$5.

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WOODS to
WOODSHOP
A Guide for Producing the Best Lumber

By Gene Wengert

Presented by Wood-Mizer

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 WOODS to
WOODSHOP
A Guide for Producing the Best Lumber

PART 1 Sawing the Best Lumber

LOG QUALITY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
SAWMILLING QUALITY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
HARDWOOD SAWING TECHNIQUES
Hardwood Lumber Grades and Prices . . . . . . . . . . . . . . . . . . . 7-8
Hardwood Sawing Patterns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Opening Face . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Specific Sawing Suggestions
General Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Log Rotation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Opening Face Sizes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Sweepy Logs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Quartersawing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
SOFTWOOD SAWING TECHNIQUE
Sawing Softwood Logs Into Construction Lumber . . . . . . . . . . 14
Sawing Softwood Logs into Boards and Lumber for
Remanufacturing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

PART 2 Drying the Best Lumber

WHY DRY LUMBER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
MEASURING MOISTURE CONTENT . . . . . . . . . . . . . . . . . . . . 17
WATER IN THE WOOD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
AS SOON AS THE LUMBER IS SAWN...
Drying Risks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Sorting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Stacking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
LUMBER DRYING
Initial Drying . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Air-Drying . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Kiln-Drying . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

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 HOW DRY IS DRY ENOUGH?
Achieving Proper Final Moisture Content . . . . . . . . . . . . . . . . . 20
ADDITIONAL QUALITY CHARACTERISTICS
OF THE DRYING PROCESS
Freedom from Checks and Splits . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Freedom from Warp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Freedom from Casehardening (Drying Stresses) . . . . . . . . . . . . . 21

TABLE OF CONTENTS
Good Color . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
High Strength . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Good Machinability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Good Gluability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
MEASURING MC
Oven-drying . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Electric Meters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

PART 3 Additional Resources

SAWING AND GRADING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
DRYING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Wood is a valuable material. Although wood is plentiful in the U.S., with annual
growth of hardwoods exceeding harvest by 25% for the past 75 years, we need to
assure that we will not waste this valuable natural resource as we convert it into lum-
ber, and as we convert the lumber into furniture, cabinets, buildings, and other useful
products.

A nice size tree has just been felled in the woods. Your plans are to saw as much
of the tree as possible into high quality lumber. You want to do this with a minimal
amount of waste and, at the same time, you want to maximize the value and useful-
ness of the lumber you produce. How do you proceed?

This text was written to provide both the hobbyist and the professional with basic,
practical information on how to saw and dry lumber efficiently with minimal loss and Gene Wengert
downfall. The best operating procedures begin in the woods just after the tree is
is Professor and
felled. In Part 1 of this booklet, practical, efficient sawmilling procedures that are dis-
cussed and illustrated. Suggested drying procedures are then presented. As a con- Extension Specialist
clusion to this text, the final section lists sources of additional information on sawing Emeritus, Department
and drying. of Forest Ecology and

All the information presented is based on decades of experience. Therefore, unless Management, University
there is a good reason not to follow the suggestions presented here, these guidelines of Wisconsin-Madison,
will be the most profitable and will waste as little of our resource as possible. and President of The

We hope that you find all the information you need to convert our valuable, renewable Wood Doctor’s Rx, LLC.
resource into useful and durable wood products that will last for centuries.

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 Sawing the Best Lumber
1
PART 1

LOG QUALITY
It is difficult to produce high-quality lumber from logs that are knotty and crooked. Effective sawing decisions
require knowledge of the logs’ quality. So, the first step before sawmilling begins is always to evaluate or grade
the logs to estimate their quality. Logs are graded based on their faces. A log has four faces, each face repre-
senting 1/4 of the circumference and being the full length of the log (Figure 1). The four faces do not overlap
each other. A clear face is free of knots, knot scars on the bark, seams, splits, rot, insect damage, and so on.

SAWING THE BEST LUMBER

The clearer the face, the higher the value and the better the lumber that will be produced from the log. Detailed
instructions for log grading are available from many state forestry offices, or request Forest Facts #74 (send
$2 and a SASE) to the Forestry Department of the University of Wisconsin, 1630 Linden Drive, Madison,
WI 53706.

Log value is based on the amount and value of lum- quality. Logs stored for more than several weeks
ber that will be produced. Based on the results from in warm weather may have already begun to stain,
sawing thousands of hardwood logs, the volume of especially at the log ends and wherever the bark
lumber produced, total and by grade, and the value has scuffed off. Therefore, prompt sawing of logs in
of the lumber produced from any size and grade log warm weather is essential.
can be estimated. Several examples for red oak logs
are given below (Table 1). Exposed log ends also are likely to begin drying
immediately, resulting in development of stain, end
Logs that are crooked or short will produce much cracks, splits, and checks. It is quite easy for the
less high-value lumber than long, straight logs. stain and cracks to penetrate over six inches in just a
Further, logs eight feet and shorter will seldom pro- few months. Further, the dry ends are difficult to saw
duce much high-quality lumber. Therefore, when accurately. The saw wanders excessively in this dry
bucking a tree into logs, always try to maximize log wood, giving erratic lumber thicknesses. Therefore,
length, but at the same time, minimize crookedness. all logs should be end-coated promptly with a vapor
These log length bucking decisions are critical for resistant coating (commercial wax coatings, such as
large diameter logs. On the other hand, logs under Anchor Seal, are very popular) to prevent end checks
16 inches in diameter (small end, inside bark) will and reduce the risk of end stain.
seldom produce much high-quality lumber, so length
decisions for these smaller logs are not very critical. In addition to the damage that can be seen, such as
Incidentally, it is typical that the length of logs is usu- end stain and end cracks, stored logs have certain
ally about 2 inches over the last full foot; that is, an undesirable chemical changes occurring within the
8-foot log is really 8' 2", an 11-foot log is 11' 2", and wood. Lumber from logs stored several months dur-
so on. ing warm weather is at least 10 times more likely
to develop cracks and checks in drying. Lumber
Once the logs have been manufactured, they need to from stored logs is perhaps 20 times more likely to
be handled correctly and sawn promptly. Appreciate develop objectionable drying stains, including sticker
that the way the logs are handled influences lumber stain.

Table 1 Lumber volume and value from various sized red oak logs

Log Log Log LUMBER PRODUCED Lumber

Diameter Length Grade Selects & Btr No.1C No.2C No.3C Value
(inch) (feet) (Bd Ft) (Bd Ft) (Bd Ft) (Bd Ft) ($)
12 10 3 2 11 20 25 32
12 12 2 12 20 23 17 51
14 10 3 4 18 27 30 47
14 12 2 20 33 28 20 76
15 12 2 25 40 31 20 90
16 16 1 90 45 34 13 173
16 16 2 40 64 44 29 140
16 16 3 12 44 53 56 103
20 12 1 124 54 31 18 223
24 12 1 197 81 33 22 338
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 Knot

FIGURE 1 Seam

to 1/16-inch more (per inch of thickness) than

flatsawn lumber during drying, meaning that the
ce
3 green size may have to be increased, further
Fa
reducing yield.

ce
2 • Thick lumber requires substantially longer drying
Fa
time and milder drying conditions. For example:
8/4 requires 2.5 times longer for drying than 4/4
1
Fa
ce lumber. Therefore, in most cases, saw lumber no
thicker than required. Do not saw thick lumber
Face 4
that will be resawn into thinner pieces after dry-
ing. If thicker pieces are required, consider saw-
ing thinner pieces to glue together later. After
sawing, keep them in order, so that after drying
you can glue them back together in the same
order that they came from the log. In this way,
SAWMILLING QUALITY the grain of the small pieces matches very well;
Sawing procedures will influence lumber quality. it will be difficult to see that the large, thick piece
The following criteria are the technical basis used to is actually made of several glued-up pieces of
develop the suggested sawing procedures discussed wood!
in the next section:
• Lumber that has the rings off center (when look-
• The clearest, knot-free, strongest, most valuable ing at the end grain of the lumber) will bend to
lumber is on the outside of a log. Quality goes the side more often than not. Therefore, always
down as the lumber is sawn closer to the center try to keep the rings centered so that the two
(called the pith) of the log. edges of the lumber are mirror images.

• Wide, long, clear pieces of lumber are the most • Lumber including the pith will warp badly at
valuable. The best hardwood lumber grade times and will almost always develop a large
guarantees that the lumber is at least 83% clear. split.
Attending a three-day hardwood lumber grad- • Lumber from crooked logs has high slope of
ing class is well worth the time and expense. grain (SOG). High SOG also results when the
Contact the National Hardwood Lumber lumber is not sawn parallel to the bark. Lumber
Association for the dates of a class in your area: with such grain pattern will often warp badly
(901) 377-1818. Hardwood lumber graders do during drying. Lumber with a high SOG has
not need to be certified or licensed. greatly reduced strength as well. Often, the
• Softwood lumber grading is much more complex strength is critical when sawing softwood con-
than hardwood lumber grading, and due to struction lumber, so SOG is an important factor
safety concerns, must be done by a certified, to consider when evaluating and sawing logs.
licensed grader. Most wood framed buildings Lumber with high SOG also machines poorly,
are required by the building codes to be built with grain tear-out and raised grain common.
with graded, certified lumber. Check with local • Softwood lumber intended for construction
building officials for specific requirements and purposes, with large knots near the edge is not
rules in your area. as strong as if the knots were in the center face.
• Quartersawn lumber (with the rings going from Knots on the edges running toward the center of
face to face, rather than edge to edge) requires the piece, called spike knots, make the piece of
up to 30% longer drying time. Quartersawn lumber especially weak. Lumber with large knots
lumber has a different grain pattern than flat- is weaker than lumber with smaller knots.
sawn, especially in oak, ash, sycamore, beech, • Lumber intended for remanufacturing, especially
and hackberry. This grain may be unwanted lumber that will be cut up into smaller pieces for
by some customers. When sawing quarter- furniture, cabinets, and so on, is most valuable if
sawn lumber, yields of lumber from the log are the knots are near an edge or end, maximizing
reduced, compared to more typical sawing pat- the size (length and width) of the clear, knot-free
terns. Quartersawn lumber may also shrink up areas in the lumber.
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HARDWOOD SAWING TECHNIQUES
The initial sawing operation is THE KEY to obtaining the highest dollar return and the most useful lumber
from every log processed. The operator of the saw, the “sawyer,” must recognize the potential product grade
mix that will maximize the value of the log, and then manipulate the log to achieve this maximum value. This
requires a “sixth sense” with x-ray vision to visualize what is inside the log before it is sawn.

In order to do an effective job, the sawyer must receive logs that have been properly felled and handled. Logs
1
should not have large protuberances, pronounced crook, kink, or sweep, or jagged ends. Log ends should
not be dried out. In short, the sawyer is no magician—the way that logs are harvested, bucked to length, and

SAWING THE BEST LUMBER

stored before sawing affects their potential value when sawn into lumber.

To optimize log and product value, the sawyer must also consider how the lumber will be edged and trimmed.
If the edging and trimming are not done by the sawyer, then the edgerman, trimmerman and sawyer must
develop good communication along with a high degree of skill and judgment. They must act together as a
team. They also must operate their equipment safely and efficiently. As a minimum, these people must have a
thorough understanding of lumber grades and current lumber values.

Hardwood Lumber Grades and Prices

There are five basic grades of hardwood lumber than with FAS. Common lumber can be as short as
(Figure 2)—FAS, Selects (sometimes sold as FAS 4’ and as narrow as 3”.
1-Face), No.1 Common, No.2 Common, and No.3
Common. Here is a brief summary of the grades: Selects and FAS 1-Face are No.1 Common pieces
that have the better face equivalent to FAS.
FAS is a piece of lumber that is at least 83% clear No.2 Common is 50% clear on the worst side and
on the worst side of the piece. (Clear means free stain is a defect, but with No.2B Common, stain is
from rot, pith, shake, wane, knots, stain, and other not a defect and is ignored.
defects.) The clear area or areas are wide and long;
the lumber itself must be at least 6” x 8’. No.3A Common is 33% clear on the worst side. The
lowest grade, No.3B Common, requires only 25% of
No.1 Common is at least 67% clear on the worst the piece to be sound, not clear.
side of the lumber. The clear areas can be smaller

FIGURE 2
wane
FAS
knots
$9.50

No.1C
$6.50

No. 2AC
$3.00

No. 3AC
split
$2.25

No. 3BC
worm holes
$1.75 stain

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 There are many special cases and situa-
tions when grading lumber; this is just a
general summary. The NHLA publishes an Table 2 Typical Prices of Kiln-Dried,
illustrated Inspection School Manual (refer- 4/4 Hardwood Lumber (12/05)
enced in Part 3 of this report) to help learn
Species FAS No. 1C No. 2C
the grading rules.
- - - - - - $ / MBF - - - - - -
Lumber prices on the retail market vary tre- Ash 1110 780 570
mendously, even within an individual state.
Birch, yellow 1800 1215 805
Upper grades of kiln-dried No.1 Common
and Better will sell quickly and at very prof- Cherry 3000 1745 1000
itable prices. The wholesale market prices Cottonwood 755 500 250
for lumber vary month to month. Several Maple, hard 2510 1820 1110
publications tabulate and publish current
Maple, soft 1725 1000 550
prices, including the Hardwood Market
Report (Memphis, TN) and the Weekly Oak, red 1525 875 645
Hardwood Review (Charlotte, NC). Some Oak, white 1550 820 570
typical 2005 prices for kiln-dried lumber Walnut 2520 1405 1165
(wholesale, FOB mill, gross tally) are given Yellow poplar 885 560 400
in Table 2. State forestry officials may also
publish a newsletter that has ads for lum-
ber.
Below, especially if sold green. Yet, some lower-grade
Usually, the green lumber or air-dried lumber prices logs may produce 50% of this low-grade lumber.
are lower by $250 or more per MBF. Note that the The most profitable option for lower-grade lumber is
prices quoted are based on measurement of footage to kiln-dry the lumber and then cut the lumber into
and grade after drying. smaller, clear (or nearly clear) pieces before selling.
Although small pieces cannot be graded with stan-
For most species, there are poor markets and poor dard rules, such pieces are very attractive for hobbyist
profits for lower grades of lumber, No.2 Common and and small businesses. Typically, these pieces would

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Hardwood Sawing Patterns

1
The actual sawing pattern used (sawing pattern includes lumber thickness, log rotation, and taper offset)
depends on many factors, including species, log quality, log size, mill design, sawing equipment, and lumber
grade values. There are three basic sawing options for standard lumber; however, for quartersawn lumber, see
Figure 5 and the accompanying discussion.

1 - Grade Sawing (or Around Sawing) FIGURE 3 Face 3

The log is sawn and turned to a new face, sawn and

SAWING THE BEST LUMBER

turned again, perhaps turned as many as five times
(Figure 3). This is the best (financially) for medium-
and high-quality logs, even though it may be difficult
to turn a log on some mills and daily production vol-
ume may be lower. Hydraulic log turning is much bet- Face 2 Face 1
ter than “arm-strong” power!

Face 4

2 - Live Sawing FIGURE 4

(or Through-and-Through Sawing)
The log is sawn about halfway through on the opening
face and then turned once to the opposite face and
sawn on that face until finished (Figure 4). Although
this can be the easiest and quickest sawing method,
live sawing means that every piece of lumber must be Face 2 Face 3

edged—for highest value, many pieces will be ripped

into two or three pieces as well. Further, live-sawn
lumber is quite wide and heavy, is lower in grade, and
has a lot of quartersawn grain. Live-sawn lumber often
has excessive warp in the drying process. In short,
live-sawing is usually best only for lower quality logs
where the above disadvantages are not important.

3 - Cant Sawing FIGURE 5 Face 3

The log is sawn much like grade sawing, but the

center of the log, which may be a piece with
dimensions of 7” x 9”, 10” x 10”, or so, is either sent
to another machine for further processing or is sold as
a large (and heavy) timber (Figure 5). Cant sawing
maximizes sawmill production (board feet per day)
Face 3 Face 3
and is commonly used throughout the hardwood CANT

industry in medium and large size mills. It is used

primarily on medium- and low-quality logs where the
lumber from the center of the log will not be very
high in value. With cant sawing, valuable time and
effort is not wasted manufacturing low-grade,
low-value lumber.
Face 3
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 Opening Face
Of all the decisions facing the sawyer, the decision as to which face to open first (that is, where to begin
sawing) is the most important. (A log is divided into four faces, each face being of the log’s circumference, full
length, and not overlapping another face. Once the slab is removed from a face, the flat surface is the face.)
The choice of the opening face determines the location of all the other faces. Initially, a log could be sawn in
several million different ways; only a hundred of these ways are most profitable! Once the opening face is cho-
sen, there are now only several thousand decisions for the sawyer to make.

In grade or cant sawing methods, there are two basic opening face options—

Option #1: The poorest face of the four faces is opened first without any taper set. (Taper set refers to
the process of raising or skewing the log so that the saw cuts parallel to the bark on the face being sawn.)
Because this is the poorest face, this means that short lumber and potentially large slabs will come from the
very low-value part of the log. With no taper setting, it means that the opposite face, which is a better face, will
be sawn parallel to the bark when the log is turned without having to use taper sets on that face. As a result,
higher-grade lumber which comes from this better face will be full length.

Option #2: The best face on the log is opened first with full taper. Full taper means that the log is raised or
skewed as much as needed so that the first cut runs parallel to the bark. This means, as in Option #1, that the
higher grade face will be sawn parallel to the bark and will produce full-length lumber.

The end results of either method will be nearly the same, but there is one advantage to Option #2. It is
easier to position the log (i.e., rotate it slightly) so that the opening face is as clear (free of defects) as possible.
With Option #1, the back side (or opposite side) of the log is the better face, but fine-tuning the rotation is diffi-
cult as the back side cannot be seen easily in a production situation. When sawing a high-grade log with many
clear areas and faces, the difference between Option #1 and #2 is small. However, in a lower-grade log with
limited clearness, Option #2 will often prove to be better.

3
ce
Fa

2
ce
Fa

1
ce
Fa

Face 4

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 1
Specific Sawing Suggestions
(NOTE: All suggestion here must factor in safety requirements first!)

General Recommendations To begin, the sawyer (using Option #1) selects the
HIGH-QUALITY BUTT LOGS (a butt log is the
worst face and opens it without taper. Do not saw
bottom log of the tree) will yield the most valuable
the opening, low-grade face very long before rota-
lumber. Therefore, when sawing such logs, the saw-
tion. With a small log, the worst face could have just
yer must determine which mix of thicknesses will
a slab removed (that is, just one cut full-length), or
maximize the volume and value recovery for each
a slab and a short board before the log is rotated to

SAWING THE BEST LUMBER

log face. As the price of lumber increases with thick-
the opposite face. With a larger log, several short
ness—for example, 4/4, FAS, green hard maple
pieces of lumber could be removed, and at times
sells at $1060 per MBF wholesale, while 8/4 sells at
even a full-length piece could be sawn.
$1210—and because thicker lumber has less saw-
dust and higher lumber yields per log (as
much as 10% more lumber for a log sawn
into 8/4 versus 4/4), this decision can have
a large impact on profits. However, if, when
producing thicker lumber, the grade of the
lumber drops to No. 2 Common or lower,
even though the better side is clear or nearly
clear, there would be substantial loss, as
the market for thick, low-grade lumber is
poor. The sawyer must try to switch to 4/4
or 5/4 thickness before the grade drops.
(Remember—you do not make any money
sawing lumber until the lumber is sold. For
this reason, the grades, value, and useful-
ness of the lumber produced is critical for
profitable operations.)

From these high-quality logs, production of

large timber and railway ties from the center
would often be ill-advised, as these large cants will
Alternately, the sawyer (using Option #2) selects the
often have substantial middle- and high-grade lum-
best face and opens it with full taper. This face is
ber. In other words, cant value would be less than
then sawn heavily before the log is rotated to another
lumber value.
face.
For these high-grade logs, grade sawing is recom-
POOR QUALITY, SOUND LOGS which will produce
mended. In fact, taper-sawing (skewing the log on
no higher than No. 2 Common lumber should be
the carriage so that lumber is sawn parallel to the
sawn as quickly as possible. In other words, there
bark) is recommended for all “good” faces. This will
is little or no profit in these logs, so they should be
result in putting clear wood into full-length, more
removed from the sawmill as quickly as possible.
valuable pieces of lumber and will avoid cutting clear
Any sawing method is acceptable, so long as the
wood into short pieces. When the lower-grade por-
log can be sawn quickly and safely. Most often the
tion of the log is reached, then any taper would be
log would be cant-sawn (often financially the best)
taken out of the log; that is, a wedge-shaped piece
or live-sawn. Every minute of sawing time carries a
would be cut to square the remaining cant and mini-
price ticket, so it is important to achieve the compro-
mize edging of the
mise between sawing cost (perhaps $100 per MBF)
remaining pieces.
and lumber value. Log-turning should be kept to an
absolute minimum for low-value logs.
MEDIUM-QUALITY LOGS offer considerable
challenge to the sawyer because they contain large
UNSOUND LOGS should never be purchased in the
volumes of No. 1 Common and Better lumber. It
first place as profit is nonexistent and safety risk can
takes skill to recover this valuable lumber. Grade
be high. It is a better investment to spend money for
sawing, which means rotating the log from one face
higher-quality logs which have good profit potential
to the next, will provide the highest value; these rota-
than to purchase low-grade, unsound, non-profit
tion decisions are critical decisions.
logs.

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 Log Rotation of lumber that will be sawn is high grade (Select, FAS
Lumber is sawn off of one face until the sawyer 1-Face, or FAS), then the minimum width of the open-
expects that the next piece of lumber to be sawn ing face (that is, the minimum width of wood measured
will be lower in grade than if lumber were sawn off of on the log) should be 6-1/2 inches. This width is con-
the adjacent faces. (Exception: A “worst face” must sidered along the entire length of the log. (Why do we
be sawn deep enough to achieve a satisfactory flat use 6-1/2 inch opening size? Because FAS 1-Face and
surface before turning the log to another face.) When FAS lumber must be at least 6 inches wide. To allow
the grade estimate for the present face is lower than for shrinkage and perhaps a little light edging at times,
either of the adjacent faces, the log is rotated to a plus because a little extra width can help the lumber
new face. (In other words, a good face is sawn deep- achieve the desired grade, 6-1/2-inch width is recom-
ly; a poor face may only be slabbed or have a slab mended rather than 6.0 inches. Although Selects can
and one board removed.) This rule for rotation applies be 4- or 5-inches wide, the wane restrictions on these
to all faces and throughout the sawing process. pieces are so severe that they are not worth manufac-
turing intentionally.)
It is preferred that the log is rotated 180 degrees
from the opening face to the second face. As many Lower Grade Face
mills do not use this rotation pattern, even though it If the sawyer believes that the best grade of lumber
has been standard since 1956, it is necessary to dis- that can be produced is No. 1 Common or lower, then
cuss the advantages in more detail. the minimum opening face width should be 4-1/2
inches. This opening width is only considered along
Consider a 24-inch log (it works for any size log, a 4-foot length of the log, assuming that the short-
however). The 180-degree rotation results in 8 pieces est piece of lumber that can be sold is four feet long.
needing edging, while the poor method (always (Adjust this length for the shortest piece that is sold at
rotating to an adjacent face) results in 13 pieces that your mill.)
need to be edged. This alone is quite significant
in terms of work load for a small sawmiller. The
180- degree rotation method produces more wide Table 3 The size of pieces of lumber sawn with
pieces, which are usually more valuable (Table 180 degree rotation and with adjacent from a
3). In addition, there are 8 pieces in the adjacent 24-inch diameter log.
method that have rings that are not centered,
Width of Lumber Number of Pieces
edge to edge, which means that these pieces are
180 Degree Adjacent
likely to develop side-bend in drying. Further, if
20" 2 1
this is a species like walnut or red oak with a nar-
row band of sapwood, in the 180-degree method, 17" 2 1
10 pieces will have sapwood in them; in the adja- 15" 0 1
cent method, 13 pieces. Sapwood causes drying 14" 2 3
problems (checks easier for oak) and also color 13" 0 2
problems for some customers. The effect of log 11" 10 8
stress or “spring” is minimized with 180 rotation, 10" 2 1
as well.

We are aware that rotating to an adjacent face may

be easier, but the economic and safety benefits Sweepy Logs
strongly encourage 180-degree rotation. After the Better quality logs with pronounced sweep should
first two opposite faces are sawn, the third and be sawn initially with the “belly” to the saw or with
fourth face are sawn. When beginning on the third the “ears” to the saw, rather than by looking for clear
and fourth faces (which are opposite each other), the faces. The ears are typically removed in one or two
poorer face of the two is opened first with no taper, passes, providing a flat surface along the entire log
if this third face is not very high quality. However, a length. The belly can be sawn in several passes, often
high-quality face should probably always be opened producing some short, clear pieces of lumber. Once
parallel to the bark, which means that taper-setting is the log is squared, then the remaining two faces are
required. sawn, most often turning the log only once, but using
standard log turning rules and procedures mentioned
Opening Face Sizes previously. (Hint: When edging lumber from the belly,
The width of the opening face, or width of the slab- long and narrow is better than fat and short.)
bing cut, on all of the four faces is critical.
Poor-quality logs with pronounced sweep should never
Good Grade Face reach the sawmill if the purpose of the lumber is for
If the sawyer believes that the grade of the first piece profit.
12
12
 1
Quartersawing
Quartersawn lumber offers several advantages compared to flatsawn lumber. Quartersawn lumber typically has
heavy ray fleck, which some people find appealing. Quartersawn has about half of the shrinkage in width as
flatsawn (3% instead of 6% when drying). Quartersawn lumber dries flatter and has less risk of checking dur-
ing drying. Quartersawn lumber is more stable in an environment with varying humidity. Quartersawn lumber
wears more evenly when used as flooring.

On the other hand, producing quartersawn lumber often results in 20% lower yields from the log. Lumber
production rates are much lower as well. Quartersawn lumber requires 15% or so longer drying times.
Quartersawn lumber shrinks twice as much in thickness as flatsawn. Quartersawn lumber will have spike

SAWING THE BEST LUMBER

knots, compared to the circular knots in flatsawn lumber; spike knots greatly reduce the strength of lumber.

Sawing procedures are illustrated in Figure 6 for large logs and Figure 7 for smaller logs. As always, sawing
must be done with safety in mind.

FIGURE 6
gth
Len
F ull
a nd
L og
1 /2" ood
6 a G
for

Opening Face

FIGURE 7
g
4' Lo
ty
ali
Qu
" w er g
/2 o n
4 1 r a L ' Lo
fo nd 4
a

Opening Face

13
13
 SOFTWOOD SAWING TECHNIQUES
Many of the techniques used for hardwood log sawing apply to softwoods as well. A few differences are
highlighted in the following two sections.

Sawing Softwood Logs Into Construction Lumber

The following outline indicates the best way (most economical way) to saw softwood logs most of the time.
Certainly, safety concerns must override volume or value concerns.

Step 1. Position the log so that the smaller defects A butt log will have less defect in the center and so
will show up in the center of the lumber, where such should probably not be converted into a large timber,
defects are less serious with respect to strength. but should be sawn entirely into lumber.
When possible, consider putting all the knots or
other defects into one face leaving the other faces Step 4. Always turn the log from the present face to
clear. However, for construction lumber, usually a another face if the grade of lumber on the adjacent
clear piece is no more valuable than a piece with a faces would be higher than the piece produced on the
few small knots. On the other hand, large knots or existing face.
defects will always be strength-reducing.
Step 5. Sweepy logs. (Figure 8) Saw the ears off in
Step 2. Choose the worst face of the log and begin one cut, unless there is useable lumber in the ears.
sawing on this worst face, producing short pieces of Then rotate to the belly, perhaps producing some short
lumber. Do not taper saw (or offset) the log. Rather, pieces of lumber. Sweepy, low-grade logs are a waste
take any and all taper out of the log on this worst face. of time.
The first piece will be low-grade and should be the
shortest piece that you can market. Long and narrow
is better than short and wide in most cases.

Step 3. After the worst side has a flat surface from end FIGURE 8
to end (and maybe one or two pieces of lumber have
been cut if the log is quite large), then go to the
opposite face, sawing parallel to the bark, producing
a full-length piece of lumber. Turning to the opposite
face reduces the workload when edging the pieces,
meaning less warp in drying and wider pieces will be
produced, compared to going to an adjacent face for
the second face.

On a good face, the opening width should typically be

6 inches, which means that the first piece of lumber
will be 6 inches wide and full-length. On a smaller log
(under 13 inches in diameter), the production of 4-inch
width for the first piece is probably better. Sweepy Log

Sawing Softwood Logs into Boards and Lumber for Remanufacturing

The log-sawing procedures are similar to the construction lumber sawing, except for the opening face size. On
a good face, the opening width should typically be 6-1/2 inches, which means that the first piece of lumber will
be 6-1/2 inches wide and full-length. On a smaller log (under 13 inches in diameter), the production of 4-1/2 inch
width for the first piece is probably better. The opening piece should probably be 4/4 thick, rather than 8/4, if there
is a market for 4/4. A butt log will have less defect in the center and so should probably not be converted into a
large timber, but should be sawn entirely into lumber.

14
14
1 1
SUMMARY
• Converting logs into lumber can be quite profitable and
rewarding if done properly and safely.

• Log storage should be as short as possible.

• Logs should be end-coated.

SAWING THE BEST LUMBER

• Logs should be opened on the worst face without
taper, or the best face with taper.

• Opening face widths should be 4-1/2 or 6-1/2 inches

for hardwoods, and 6 inches for softwoods, typically.

• Logs should be turned whenever an adjacent face

promises to have higher grade lumber.

15
15
16
16
 Drying the Best Lumber
2
PART 2

You have just finished sawing a log into lumber. Several pieces of lumber look fairly clear with a very good
grain pattern—these pieces may be potentially quite valuable and useful after they are dried. What needs to
be done in order to avoid any quality loss before the lumber is sold green-from-the-saw? Or, what are the next
steps in order to produce high-quality kiln-dried lumber ready for manufacturing into cabinets, furniture,
millwork, or other items? The following sections review the best procedures for drying lumber.

DRYING THE BEST LUMBER

WHY DRY LUMBER?
With only a few exceptions, dry lumber is more valuable than undried; kiln-dried is more valuable than
air-dried. The advantages of dry lumber include:

• Lumber under 22% moisture content (MC) has no risk of developing fungal stain, decay, rot, or mold.

• Dry lumber weighs over 50% less than wet lumber.

• Dry lumber is over twice as strong and twice as stiff as wet lumber.

• Nails and screws in dry lumber have higher holding power.

• Dry lumber is easier to glue.

• Dry lumber machines better than wet lumber (unless dried under 5% MC).

• Dry wood finishes easier.

• Dry lumber will shrink and swell in-use less than wet lumber that dries in-use.

MOISTURE CONTENT
The amount of water in lumber is measured as a In the living tree, wood typically has a moisture
percentage of the lumber’s oven-dry weight. For content of 75% or higher. (One-thousand board
example, in a piece of lumber weighing 10 pounds, feet of oak can weigh 4900 pounds. At 75% MC,
if there are 4 pounds of water and 6 pounds of dry there are 2100 pounds of water and 2800 pounds
wood, the moisture content is 67%. This value is of wood.) In order to use lumber for furniture, cabi-
calculated as the weight of water divided by the nets, millwork, and similar indoor uses, almost all of
oven-dry weight, times 100 to convert to percentage. the water must be removed—the removal process
So, in this example: 4 ÷ 6 x 100 = 67%. is called “drying.” For interior uses, the moisture
content should be 7%, which is equivalent to the
MC that wood will achieve in a relative humidity of
WATER IN WOOD 38% RH—the typical interior average RH for most
The living tree contains a great deal of moisture— homes and offices. (This means, using the previous
this moisture is the “life blood” of the tree, conduct- example, that all but 196 pounds of water must be
ing nutrients from the roots to the leaves, where the removed before the oak can be used.)
process of photosynthesis takes place. The water
content, incidentally, remains the same year-round—
the sap is not up in the summer and down in the
winter.
17
17
 AS SOON AS THE LUMBER IS SAWN . . .
Drying Risks
There are three major risks for lumber that has been freshly sawn:

• The lumber is subject to attack from insects.

• The lumber is likely to stain, including mold and mildew stains.
• The lumber is likely to crack, if exposed to sun or dry air for a few hours before stacking.

To keep lumber valuable and to avoid wasting this precious natural resource, lumber must be handled
correctly from the moment it leaves the saw. If handled improperly at the mill, especially the white woods like
maple and pine, can develop stain within 24 hours during warm weather (although often the stain itself doesn’t
show up until later). All species can develop value-reducing end splits within several days. Oak and beech are
especially susceptible to surface cracks (or checks).

Sorting Each layer of lumber is separated from the one

Once lumber is sawn, it is usually sorted into differ- above by wooden spacers called stickers. The stick-
ent size and value groups in order to facilitate han- ers, made of any DRY species of wood, are placed
dling and to obtain the highest quality. perpendicular to the lumber’s length. The width of
the layer is the length of the sticker. The stickers are
Lumber is always sorted by species, although spaced, starting at one end of the lumber, every 24
sometimes red and white oak will be mixed together. inches (although many operations use 12-, 16-, or
18-inch spacings in order to keep the lumber even
Lumber is always sorted by thicknesses, as well. It is flatter). The stickers keep the lumber flat and provide
not advisable to mix thicknesses in the same pile or space for air flow in the drying process. The stick-
stack of lumber. If thick and thin lumber is a problem, ers in one layer must be perfectly vertically aligned
then run the lumber through a single-headed (no greater than 1/2 inch variation) with the stickers
planer to achieve more uniform thickness. in layers below and above. A pile or stack is several
layers of stickered lumber.
Lumber is usually sorted by grade or quality clas-
sification; often only two sorts are used--valuable It would be best if the lumber within one stack is all
lumber (intended for furniture, cabinets, etc.) and the same length. However, if a few shorter pieces
the less valuable, industrial grade lumber. This grade are included (but never more than a 2-foot difference
sorting is done so that the higher-valued lumber can between the shortest and longest), then place the
be treated more carefully than the low-quality lumber. longer pieces on the outside edges of the layer and
Further, lower-quality lumber is often sold green; it is keep the shorter ones on the inside. The ends of the
rarely kiln-dried. shorter pieces should always be supported with a
sticker; therefore, an extra sticker may have to be
Stacking used in some layers.
Once sorted, the green lumber is stacked for drying
in order to maintain the highest quality (Figure 9). Once stacked, the lumber is placed in a good drying
Lumber is stacked in layers, with all the lumber in location (even if it will be sold in a few days) where
each layer being the same thickness. A layer is typi- the air can move through the package.
cally 4 to 6 feet wide. Narrow layers result in faster
drying, but also result in piles that can tip over more 5'
3/4"
easily. The length of the layer is the length of the
lumber, with the longer pieces being used on the
outside edges.
stickers

2'
to
2'
1/
1

FIGURE 9
18
18
 2
LUMBER DRYING
Initial Drying Kiln-Drying
The best results are obtained if the lumber is put into The process referred to as “kiln-drying” involves
a kiln or into controlled drying as quickly as possible. putting the lumber in a chamber in which the tem-
The second best approach is using a shed (a pole perature, humidity, and air velocity through the lum-
shed without walls is ideal) where the lumber is pro- ber are controlled. By controlling these three environ-
tected from direct rain and sun. Drying sheds require mental variables, the drying rate and the quality of
good air flow, so a barn or closed shed is usually too the lumber are controlled. Final moistures are as low
slow. On some species, adding fans to the shed will as 6% MC.

DRYING THE BEST LUMBER

help develop the lightest, brightest color. By shed-
drying before kiln-drying, the annual volume of lum- The smaller producer of kiln-dried lumber has several
ber dried in the kiln can be quadrupled, compared to major choices of equipment. As a broad generaliza-
kiln-drying green-from-the-saw. tion, solar-heated dry kilns are best for producing
under 25,000 board feet (25 MBF) of lumber annually.
Under 2 million board feet (2 MMBF), most
Air-Drying operations will find that an electrically operated
Remember: Slow drying, such as from slow airflow dehumidification (DH) kiln is best.
or high humidity, may result in stain. Fast drying,
such as from excessive airflow or low humidities,
can result in excessive cracking and splitting. The
air-drying process needs to be controlled as closely
as possible to avoid extreme conditions that may
result in quality loss.

The pile is usually stacked at least 12 inches above

the ground to avoid trapping moist air under the
pack. The pile should be covered on the top to
prevent direct exposure of the lumber to rain and
sunshine. More complete instructions on options
for quality air-drying are included in Air Drying of
Lumber, U.S. Department of Agriculture Handbook
No. 402. Although out of print, this handbook is
available in most large libraries and can be obtained
on inter-library loan from most smaller libraries.
Plans for building a solar kiln are available on the
Although air-drying is simple and easy, it is not Internet (www.woodweb.com). Solar kiln kits are
unusual to have in excess of 10% loss in quality available from Wood-Mizer. Often, a solar kiln will
due to the variability and extremes of the weather. pay for itself after drying just three or four loads of
Can you afford this? If not, consider shed-drying. (If lumber.
someone stole 10% of your lumber, wouldn’t you do
something about it?) As mentioned, in shed-drying, Dehumidifier kilns are more expensive than solar,
lumber is placed in an open shed, thereby avoid- but can provide top quality kiln-dried lumber year-
ing direct sunlight and rainfall. Drying rates can be round, regardless of whether the sun is shining or
regulated by using plastic mesh curtains--pull them not. Economic aspects of a dehumidifier kiln are dis-
closed during hot, dry weather; open them during cussed in Opportunities for Dehumidification Drying
cool or damp weather. Final moisture is typically over of Hardwood Lumber which is available from the
20% MC. Virginia Forest Products Association (P.O. Box 160,
Sandston, VA 23150). The cost of operating a DH kiln
With either air-drying or shed-drying, the lumber piles can be as high as $75 per MBF. However, the value
need to be placed on a flat foundation with at least added by drying is often $300 per MBF. The return
8 inches of clear area underneath. If the air under- on investment with a dehumidifier can be over 20%
neath the piles cannot flow out easily, high humidities after taxes.
will develop under the piles leading to poor drying
and a risk of stain. If the foundation is crooked, then Dryer operation is discussed in many texts. Three-
warped lumber is likely. to five-day short courses are conducted annually
throughout the U.S. and Canada. Look for
advertisements in trade magazines or contact state
forest products specialists.
19
19
 HOW DRY IS DRY ENOUGH?
Lumber should be dried to a final MC that is as close to the expected MC that the wood will achieve in use.
This guideline is established so as to avoid warping and size change problems in the final product. The MC
of wood in-use is related to the relative humidity (RH) that the wood is exposed to; temperature is irrelevant.
Different species have the same in-use MC if exposed to the same RH. A special term is used to relate RH to
MC in wood; the EMC (equilibrium moisture content) of air is numerically equal to the MC that wood will have
when exposed to a given RH. The following tabulation (Table 4) summarizes this relationship.

RULE: The basic rule for drying lumber is that the final MC in the kiln should be within 2% MC of the expected
EMC in-use to avoid moisture-related problems. Failure to observe this rule can easily result in manufacturing
losses exceeding $1000 per MBF, as well as loss of future sales and customers, and may even result in a law-
suit.

As a general rule of thumb, wood shrinks in width or thickness about 1% for every 4% MC change. (This is a
general rule, with some variation from species to species. Teak shrinks much less, 1% for 8% MC; oak shrinks
much more, 1% for 3% MC.) This means that if a 2-1/2-inch-wide piece of oak loses 3% MC, it will shrink
1% or 0.025 inches! This seems like a small amount of shrinkage, but when gluing, the maximum gap allowed
between two pieces of wood is only 0.006 inches. Further, if this oak piece is actually a piece of flooring in a
30-foot wide floor and the entire floor is losing 3% MC, the total shrinkage is 4 inches, which probably is dis-
tributed across the floor with objectionable cracks every foot or so.

Table 4 The relationship between humidity, EMC and wood use in North America.

RH MC EMC Condition
% % %
0 0 0 Oven-dry
30 6 6 Lower limit in most homes and offices
Lower limit for hardwood furniture and cabinet lumber
36 7 7 Average for hardwood furniture and cabinet lumber
44 8 8 Lower limit for softwood remanufacturing lumber
50 9 9 Upper limit in most homes and offices
Upper limit for softwood remanufacturing lumber
65 12 12 Average outside condition, winter and summer
Average for softwood construction lumber
80 16 16 Outside condition for coastal areas

Achieving Proper Final Moisture Content

Lumber needs to be properly stacked, with sticker openings being uniform in size. Narrow piles (6 feet or
under) have more uniform drying than wider piles. In dry kilns, uniformity of temperature, relative humidity, and
velocity is required. This uniformity is most critical when the lumber is above 40% MC and also when the lum-
ber is under 10% MC. In the kiln, uniform airflow and frequent airflow reversal (two hours) improve uniformity.
Equalization should be used for as long as required to achieve the desired uniformity of final MC—it may take
longer than 24 hours with some loads. The lumber should be as uniform in thickness and initial MC as possible.

Moisture samples need to be accurate and properly prepared. With as many as 5000 pieces of lumber in a
kiln, will just 8 or 10 samples give an adequate picture of the final MC? I suggest 30 samples be taken using a
hand-held moisture meter when the kiln is being unloaded to ascertain the correct final MC. When such sam-
pling is done, also look for areas in the kiln that are consistently wetter or drier than other areas. Make sure
that your moisture measuring technique can detect pieces under 6.0% MC—over-dried lumber is a serious
quality problem when machining or gluing.
20
20
 2

DRYING THE BEST LUMBER

ADDITIONAL QUALITY CHARACTERISTICS
OF THE DRYING PROCESS
Freedom from Checks and Splits Good Color
All lumber should be end-coated as soon as possible By far, the most critical factor determining lumber’s
after it is sawn. Good stacking and good control of color (or discoloration) is log freshness. Old logs
lumber lengths will help prevent the ends from drying have 20 times or more risk of developing stain–fun-
too quickly. High relative humidity at MCs above gal stains, sticker stains, browning, pinking, graying,
40% are critical. Moderate air flows and lower tem- and so on. Freshly sawn lumber requires low humidi-
peratures are also important. Above all, the drying ties, low temperatures and brisk velocities imme-
rate must be controlled to within narrow limits—the diately after stacking and until the lumber is under
precise rate depends on the species and thickness 30% moisture content to control stain. Narrow loads
of the lumber. and partially-filled dryers will help. Poor stacking and
exposure to rain increase the risk of stain.
Freedom from Warp
Except for cupping, and warp caused by bad stack- High Strength
ing (such as non-uniform sticker thickness, poor Low humidities and low dryer temperatures will
sticker alignment, or non-flat foundations), all warp maximize the strength. Other strength-lowering
results because of wood factors and sawmilling pro- factors, including bacterial and fungal effects and
cedures. Cup is a result of rewetting partially-dried species effects, are beyond our control.
lumber or over-dried lumber.
Good Machinability
Freedom from Casehardening Wood that is too wet will fuzz. Wood that is too dry
(Drying Stresses) (under 6% MC) will chip, split, and develop other
The procedures for proper stress relief (also called machining defects. Make sure that you monitor the
conditioning) require the rapid addition of moisture driest pieces of wood in the dryer as well as the wet
to the lumber surface when the lumber is warm. ones–don’t underestimate the effect of over-drying
Often the heat in the steam used for stress relief will on machining. Avoid temperatures over 160 F and
increase the kiln temperature above the required avoid very low humidities in the drying schedule.
level, leading to poor relief. Use of water to cool the (Conditioning or setting the resin at 180 F is accept-
steam or cooling the lumber prior to steaming should able, however.)
be considered. Using 180 F air temperature (often
called the dry-bulb temperature) is suggested. Note
that stress relief will be erratic if the lumber’s MC is Good Gluability
not uniform when stress relief begins. Water spray Good gluing requires accurate final MCs. Check for
systems can be used in lieu of steam spray. Solar pieces that are too wet (typically over 8.0% MC is
kilns do not require stress relief, as the nighttime too wet), and too dry (under 5.5% MC is too dry).
high humidities provide freedom from casehardening. Avoid temperatures over 160 F in the main drying
schedule. (Conditioning or setting the resin at 180 F
is acceptable, however.)
21
21
 MEASURING MC
Moisture content is a key parameter in wood processing. The MC values are measured daily when operating
a dry kiln. Depending on the MC, the temperature may be raised or the relative humidity lowered. In the dried
product, any change in MC is accompanied by warping, shrinkage (moisture loss), and swelling (moisture
gain). As a result, it is important to measure the MC accurately.

Moisture is measured in two ways: oven-drying and electrically.

Oven-drying Electric Meters

In the oven-dry test, a small piece of wood (called a The oven-drying test is a destructive test and
moisture section) representing a large piece of lum- requires 24 hours to get the reading. The MC can
ber is first weighed. The weighing is typically to the be measured rapidly and non-destructively by using
closest 0.01 ounces, so a postal scale is not accu- electrical methods. It was discovered years ago
rate enough. Then the moisture section is put in an that the electrical resistance is fairly well-related to
oven heated to 215 F. (A kitchen-type microwave MC. With the meter, pins are driven into the lumber
can also be used if the oven has a carousel tray, and and the resistance between the pins is measured.
is set to medium low for 20 to 40 minutes. Do not A second relationship was discovered between the
leave the oven unattended, however, as the section dielectric coefficient and the MC. Meters based on
sometimes may begin to smoke.) After approximately this principle use a flat plate that is intimate contact
24 hours, the section is weighed again, dried for one with the wood.
more hour, and then weighed again. If these two
final weights are the same, then all the moisture has Both types of meters are fairly accurate estimators of
been evaporated; the section weight is the oven-dry the MC. Each also has certain advantages and
weight. The MC is calculated using this formula: certain disadvantages. For example, the resistant
meter can measure a gradient, depending on how
far the pins are driven into the lumber. The resis-
(wet weight — oven-dry weight) tance meter also is not strongly affected by different
% MC = ------------------------------------------ x 100
(oven-dry weight) species. The dielectric meter is not affected by the
temperature of the wood. The dielectric meter can
also quickly scan the lumber’s surface looking for
wet spots or wet pieces. Anyone kiln drying wood
needs to have both types of meters—the best meter
An alternate formula is: is always the same one that your customer is using!

[ ]
(wet weight) The disadvantage of both meters is that they can-
% MC = ----------------------- —
(oven-dry weight)
1 x 100 not be accurately used above 30% MC. That means
that they cannot be used to run a kiln drying lumber
“green from the saw.” The oven-drying procedure is
the only reliable MC measuring system for kiln oper-
ation in most cases.

2
SUMMARY
• Lumber drying is an easy, profitable manufacturing technique.

• Air-dried lumber must be stacked correctly, protected from the

elements, dried at the correct rate, and dried to the correct MC.

• If proper procedures are used, the lumber will be flat, bright, and
free from cracks, checks, and splits.

22
22
 Additional Resources
3
PART 3

Contact the sources listed to determine availability and cost.

Most of the items listed will require prepayment.

Sawing and Grading Drying

Rules for the Measurement & Inspection of Drying Source Book: 40 Years of Drying

ADDITIONAL RESOUR CES

Hardwood and Cypress Experience
Written by and available from NHLA, Edited by E. M. Wengert and R. Toennisson.
P.O. Box 34518, Memphis, TN 38184. Available from Forest Products Society, 2801
Marshall Ct., Madison, WI 53705.
NHLA Inspection School Manual
Written by and available from NHLA, Drying Hardwood Lumber,
P.O. Box 34518, Memphis, TN 38184. By J.Denig, G. Wengert and W. Simpson.
Available (free) from Publications Department, Wood
What is hardwood? How is it graded? Eduction & Resource Center, 301 Hardwood Lane,
(14-minute video) Princeton, WV 24740.
Produced by and available from NHLA,
P.O. Box 34518, Memphis, TN 38184. Drying Oak Lumber,
By E.M. Wengert.
Basics of hardwood lumber grades Available from University of Wisconsin--Forestry
(10-minute video) Dept., 1630 Linden Dr., Madison, WI 53706.
Produced by and available from NHLA, P.O. Box
34518, Memphis, TN 38184. Opportunities for Dehumidification Drying of
Hardwood Lumber
Small Sawmill Handbook: Doing It Right and By E.M. Wengert & Others
Making Money Available from Virginia Forest Products Association,
Written by Joe Denig P.O. Box 160, Sandston, VA 23150.
Available from the Forest products Society,
2801 Marshall Ct. Madison, WI 53705. Applied Drying Technology, 1988 to 1993; and
Applied Drying Technology, 1978-1988,
Sawing, Edging and Trimming Hardwood Lumber By M. R. Milota and E.M. Wengert.
By Joe Denig and Gene Wengert. Available from Forest Products Society, 2801
Available from the Forest products Society, Marshall Ct., Madison, WI 53705.
2801 Marshall Ct. Madison, WI 53705.
Dry Kiln Operator's Manual
Lumber yard insects (22-minute video) Edited by W. T. Simpson and Others.
Produced by and available from NC State University, Available from Forest Products Society, 2801
Campus Box 7603, Raleigh, NC 27695-7603. Marshall Ct., Madison, WI 53705.

Wood Using Industries Dry Kiln Schedules for Commercial Woods

Directories are usually issued by most state every By R.S. Boone and Others. Available from Forest
few years. Contact the state Department of Natural Products Society, 2801 Marshall Ct., Madison, WI
Resources, Forest Products Utilization Specialist. 53705.

Web Site: www.woodweb.com Design and Operation of a Solar-Heated Dry Kiln

(Sawing and Drying Discussion /Message Board). By Brian Bond.
Publication 420-030, Dept. of Wood Science and
Sawmill & Woodlot Management magazine Forest Products, Virginia Tech, Blackburg, VA 24061.
(targeting small producers).
Subscription information available at Web Site: www.woodweb.com
www.sawmillmag.com (Sawing and Drying Message Board)

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