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| New bowsprit |
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| Charles:
The inboard end of the bowsprit needs two cheeks which locate either side of the Sampson post, then a pin passes through the cheeks and the post to secure it in place. The cheeks are made from lignum vitae - not necessarily the best possible timber for the job, but plenty good enough and I happen to have some in a suitable size - planned and bandsawed to size, then a plywood disc turned on the lathe is used as a guide for the router to round over the ends. Next, the other end is cut and chamfered on the band saw, and finally, they are clamped back to pack and the hole for the pin is bored. Nex they are carefully aligned on the bowsprit and glued on, one at a time. Glue alone would probably be enough, but for piece of mind I want to put some bolts through, however, i don't want the bolt heads visible. So some 12mm 316 bar was parted off to give two 120mm lengths, each end of which was chamfered, then drilled tapped M8. Next, the fixing positions were marked and 25mm counterbores cut to a depth of about 12mm, then the through hole was drilled, the 12mm bars driven in and button head screws and penny washers screwed into each end. Some offcuts from the same board where chucked up in the 4-jawand turned down to just under the counterbore size, these were bonded in with 5-minute epoxy, once cured they were trimmed with the pull saw and planed flush. |
| seadog:
Nice job Charles and a nice classic boat. I remember seeing a mast being fabricated at Shepards Wharf about 20 years ago. I was amazed to see that it was fabricated from glued strip and was hollow. It was around 18" diameter at the step. Graham |
| Charles:
Graham, Thanks for looking. I did consider making this spar hollow, but the effort required relative to the minimal saving in weight, particularly at deck level didn't seem worth it here. I've also heard of people using cedar cores to reduce the weight. The outboard end of the spar carries a fitting called a cranse iron, mine is fabricated from mild steel & galvanised - not by me, this one came with the boat. Turned another plywood disc on the lathe, then used the router with a top guided trim bit to remove most of the material, finished off with the pull saw and a chisel when the router ran out of depth. end grain at both ends was coated with epoxy, this makes the timber a bit harder in the areas that bear the load as well as keeping the water out of the end grain. Next, I needed to make a small flat for the end plate of the axel to sit on, so I made a 20mm bushing to fit in a hole saw mandrel, then used the hole saw to cut an outline around the axel hole, then a chisel to remove the material inside the outline - about 20 minutes of tool making for 20 seconds of drilling.... That's the woodwork finished, so first coat of varnish can go on. Almost the last bit is the end plates for the axle, just big washers essentially, cut from some scrap stainless sheet with a hole saw, except that the holes saw and the pilot drill don't seem to want to run concentrically tonight, so took the pilot bit out, cut some blank discs, then mounted each disc in the lathe to make the hole. |
| vtsteam:
Nice job on your new bowsprit, and very nice boat, too. :beer: |
| Charles:
Remaining steps on the bowsprit - apply varnish, I use Sikkens Cetol, not quite a yacht finish, but only needs four coats, last a couple of years and is really easy to prep & reapply. Then assemble all of the metalwork, make up a traveller from some D12 hollow braid Dyneema. A traditional traveller would be a galvanised steel ring, wrapped in leather, these are expensive to buy, or a faff to make (150mm diameter hoop in 12mm bar). So I thought I would try a modern alternative, seems to work well on a dry run, we will see how it fairs at sea next weekend... Traveller line is just 8mm braid on braid, spliced into the shackle at both ends and threaded through the cleat at the inboard end so it can't get lost. Onto the boat, shrouds and bobstay made up from more D12. Bobstay fitting is the final piece of new metalwork, hewn from solid 316 on the lathe. Really should have radiused the corners, but ran out of time/enthusiasm... Will take it off at the end of the season and finish it properly. |
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