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                           SEASONING OF WOOD

               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"


                            [Illustration]


                               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

                                TIMBER
                                                                   PAGES

Characteristics and Properties of Same--Structure
of Wood--Properties of Wood--Classes of Trees                        1-7

                              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 Trees                       8-30

                              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 Gum                       31-85

                              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
Wood                                                               86-97

                               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 Liquids                           98-113

                              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 Wood                                   114-118

                              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 Drying                                            119-127

                             SECTION VIII

                        ADVANTAGES OF SEASONING

Advantages of Seasoning--Prevention of Checking and
Splitting--Shrinkage of Wood--Expansion of Wood--Elimination of
Stain and Mildew                                                 128-137

                              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-drying        138-144

                               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 Seasoning                                145-155

                              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 Gum           156-184

                              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 Kiln                                                   185-205

                             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 Carriers                     206-236

                              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 Heater               237-250

                              SECTION XV

Bibliography--Glossary--Index of Latin Names--Index of Common
Names                                                            251-257




                         LIST OF ILLUSTRATIONS

 FIG.                                                               PAGE

 1. Board of pine                                                     13
 2. Wood of spruce                                                    14
 3. Group of fibres from pine wood                                    15
 4. Block of oak                                                      31
 5. Board of oak                                                      32
 6. Cross-section of oak highly magnified                             32
 7. Highly magnified fibres of wood                                   33
 8. Isolated fibres and cells of wood                                 34
 9. Cross-section of basswood                                         35
10. A large red gum                                                   52
11. A tupelo gum slough                                               53
12. Second growth red gum                                             57
13. A cypress slough in dry season                                    58
14. A large cottonwood                                                78
15. Spiral grain in wood                                              87
16. Alternating spiral grain in cypress                               87
17. Wavy grain in beech                                               88
18. Section of wood showing position of the grain at base of limb     89
19. Cross-section of a group of wood fibres                           91
20. Isolated fibres of wood                                           91
21. Orientation of wood samples