I have used sapele on the interior of a gun case and some boat parts and had no issues.? In general, I think it is known as a fairly stable and workable wood.?? ?Moisture in your material might be one problem.? Another could be the log that it was sawn from.? A tree (any tree) that grows less than vertical will have compression wood on the underside and extension wood on the upper side.? Ripping boards will expose this defect.? Care in drying will not prevent it.? Naturally, the more off vertical the growth, the greater the defect.? Its a matter of degrees (- ; )? Worst case, boards sawn from branches will also carry this defect and should not be used for furniture or fine joinery.?
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Probably the best way to avoid this material is to by from reputable suppliers that honor return sales.? No one wants to pay for a hardwood floor twice.
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Jonathan Smith