Fine Woodworking 2007 Building Furniture

W

hen I was still wet behind the ears as a

furniture maker, I once built a tabletop that

shrank so much against the breadboard ends

that it cracked.

I hadn’t taken into account the amount of

shrinkage the top would experience in the dry

air of the first winter. As it tried to shrink against the pegs of the

breadboard ends, two fine cracks opened up. It didn’t matter

how old the wood was or if it was kiln- or air-dried, it was

doing what wood forever will do—shrink and swell as it loses

or absorbs moisture from the atmosphere.

Despite modern glues, well-engineered joinery, and sealing

finishes, wood’s moisture content demands attention if you want

your work to last. Out of necessity, I’ve developed strategies

for dealing with moisture content as I’m seasoning the stock,

milling the wood, and building my furniture.

Seasoning and milling the stock

When lumber arrives in my shop, I stack it loosely on end against

a wall or on horizontal racks with stickers between the layers

so that air can move through the pile. Then I leave it alone. The

simplest way to reduce potential moisture problems is to let the

wood acclimate to the shop well in advance of starting a project.

In the winter, softwoods can acclimate in a week, and dense

hardwoods in a few weeks. If I need to speed the process, I rough-

cut parts and stack them in the gentle warmth above my shop

heater. Even in the summer, when the atmosphere is at its most

humid, the wood dries further. The longer it adjusts, the better.

For a long time I have relied on empirical methods that I’m sure

past cabinetmakers also used. Dry wood feels warm, and produces

more crumbly plane shavings than wetter wood. For thick stock, I

drill into a waste section to see if the borings seem dry.

Only recently have I also begun to use a moisture meter to know

exactly how quickly the final drying is progressing. A simple meter

that uses two pins inserted into the wood surface costs about $125.

My milling strategy is aimed at producing stable parts with the

same moisture content inside as on the surface. Wood not fully

acclimated, especially thick stock, can be wetter inside than out.

A few days of rain, however, and very high humidity, can leave

Step 1: let new

Stock adjuSt

to your Shop

When bringing wood into the

shop, allow the moisture content

to balance with shop condi-

tions. The easiest way is to

stack boards vertically (above)

or horizontally on racks in the

shop for a few weeks. A moisture

meter can be used to check the

seasoning process by compar-

ing readings from newly arrived

stock (top right) with an average

reading from boards that have

already acclimated to the shop

(bottom right). Finally, mill stock

in stages. Leave extra material

when ripping boards to width

(below) or surfacing them with

the jointer and planer. Varia-

tions in moisture content within

boards can cause them to warp

after milling. Excess material

allows room to correct this later.

14 F I N E W O O D W Or kI Ng Photos: Steve Scott

Living with wood

movement

Shop environment iS the key

b y G a r r e t t H a c k

getting started

FWSIP08BF_GS.indd 14 6/6/07 12:25:29 PM