By Kristin Stewart
If you are unfamiliar with the construction of a bird's mouth mast you may wonder how these pieces of spruce...
become this this.
Although I had seen a cross section of such a mast, I had never seen the construction from start to finish. The completed mast for the Danish Spidsgatter Smil would be 40 feet tall with a taper from 5" at the base to 2"at the head of the mast.
 |
| James did the math to determine the taper of the staves from the top of the mast to the base. |
 |
| Measurement and calculations of stations and tapers to shape the staves |
 |
| The stations on the strongback are covered in plastic so that the glued staves do not stick |
 |
| This is the top end of the mast, the circumference will be planed down to a 2" radius. |
 |
| This is the first dry fit using hose clamps assuring tight connections. |
 |
| Shawn is putting protective plastic down on staves #5 and 8#. So that when #1-4 are glued together they only stick together forming one half of the whole mast. |
 |
The staves are glued together with a paste of epoxy and wood flour.
The stave on the top of the picture shows a scarf joint.
16-18' boards were joined to make them 40' in total |
 |
| James walks to the end to turn glued stave #3 to abutt with #2. |
 |
| Hose clamps are added to the smaller end first |
 |
| As Shawn tightens the clamps down the line James watches for extra epoxy to squeeze between the staves. |
 |
| the second half is glued up and curing |
 |
| Andy planing an octagonal brace |
|
The two halves lay side by side. They are ready for wires, bracing and the addition of the mast step piece.
|
 |
| The octagonal brace is fit for structure at the position of the spreaders. |
 |
| The octagonal piece is transformed into a crown brace on the bandsaw |
 |
| A crown brace distributes the stress load. |
 |
| Mast light wires are strung through the inside before the final glue up of the two sides. |
 |
| The white tub protected the wires from being glued together. After the glue was cured the wires were pulled out the side of the mast, through a hole, about a foot up from the bottom. |
 |
Piles of shavings from the initial rounding of the mast. Next, concave pieces of styrofoam and sand paper
were used to sand it even and round. |
 |
| Purpleheart wood 'hounds' where the mast bands set for rigging and sail track mounts |
 |
| The mast gets its top coats of varnish. |
