Bent - Bent knees are formed by plasticizing the wood to make it flexible via boiling, steaming, or microwaving (for small components). While still hot, the wood can be bent into a shape suitable for the location - either on a form or by forcing and securing it directly into the final service location. Steam-bending is a time-honored method for shaping boat frames, but it does weaken the wood slightly, it can leave residual stresses which may cause breakage or spring-back over time, and it is limited in the degree of bend which it can achieve, particularly for thick members. Also, not all species of wood steam bend well.