The Naiad Voyages

Mark Austen

2021.07.04 - Mainsheet Blocks IV

Over the past few days I've continued the work on the new mainsheet blocks.

Once the glue holding the cheeks and spacers together had dried, the cramps were removed and any excess glue squeeze-out removed with a sharp chisel.

The excess material was removed over at the bandsaw and sanded smooth using the belt sander.

At this point the shells are shaped in one direction and need to be shaped in the other.

This is a drawing of the block that I made using my cad software and then printed it out full-sized.

One side of the drawing was cut out to give a template that could be held up to the block to see where the wood needed to be removed.

It wasn't easy for me to achieve as this is the first time I've done this, but here is one of the shells partially shaped.

And again with more wood removed to give a smooth shape.

A groove around the shell was made using various round files and it was at this point that I realised that I had drilled the hole for the pin in the wrong place. It was too close to the top of the black and with the sheave fitted the rope would not pass through the block.

Fortunately I have many Ash arrow shafts around in the workshop. One of these was turned down to 8mm, the smallest I could go using the dowel maker I have, so the holes in the shells were widened to 8mm and then plugged with pieces of the arrow shaft. Once the glue had dried, the plugs were trimmed to length and sanded flush with the shell both inside and out.

The pin holes were then re-drilled in the correct position.

Here the second shell has been shaped but not yet had the groove cut, however, as soon as that was done and both shells sanded with 240 grid sandpaper and they were submerged in Boiled Linseed Oil.

The shells float in the oils so a lead weight was carefully placed on top of the shells to keep them completely submerged. The lid was put on the pot and the whole thing put aside out of the way where the shells will soak for a week. This will allow the oil to penetrate deeply into the pores of the Ash. After a week the shells will be removed from the oil, drained, the excess oil wiped off and they will be hung up in the workshop for another week to allow the oil to dry.

Once the oil has dried several coats of varnish will be applied before the sheaves are pinned in place and the strops added to complete the blocks.

But right now, it's time for a cup of tea.