Balsa wood is often the wood of choice when a woodworking project involves curves that require the wood to be bent. Special methods for bending balsa wood may not be necessary if the curve is a gentle one and the radius is large; the wood may conform easily. For more complex or tighter curves, however, use some specific practices to ensure that the balsa wood will bend without breaking or splitting.
Select A-grain balsa wood for more difficult curves and bends. A-grain wood is more flexible than B or C-grain pieces, which are more likely to split when bent. When possible, bend the wood so that the grain of the wood runs with the longest side of the piece.
Submerge the balsa wood in a container filled with a mixture of equal parts warm water and ammonia. Allow it so soak for at least an hour—longer for thicker pieces. This solution breaks down the balsa at the cellular level and is thus especially effective in making the balsa wood more flexible.
Place the wood against the curved form or template and shape it to fit. Tape the wood down to hold it in place and allow it to dry thoroughly. Do not attempt to glue the wood while it is wet. Depending on temperatures and humidity, this may take two to three days or more.
Remove the tape from the wood when it is dry. The wood will spring back away from the form or template a little, but that is normal.
Spread the glue on the wood with the brush and press the wood back to fit the form or template. Secure it in place with tape again and remove the tape after the amount of drying time recommended by the glue manufacturer.
- A-grain balsa wood
- Warm water
- Masking tape
- PVA (white glue) or aliphatic resin (yellow glue)
- Glue brush