Ukulele Tonewood Care
Acclimating, Storing, and Flattening Tonewood
*-Weights are approximate. Use enough to keep panels flat
Tonewood panels and billets should always be stored flat with weight on top to keep them flat. Unless totally sealed, wood takes on and releases moisture, which causes expansion and contraction. When wood expands or contracts due to changes in humidity or temperature, it can change shape. We've seen guitar panels left, out on the shop bench, cup or twist in an hour or less.
If kept in a weighted flat stack with pressure across the entire face of each panel (no overhanging unsupported edges or ends), your wood will remain perfectly flat for as long as you wish to store it.
Fortunately, if wood cups, twists or warps in any way, which can happen in shipment or just normal handling, it's reasonably easy to make it flat again. All it takes is a bit of moisture, pressure and time. Even very hard species like Ebony are easily reshaped in this manner.
It's a simple matter of using a wet cloth or spray bottle to moisten the wood surfaces. The entire surface should be moistened, not just specific areas. A general rule would be that the thicker or more deformed the wood, the more moisture you will need. But, it is better to start off with less rather than more until you get a feel for it.
When moistened (not soaked), wipe off any excess water with a towel, and flat stack with enough weight on top to press the panels flat.
We place 8" x 24" pieces of 7/16" OSB between each panel to maintain even pressure across the entirety of both faces of each panel. This assures the fastest and most efficient flattening process.
If they are severely misshapen, press them part way, then in a couple days, remoisten, press completely flat and check in a couple days again.
If necessary, repeat the moistening and pressing process. It is then ready to flat stack for storage, or to be stickered for final acclimation to your shop environment for fabrication.
Stickering your wood is important if it has just arrived in your shop from a different location, or if recently moistened for flattening, and you wish to use it right away, rather than store it.
Stickering is a method of using even thickness "sticks" to separate your wood when stacking it. It provides support to hold the wood flat and allows air circulation to acclimate your wood to your shop. 3/4" wide x 8" or 9" long strips of melamine covered pressboard is our choice, but you can rip down any stock so long as it is even thickness.
Make sure to place stickers at the ends and in the middle of the panels, and that the stickers are one above the next to assure proper support for the panels. If panel length changes in the stack, to assure even support, place a piece of plywood across the stack and then continue stacking.
And remember not to leave tonewood in direct sun or near any other heat source, or in a breeze or damp area.
Following these simple steps will help assure your tonewood stays in top condition.