Tuesday 28 October 2014

Extending the Mizzen Mast




During the West Coast Rally in May 2014 and with only a couple of days to go before I planned to tow Tra Bhui out to Denmark for the "Viking Cruise"we tried our new Jib and Mizzen sails for the first time.

Ever since we purchased Tra Bhui the boom for the Mizzen sail had fouled the top of the outboard when the outboard was raised, Our new mizzen sail although the same size as the original one appeared to have a longer Luff as getting tension on it was virtually impossible given the available mast length. The easy solution would have been to simply lower the boom but as it was already striking the outboard, extending the mizzen mast was the only practical solution.

Once we were back home from the West Coast Rally, I decided to add 24" to the mizzen which would also allow me to raise the Mizzen boom approx 9"on the mast thus allowing the boom to clear the outboard. The additional length of mast would be used to accommodate a Red Ensign flag as we would be required to fly an Ensign when we were sailing outside British waters

I planned to form the new mast extension with a slightly square profile at the top rather than taper it into a minimal thickness. This would allow me to mount a HF active antenna at a future date should I ever install NAVTEX or a HF radio on board. 

The extension was formed using a old bit of Scott's pine that I had lying around the workshop. It was not the best piece of timber due to a number of knots, but by selecting where the cuts would be made I managed to get a knot free bit to use.

This was a rush project as it needed to be completed in a morning to allow time for it to be painted / varnished and it to dry (the afternoon) before Tra Bhui was packed for the Viking Cruise.

The photos below show how the mast extension was quickly put together and the mizzen boom raised to it's new position.  Crude but effective!

Cutting back mast to form Scarf Joint

Preparing scrap piece of timber to extend mast

Glue and clamp new and old 

Rough plane of new mast top

Shaping mast top

Shaping mast top

Extended mast
Mizzen boom mocked up in new position

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