The Parker Mast-step Repair

by Rick Leir

Parkers in the late 7000's commonly have problems with wood rot in the mast step area. In particular, boats with adjustable side stays have this problem. This article describes how 7951 was repaired.

Rotting occurs when wood is allowed to get wet, so it is important that all wooden structures be painted with something impermeable such as epoxy.

The adjustable side stays run through a block at deck level, then through tubes to the mast step, where blocks turn them forward to a lever tensioning system. The original blocks at the mast step were mounted using hardware which did not spread the load over a very large area of the spruce mast-step, and the paint was chewed away. Water soaked the wood, and over the years the rot spread to an area of 4 by 6 inches. This became apparent on a windy day when the hardware pulled through the wood below the mast step, and noisily pulled through again with every tack!

The repair job was in an inconvenient position. The boat was set upside down in the workshop, with the bow high, to avoid back strain. A rug on the floor saved the knees. A trouble lamp was used to put some light on the work.

A chisel was used to remove all the rotten wood. The resulting hole below the mast-step was an irregular shape, so it was cut some more to make it have straight sides. Mahogany plywood was used to fill the hole, and since the plywood was too thin, several layers were bonded together to get the right thickness. The plywood was cut roughly to shape and oversize, then cut down a bit at a time until it fit the hole.

The epoxy used for glueing cures rapidly, so all parts and materials must be set out and organized ready for quick assembly when the epoxy has been mixed. Epoxy was painted on all exposed wood surfaces, and a filler paste was made from sawdust and epoxy for use in all gaps. It was a warm day, and the epoxy was solid within 15 minutes, with all parts correctly in place and no time to spare! A carpenters clamp was useful to hold parts in place during this work.

The hardware was remounted as before, with the addition of some square aluminum extrusion (2 by 2 by 10 inches) used as a backing plate to spread the load. This protects the wood, and it also anchors the stay tensioning hardware more rigidly. The structure is now considerably stronger than it was when the boat was new, and the weight gain is estimated at less than a pound.

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