
42.Automatic lumber stacker208
43.Automatic lumber stacker208
44.Battery of three automatic lumber stackers209
45.Battery of three automatic lumber stackers209
46.Lumber loaded edge-wise on kiln truck210
47.The lumber unstacker211
48.The lumber unstacker car211
49.Method of piling veneer on edge212
50.Kiln truck loaded cross-wise of kiln213
51.Kiln truck loaded cross-wise of kiln214
52.Kiln truck loaded end-wise of kiln214
53.Kiln truck loaded end-wise of kiln215
54.Method of piling staves on kiln truck216
55.Method of piling staves on kiln truck216
56.Method of piling tub or pail staves on kiln truck217
57.Method of piling bundled staves on kiln truck217
58.Method of piling shingles on kiln truck218
59.Method of piling shingles on kiln truck218
60.Method of piling shingles on kiln truck219
61.Kiln truck designed for loose pail staves219
62.Kiln truck designed for handling short stock221
63.Stave bolt truck221
64.Stave bolt truck222
65.Stave bolt truck222
66.Stave bolt truck223
67.Stave bolt truck223
68.Stave bolt truck224
69.Regular 3-rail transfer car224
70.Regular 3-rail transfer car225
71.Special 4-rail transfer car225
72.Regular 2-rail transfer car225
73.Regular 2-rail transfer car 226
74.Underslung type 3-rail transfer car226
75.Underslung type 2-rail transfer car226
76.Flexible type 2-rail transfer car227
77.Regular transfer car for stave bolt trucks228
78.Regular transfer car for stave bolt trucks228
79.Special transfer car for stave bolt trucks228
80.Regular channel iron kiln truck for cross-wise piling229
81.Regular channel iron kiln truck for cross-wise piling229
82.Regular channel iron kiln truck for end-wise piling230
83.Special channel iron kiln truck for end-wise piling230
84.Regular dolly kiln truck for end-wise piling230
85.Asbestos-lined kiln door231
86.Twin door carrier with door loaded232
87.Twin door carrier for doors 18 to 35 feet wide232
88.Kiln door carrier233
89.Kiln door construction234
90.Kiln door construction235
91.Kiln door construction235
92.Kiln door construction236
93.The Humidity diagramfacing 237
94.The hygrodeik242
95.The recording hygrometer243
96.The registering hygrometer244
97.The recording thermometer245
98.The registering thermometer246
99.The recording steam gauge246
100.The troemroid scalometer247
101.The electric heater250