Conventional kiln drying

More than 75 percent of the existing hardwood dry kilns in the United States are steam heated, are humidity controlled and have reversible fans inside the kiln.

These kilns will typically hold several thousand board foot of lumber. Temperatures inside the kiln range from 120 degrees Fahrenheit to 190 degrees Fahrenheit, depending on the stage of drying. Although there are kilns in which temperatures reach up to 240 degrees Fahrenheit. Usually, these are limited to softwoods that dry very easily and low-value hardwoods.

Both temperature and humidity are controlled by either fully automated or semi-automated systems. These systems contain devices that monitor conditions in the kiln and lumber and adjust interior conditions accordingly.

The rate at which the lumber dries is controlled to minimize or eliminate defects caused by drying. Defects include discoloration, warping, cracking, splitting and surface checking (small openings on the faces of the boards). In extreme cases, drying causes honeycomb, internal splits that cannot be seen on the surface, or collapse.

Other forms of heat include direct-fired hot air, electricity, solar, and hot water or oil. Direct-fired hot air kilns usually are limited to softwoods and relatively low-value hardwoods because precise humidity control is difficult — if not impossible — to obtain in the kilns.

Usually, electric heat is limited to either dehumidification kilns or to one of the vacuum drying processes. Solar heat can be used as supplemental heat in some areas. Some successful designs of solar kilns intended for hobby use are available at 500 to 1,000 board foot capacity. Usually, commercial solar kilns are restricted to tropical areas, to areas where conventional energy sources are not available, or small, home-based businesses. Neither hot water nor hot oil systems find much use in commercial kilns because of low heat transfer efficiency.

Air movement in the kiln is controlled by reversible fans and baffles. Air movement is necessary to carry moist air away from the surface of the boards and to carry heat to the boards. The air flow is periodically reversed automatically to ensure even drying across the width of the kiln.

Baffles are used to force the air through the lumber packages across the surface of the boards. Place baffles at the top, bottom and ends of the kiln. Adjust the baffles to accommodate size variations in lumber packages in the kiln and to account for the lumber shrinkage that occurs during the drying process.

While specific details on humidity and temperature control systems are beyond the scope of this publication, most systems rely on measuring the dry-bulb and wet-bulb temperatures in one or more places inside the kiln.

Use a standard thermometer to measure the dry-bulb temperature. Measure the wet-bulb temperature by placing a wet cotton wick over a conventional thermometer. Water evaporating from the cotton wick cools the thermometer.

The wet bulb temperature will always be lower than the dry bulb temperature. The difference between these readings is called wet-bulb depression. It is a measure of the drying force applied to the lumber.

The relative humidity inside the kiln — or anywhere — is calculated using these two measurements. Accurate humidity control in the kiln is mandatory for properly drying hardwood lumber.

Periodically sampling the actual moisture content of the lumber in the kiln ensures that changes in temperature and humidity settings keep the lumber drying at the maximum safe rate schedule. USDA Agriculture Handbook 188, Dry Kiln Schedules for Commercial Woods, contain several typical schedules for various species and thicknesses of lumber.

Measurement can be done either by weighing predetermined sample boards or by using a hand-held, battery-powered moisture meter. In either event, several measurements must be taken throughout the kiln to get reliable readings.

While there are no hard and fast rules about punctuation, there are good style guidelines. This is a list of our ten most commonly used punctuation marks and a guide to their use.

10. Comma

Use commas to separate independent clauses in a sentence, for example:

The game was over, but the crowd refused to leave.

Yesterday was her brother’s birthday, so she took him out to dinner.

Use commas after introductory words, phrases, or clauses that come before the main clause:

While I was eating, the cat scratched at the door.

If you are ill, you ought to see a doctor.

NOTE: You should not do the reverse of this. For example, the following two cases are wrong:

The cat scratched at the door, while I was eating.

You ought to see a doctor, if you are ill.

Introductory words that should be followed by a comma are: yes, however, and well. For example: Yes, you can come to the party

Use a pair of commas to separate an aside from the main body of the sentence. For example:

John and Inga, the couple from next door, are coming for dinner tonight.

You can test this by removing the aside from the sentence. If the sentence still reads correctly, you have probably used the commas as you should. In the case above, this would render: John and Inga are coming for dinner tonight.

Do not use commas to separate essential elements of the sentence. For example:

Students who cheat only harm themselves.

The baby wearing a yellow jumpsuit is my niece.

The Oxford Comma

I prefer the Oxford comma when dealing with lists. It is also known as the Serial Comma or the Harvard Comma. The Oxford comma is much more widespread in American English than British English. When using the Oxford comma, all items in a list of three or more items are separated. For example:

I love apples, pears, and oranges.

Note the comma after “pears”. Many people prefer not to use this style and will omit the final comma. We call this the Oxford comma because it is the standard method taught at Oxford University.

Use commas to set off all geographical names, items in dates (except the month and day), addresses (except the street number and name), and titles in names.

Birmingham, Alabama, gets its name from Birmingham, England.

July 22, 1959, was a momentous day in his life.

Occasionally, you will see a comma between a house number and street. This is not wrong, it is just old fashioned. It is not done in modern times, however.

Use a comma to shift between the main discourse and a quotation.

John said without emotion, “I’ll see you tomorrow.”

“I was able,” she answered, “to complete the assignment.”

Use commas if they prevent confusion:

To George, Harrison had been a sort of idol.

9. Period or Full Stop

The primary use of a period is to end a sentence. Its second important use is for abbreviations. There are stylistic differences here. I will discuss both.

Fowler

Martin Fowler, author of Modern English Usage, says that we should place a period at the end of an abbreviation only when the final letter of the abbreviation is not the final letter of the expanded word. For example:

Jesus Christ was born c. 4-6AD

The abbreviation is for the word “circa” – as it ends in an ‘a’ and the abbreviation is normally ‘c’ – we include the period.

Mr Jones was happy to see his wife

St Patrick lived in Ireland

In the first case above, “Mr” is an abbreviation for mister. Because mister ends in an ‘r’ and the abbreviation includes that ‘r’, we omit the period.

Other

The other use of the period for abbreviations is to always include the period, regardless of whether the final letter is included.

Mr. Jones was happy to see his wife

If an abbreviated phrase is pronounced, we do not include periods. For example: NASA is correct, N.A.S.A is incorrect. In some cases the periods are omitted even when the word is not pronounced, usually because it is a very commonly known term. For example: UCLA (University of California, Los Angeles).

In the case of a word like et cetera (etc.,) we always include the period.

8. Question Mark

The question mark is a fairly easy punctuation mark to use. It has one use, and one use alone. It goes at the end of a sentence which is a question. For example:

How many will be at the party?

you do not include a period when using a question mark. You also do not use a combination of question marks and exclamation marks in formal writing, though this is gaining acceptance in informal writing – particularly on the internet.

One thing to be careful of is to not include a question mark when it is not needed:

WRONG: I wonder how many people will come to the party?

While you are expressing a thought that seems to require an answer, you are doing so with a statement. This is the most common mistake made when using a question mark.

7. Exclamation Mark

Only use this when issuing a command or speaking forcefully! As in the case of the question mark, do not follow this with a period and do not combine it with other punctuation marks. Oh, and only one is needed. Two or three exclamation marks in a row is completely unnecessary.

6. Quote Marks

Quotation marks are used to quote another person’s words exactly, whether they be spoken, or written. For example:

John said, “We are going shopping.” – note the capitalization of “We”. You should do this unless you are quoting in a run-on sentence:

John said “we are going shopping” because they had no milk. Note the omission of the comma in this case also.

If you are quoting a person who is quoting another person, use a single quotation mark like this:

John said, “My neighbor yelled at me today! He said ‘get off my lawn!’”

When introducing a quotation after an independent clause, use a colon and not a comma to begin:

As D. H. Nachas explains, “The gestures used for greeting others differ greatly from one culture to another.” (not an independent clause)

D. H. Nachas explains cultural differences in greeting customs: “Touching is not a universal sign of greeting. (this is an independent clause)

Quotation marks can also be used to denote irony or sarcasm, or to note something unusual about it:

The great march of “progress” has left millions impoverished and hungry.

Punctuation with quotations

Punctuation that belongs to the original quote should be inside the quote marks. Punctuation relating to the entire sentence should be outside.

Philip asked, “Do you need this book?”

Does Dr. Lim always say to her students, “You must work harder”?

Always put colons and semicolons outside quotes. Put commas and periods inside quotations unless followed by parenthesis:

He said, “I may forget your name, but I never remember a face.”

Mullen, criticizing the apparent inaction, writes, “Donahue’s policy was to do nothing” (27).

5. Colon

A colon should be used after a complete statement in order to introduce one or more directly related ideas, such as a series of directions, a list, or a quotation or other comment illustrating or explaining the statement. For example:

The daily newspaper contains four sections: news, sports, entertainment, and classified ads.

The strategies of corporatist industrial unionism have proven ineffective: compromises and concessions have left labor in a weakened position in the new “flexible” economy.

The colon is also used to separate chapter and verse from the bible (I Parlipomenon 12:30), to separate hours, minutes, and seconds: 13:49:08, and as eyeballs in smiley faces.

4. Semicolon

Use a semicolon to join related independent clauses in compound sentences. For example:

Jim worked hard to earn his degree; consequently, he was certain to achieve a distinction.

Jane overslept by three hours; she was going to be late for work again.

The semicolon is also used to separate items in a series if the elements of the series already include commas. For example:

Members of the band include Harold Rostein, clarinetist; Tony Aluppo, tuba player; and Lee Jefferson, trumpeter.

3. Apostrophe

The apostrophe has three uses:

1) to form possessives of nouns
2) to show the omission of letters
3) to indicate certain plurals of lowercase letters.

Forming possessives

the boy’s hat

three day’s journey

If the noun after “of” is a building, an object, or a piece of furniture, then no apostrophe is needed. For example: The car door.

Showing omission

He’ll go = He will go

could’ve = could have (Not “could of”!)

Forming plurals

Apostrophes are used to form plurals of letters that appear in lowercase. For example:

Mind your p’s and q’s

2. Parentheses

Parentheses are occasionally and sparingly used for extra, nonessential material included in a sentence. For example, dates, sources, or ideas that are subordinate or tangential to the rest of the sentence are set apart in parentheses. Parentheses always appear in pairs.

Before arriving at the station, the old train (someone said it was a relic of frontier days) caught fire.

1. Dash or Hyphen

Dash

Use the dash to emphasize a point or to set off an explanatory comment; but don’t overuse dashes, or they will lose their impact. A dash is typically represented on a computer by two hyphens with no spaces before, after, or between the hyphens.

To some of you, my proposals may seem radical–even revolutionary.

It is also used for an appositive phrase that already includes commas.

The boys–Jim, John, and Jeff–left the party early.

As you can see, the dash can be used in the same way as parentheses.

Hyphen

Use a hyphen to join two or more words serving as a single adjective before a noun:

chocolate-covered peanuts

Don’t use the hyphen when the noun comes first:

The peanuts are chocolate covered

Use a hyphen with compound numbers: Forty-five

You should also use a hyphen to avoid confusion in a sentence:

He had to re-sign the contract
He had to resign his job

Use a hyphen with the prefixes ex- (meaning former), self-, all-; with the suffix -elect; between a prefix and a capitalized word; and with figures or letters:

ex-husband
self-assured
mid-September
all-inclusive
mayor-elect
anti-American
T-shirt
pre-Civil War
mid-1980s

Sourced under fair use from the Purdue University Online Writing Lab

Wood veneer

In woodworking, veneer refers to thin slices of wood, usually thinner than 3 mm (1/8 inch), that typically are glued onto core panels (typically, wood, particle board or medium-density fiberboard) to produce flat panels such as doors, tops and panels for cabinets,parquet floors and parts of furniture. They are also used in marquetry. Plywood consists of three or more layers of veneer, each glued with its grain at right angles to adjacent layers for strength. Veneer beading is a thin layer of decorative edging placed around objects, such as jewelry boxes. Veneer is also used to replace decorative papers in Wood Veneer HPL. Veneer is also a type of manufactured board.

Veneer is obtained either by "peeling" the trunk of a tree or by slicing large rectangular blocks of wood known as flitches. The appearance of the grain and figure in wood comes from slicing through the growth rings of a tree and depends upon the angle at which the wood is sliced. There are three main types of veneer-making equipment used commercially:

• A rotary lathe in which the wood is turned against a very sharp blade and peeled off in one continuous or semi-continuous roll. Rotary-cut veneer is mainly used for plywood, as the appearance is not desirable because the veneer is cut concentric to the growth rings.
• A slicing machine in which the flitch or piece of log is raised and lowered against the blade and slices of the log are made. This yields veneer that looks like sawn pieces of wood, cut across the growth rings; such veneer is referred to as "crown cut".
• A half-round lathe in which the log or piece of log can be turned and moved in such a way as to expose the most interesting parts of the grain.

Each slicing processes gives a very distinctive type of grain, depending upon the tree species. In any of the veneer-slicing methods, when the veneer is sliced, a distortion of the grain occurs. As it hits the wood, the knife blade creates a "loose" side where the cells have been opened up by the blade, and a "tight" side.

Types of veneers

There are a few types of veneers available, each serving a particular purpose.

• Raw veneer has no backing on it and can be used with either side facing up. It is important to note that the two sides will appear different when a finish has been applied, due to the cell structure of the wood.
• Paper backed veneer is as the name suggests, veneers that are backed with paper. The advantage to this is it is available in large sizes, or sheets, as smaller pieces are joined together prior to adding the backing. This is helpful for users that do not wish to join smaller pieces of raw veneers together. This is also helpful when veneering curves and columns as the veneer is less likely to crack.
• Phenolic backed veneer is less common and is used for composite, or manmade wood veneers. Due to concern for the natural resource, this is becoming more popular. It too has the advantage of being available in sheets, and is also less likely to crack when being used on curves.
• Laid up veneer is raw veneer that has been joined together to make larger pieces. The process is time-consuming and requires great care, but is not difficult and requires no expensive tools or machinery. Veneers can be ordered through some companies already laid up to any size, shape or design.
• Reconstituted veneer is made from fast-growing tropical species. Raw veneer is cut from a log, and dyed if necessary. Once dyed, the sheets are laminated together to form a block. The block is then sliced so that the edges of the laminated veneer become the “grain” of the reconstituted veneer.
• Wood on Wood Also called 2-ply is a decorative wood veneer face with a utility grade wood backer applied at an opposing direction to the face veneer.

Patterns

There are a number of "patterns" common to veneered work. This refers to the way the veneers are laid up.

• A: Book matched: where the veneers are opened from the flitch much like the pages of a book.
• B: Slip matched: where the pieces are joined together in the order they come from the flitch, and have the same face kept up.
• C: Radial matched: where the veneer is cut into wedge shaped pieces and joined together.
• D: Diamond matched: where the pattern formed is diamond shaped.

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