How To Dry Wood for Woodworking Projects – Expert Tips

We all know lumber comes from trees, but trees were not designed for lumber. Man has to take something that naturally grows in a cylindrical shape, dry it out and make it rectangular. It’s a peculiar process that requires patience.

Freshly cut trees must be properly dried. Each time the wood goes from log to lumber, outside to inside or humid to dry, care must be taken to manage that change. If that doesn’t happen, this beautiful biological material may grow or shrink.

Plus, wood moves with changes in humidity throughout the year. In the summer, seasoned furniture-makers build drawer faces in cabinet frames tighter than they would in the winter, knowing that these boards will shrink as temperatures drop and leave gaps. The converse is true in the winter; it needs to be built loosely; otherwise, the drawer will swell and stick in the summer.

Read on for tips on how to dry wood to help you keep your woodworking projects crack- and gap-free.

Why Proper Wood Drying Matters for Woodworking

Whether you’re prepping timber straight from a felled tree or double-checking that store-bought boards are ready to work with, knowing how to dry wood properly can save your projects from costly mistakes.

Allow air movement

When freshly cut, wood stacked without air space around the logs can develop mold and mildew, resulting in stains or decay. So sawyers utilize a method called stacking and stickering, which creates an alternate stack of dry 1-in. x 1-in. sticker lengthwise every 16 inches or so between layers of wet wood.

Each set of stickers is placed above the previous layer, ensuring the wood dries flat and smooth. This is one of the best air-drying wood tips that I also follow. I always sticker wood if I need to store it longer than a couple of days, even if it’s technically dry. While it won’t develop mold, any plank of wood where moisture is only allowed to escape from one face can warp or cup, making furniture joinery difficult.

Use a moisture meter

Wood from the lumberyard is usually kiln dried. But how dry is it? It depends on how it was stored and for how long before you bought it.

While most lumberyards dry wood to eight to 10 percent moisture content (MC), wood stored indoors tends to remain dry. Lumberyards with exterior storage can have lumber with a wider range of MC. It’s best to measure the moisture content with a moisture meter like the mini-LIGNO E/D, which has pins that stick in the face or ends of the lumber.

In the Midwest, we have wild fluctuations in humidity, but I aim for seven to nine percent moisture once the boards are in my shop for a week. The ends of boards dry quickly; to get an accurate reading from the end of a board, you’ll need to cut about three inches off to expose the inside.

If you are drying wood at home, pinless moisture meters like the Lignomat Scanner SD are simply waved across the top of the lumber to get a moisture reading. However, to ensure accuracy, you must input the wood species.

Air drying

As a general rule of thumb, air drying freshly cut wood takes about one year per inch of thickness before it’s ready to be milled into usable lumber.

• The internal structure of wood—think of it like a bundle of drinking straws—allows moisture to escape most easily from the ends, while moisture in the center gradually seeps out through the board’s face or edges.
• As the wood dries, it tends to shrink and can warp, cup or bend, depending on the part of the tree from which it comes and the drying method.
• The knots in the grain almost always bring further unpredictable twisting.
• It is crucial to note that not all wood types respond in the same way.
• Some, like beech, are known for their tendency to warp dramatically, while others like walnut are more dimensionally stable.

To keep track of your drying timeline, use a permanent marker to date each piece—it’s a simple trick that pays off later.

Build a solar kiln

Trees recently milled into lumber are 100 percent wet. A solar kiln is a great option to accelerate the drying process. Creating a south-facing enclosed shed with a clear plastic roof that heats up to 130°F or more will speed drying along.

One must be careful to not dry the wood too fast, or it will warp and crack. Inside the kiln, fans and vents manage the moisture properly and keep the space inside the kiln (AKA the volume) from heating too much. The state of Oregon published a thorough overview on its website.

Seal the ends of wet wood

Wood loses its moisture most quickly at the ends of a board, so ends dry out, shrink and crack faster than the middle of the plank. Applying Rockler’s Green Wood End Sealer seals the end grain, making moisture transpire more slowly than if left unsealed. I’ve also used wood glue, thinned with water, or even leftover latex paint in a pinch.

Chop ends to check for hidden cracks

End cracks occur on almost every piece of lumber, some worse than others. Sometimes cracks are visible and obvious, while others are imperceptible to the naked eye.

After wood is dry and ready for joinery, there’s a great trick to finding these invisible cracks. When processing the lumber to length, chop a one-inch block off the end of the board and gently drop it on the shop floor. If it breaks, there is a hidden crack! Repeat until the dropped piece doesn’t break. Then measure and cut the other end of the board to appropriate length.

Air Drying vs. Kiln Drying – Pros and Cons

Air drying wood at home

Air drying is an economical and handy way of drying wood naturally. Here are some tips on drying wood in open air:

• Timeframe: Requires an approximate year of drying per inch of thickness.
• Location: Pick somewhere in the shade, dry and ventilated. For example, a shed with covers or a garage.
• Stacking: It is stacked with spacers that are 1″ x 1″ in size placed in between to allow for air to come in contact with all sides of the wood.
• Protection: Covers from above with a tarp in case of rain, but keep the sides open for air circulation.

Kiln drying for beginners

Kiln drying is fast and controlled but must be done with equipment or a small solar kiln built.

• Speed: Reduces drying days to weeks from months.
• Control: Provides means of evenly drying, less chance of mold, or insect damage.
• Caution: If wood is dried too quickly, cracking or internal stresses may be created.

Step-by-Step Guide to Air Drying Wood

Drying wood in the air is a natural and inexpensive approach to lower its moisture content and get it ready for long-term use.

• To lower the chance of warping or breaking, mill the logs into boards right after you cut them down.
• Find a shaded, well-ventilated spot that is out of the rain and the sun.
• Put boards in layers and put evenly spaced stickers (little wooden strips) between them to let air flow.
• Use pallets or beams to lift the wood off the ground so it doesn’t soak up moisture and air can move better.
• Put a waterproof cover or tarp over the top of the stack, but leave the sides open so air may flow through.
• Use a moisture meter to keep track of how much moisture is in the wood. Depending on the type and thickness of the wood, air drying can take anywhere from a few months to more than a year.

How to use a moisture meter for accurate results

To find out when your wood is ready to use, you need to know how to use a moisture meter correctly. Here are some tips.

• Choose the right meter: use a pin-type for readings inside or a pinless for readings on the surface.
• If your meter needs it, calibrate the gadget based on the type of wood.
• To find out if the boards are drying unevenly, measure in a few different places on each board, such as the ends and the center.
• To use the meter correctly, either fully insert the pins or lay the pinless sensor flat on the surface.
• To make sure the wood is evenly and properly dry, look for readings that are within 1–2% of each other.

A Note About Construction Lumber

It’s happened to everyone: wandering the aisles at the home store and finding a stack of beautiful, perfect 2x10s or 2x12s. Straight-grained, knot-free pine would make a great bookshelf, but don’t build it right away.

Framing lumber is usually only kiln dried to 14 or 16 percent moisture, so significant shrinking and cracking is still to come. It’s best to take this wood and bring it into your shop for a week or longer so the wood can achieve a MC appropriate for furniture.

FAQ

What is the best way to dry wood at home?

You can dry wood at home using air drying or a simple DIY kiln. The most economical and often the easiest, is just air drying. Stack the wood elevated off the ground, use stickers (wooden sticks) between layers to aid air circulation and protect it from rain and direct sun. There are also small solar kilns that will get you there faster. For the beginners, drying in a kiln can be an ideal way to hasten the process and have greater control over humidity levels and temperature.

How long does it take to dry wood?

Generally, wood that is exposed to air drying is one year per inch of thickness. It could take longer, but it depends on the type of wood, weather and conditions in the drying area. Hardwoods take even longer and softwoods dry even faster. Fans, as well as laying the stack in a shady and breezy location, can speed up drying.

What prevents the wood from cracking when drying?

If you’re looking to learn how to stop wood from cracking, the secret is to slow down the loss of moisture from the ends of the boards. Coat the ends with wood sealer, wax, or even the remainder of the paint to minimize fast evaporation. Storing the wood in a dry, shaded area with air circulation can also minimize internal stress, reducing the risk of the wood cracking.

Is kiln drying a good option for beginners?

Absolutely. Kiln drying for beginners is a game-changer for wood drying. With a simple solar kiln design, you can dry a variety of lumber in a fraction of the time it takes with the more complex shop-built dehumidifying kiln. Just make sure not to dry the wood too fast, or you’ll invite warping or checking. Beginners should follow guides to carefully monitor humidity and airflow in the kiln.

Source:

• OWIC: “Solar Kiln Plans–Processing Trees to Lumber for the Hobbyist and Small Business”
• PennState Extension: “Air Drying Lumber from Your Own Forest”
• The Wood Database: “Drying Wood At Home”