Category: Wood Characteristics

Cupping is referred to when a boards edges start to curl up or down relative to the center of the board (fig 13).  This is caused by an imbalance of moisture in the wood.  Your best reference of cupping may be your deck.  Because the board is exposed to constant sun, wet, cold, and hot conditions on the exposed side of the board, and very little sunlight and moisture on the bottom, the board cup’s.

This allows more moisture to sit on top of the board because the sides are higher than the center, thus creating more problems.

What to do?

Amish craftsmen are aware of the problem and take steps to prevent cupping.  First, they glue boards with the grain patters going opposite directions.  They also seal the top AND the bottom of the boards.  This limits the amount of moisture that can penetrate the wood.  The client must also do their part by keeping moisture off the wood and if it’s outdoor Amish furniture they should use a wood sealer.

Swelling occurs when the ambient moisture level in your home changes. This is often found during summer months in homes with no climate control (no air conditioning). The wood is constantly trying to stay balanced with the humidity level of the room. If the Amish furniture is not sprayed with a film finish (conversion varnish) the wood will take moisture until it balances with the humidity level of the room, causing swelling.

Consumer note: One place the wood swells is the solid wood leaves of dining tables. This is natural and will change through the seasons. This is not an Amish Craftsman defect, just nature taking it’s course.

This is a basic overview of the woods that Amish furniture craftsmen use. If you would like more info check out your local States DNR website for specific tree details.

One of the challenges of solid wood furniture is controlling the wood from splitting (fig 109).  Amish craftsmen work hard to prevent this from happening.  The process actually starts when the log is cut.  The ends of the log, which are shaped like little straws carrying nutrients through the tree, are more porous and easily shed moisture.  This imbalance in the moisture content of the wood can cause splitting.

Splitting also occurs when the Amish craftsmen does not get enough glue on the seam of two boards.  It should be noted that glue is actually stronger than the wood.  Often a split or crack will form next to the glue joint, but not on the joint.

What to do?

The Amish have done most of the work for you by sealing the end grains with Conversion Varnish. This stops the flow of most moisture into the wood.

The consumer’s job is to limit the Amish furniture from direct sunlight. The sun is trying to dry the top of the wood faster than non exposed areas. The consumer must also control the humidity levels in the home.  From summer to winter your home’s moisture will change.  Your furniture was built to “move” with the changes by the Amish craftsman building floating panels in the doors, using screws to connect pieces were the grain patterns change direction, etc.

There is a tremendous amount of thinking, along with superior craftsmanship, that goes into each piece of Amish built furniture.

This is a planked top table with breadboard ends. The planked boards run perpendicular to the end pieces and the dowels you see are how these 2 large pieces attach with a dado joint.

What you may see over time is Mother Nature working in tandem with your solid wood table. This is dependent on the conditions of your home and the humidity levels that you are experiencing, whether you will see changes in your table.

Even after the tree is cut down the wood will take on and release moisture, which is called expansion or contraction. Breadboard tables were designed for this purpose. The circles that you see cut are expansion and contraction joints hidden below the surface of the wood. Your table can expand up to a 1/8” of an inch throughout the season. Simply put a touch of stain to cover up any exposed unfinished wood.