Rob Cosman's Winding Sticks

Winding sticks are a time honored jig that helps you evaluate if the surface of a board has any wind or twist.  To give you an accurate reading the winding sticks must be precisely made.  Here are why my winding sticks give you the professional results you demand:

• Made from extremely stable, torrefied wood. The wood color ranges from a light tan to a dark brown.

• Torrefied wood has undergone a high-heat treatment changing the cellular make-up of the wood so that the wood does not react to moisture.

• Precisely milled flat, square, and parallel to give accurate measurements.  

• The sticks are tapered narrow top and a wide bottom to increase stability when upright.

• 2" Tall x 20" Long x 5/8" Wide at the base. 

• Inlaid with a white wood, American Holly, in the corners and centers for easy and accurate readings. 

• Pins mate the sticks together for storage.

What is Torrefied Wood?

Torrefaction is not a new process. In the 8th century the Vikings torrefied the wood they used to build their ships, enhancing its stability and durability.  Scandinavian countries have been improving this age-old procedure since the 1930s.   

The wood is gradually pre-heated in a conventional kiln lowering the moisture content to between 6% and 10%.  After that the wood is heated at a very high temperature (between 190C to 240C), in a torrefaction kiln (autoclave) under pressure and in a low oxygen atmosphere (to prevent combustion), lowering the moisture content to almost 0%. The length of the process, as well as the temperature degree sustained, depends on the species and the desired color of the wood.  Finally, the wood is placed in a conditioning chamber where the temperature is gradually lowered by controlled steam injection and the moisture level of the product is increased to between 3% and 6%, giving back the wood’s natural flexibility.

This torrefcation process cooks off all the volatile elements in the wood (sugar, oils, and water) leaving behind a mineral residue and changing the wood’s molecular structure from open to closed celled.  This has three significant results important to woodworkers:  It gives the wood a rich amber color, stabilizes  the wood, and significantly improves it’s durability (resistance to rot).

When properly torrefied, the wood will not absorb water even when submerged for extended periods of time!  It is this property that makes torrefied wood incredibly stable.   Normally wood moves due to the absorption and release of moisture from the atmosphere as the seasons change.  All woodworkers understand this and account for wood movement in their designs. Torrefied wood changes this age-old requirement to account for wood movement due to moisture.