Q: We produce solid oak plank tables using random-width pieces to make up the final width of the panel. As with all panels, we experience shrinking and swelling out in the field. The question arose if we built a panel with all pieces being the same width throughout the panel, would this decrease the shrinking problem? We maintain around 8 percent moisture content.
A: Your problem is that the incoming wood is too wet. When you say "around 8 percent moisture content," I will bet that you mean that you have some pieces that are 9 percent or even wetter. Because the interior environment in most houses and offices during heating season will be about 30 percent RH (or even lower), which will result in 6 percent MC in the wood (even if finished), your 9 percent MC pieces will dry to 6 percent MC. Accompanying this drying will be about 1 percent shrinkage with oak.
If you dry your lumber correctly before making the panels, instead of letting the wood dry in use, you will have virtually no problems in the field.
In response to the rest of your question, the panel made with random-width pieces will behave the same as a panel made with fixed widths.
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