Showing posts with label gaff. Show all posts
Showing posts with label gaff. Show all posts

Saturday, May 17, 2014

Gaff and boom



The next thing was the gaff.  An eyebolt was put through the throat for clipping the throat halyard on.  A metal strap bent into a U-shape and attached to the underside of the eyebolt was used to secure the mainsail’s throat.  The head was laced to the gaff just as the lugsails of the first rig were laced to their yards, using a series of marline hitches.  Photos of these will be on the next post.

I also put on a loop of line (secured with a steel eye strap on the underside of the gaff) where the peak halyard will be clipped.  This method of securing rigging with loops of line going around the spar, rather than using fittings simply screwed into it, was repeated throughout: the shrouds and forestay, the throat halyard block, the mainsheet blocks, the topping lift and the boom vang.

Next came the boom.  The foot of the sail is secured to the boom at the tack with a pin.  A gooseneck screwed to the mast enters the fore end of the boom.  The epoxy-reinforced glooseneck hole in the boom has a mouth with square cross-section to ensure a tight fit and no twisting.  Both are seen in the first photo.  
  
At the clew there is an outhaul line that runs through the aft end of the boom past a sheave and is secured with a clam cleat.  This plus the topping lift, which clips anto a loop of line, are shown in the second photo.
The third photo shows the boom vang.  It starts with a running bowline secured to a wooden cleat, runs through a block tied to the boom, and ties off on a horn cleat.  The boom vang will keep the boom on its goose neck, and stop the boom from lifting when sailing downwind, something that gaff sails are prone to.

Tomorrow if all goes well I will put in halyard and sheet cleats and try out the new running rigging. 

boatbuilder

Sunday, November 17, 2013

More gaff and mast work

Carpentry on the new rig is progressing well.  The gaff jaws (first photo) were put together from two oak boards and four layers of 3/8 inch (9 mm) plywood with epoxy and stainless steel deck screws.  The holes for the parrel line will be drilled later, after fitting the gaff to the mast.

Then I worked on the mast step and partner.  I drilled two horizontal 1/4 inch (6 mm) bolt holes through the partner and bulkhead, and two vertical holes for the bolts that will keep in place the oak board securing the mast in the partner (second photo).  While I was drilling the port side bolt hole the wood cracked.  To deal with the crack and to avoid any more problems I removed 1/4 inch thick pieces from the bottom of the partner and glued plywood there: you can see the plywood layer if you look carefully.


I then put the mast step down on the keel batten with bronze nails, epoxy and stainless steel screws, and secured the partner to the main bulkhead with epoxy and two long lag bolts, with washers and nuts on the other side of the bulkhead.  Then came the time to try out the mast in its place.  As it turns out I had not accounted for the rake of the mast ahead of time (it was hard to do anyway), so the mast could not go all the way in and the oak board going across could not close.  I worked on the partner with the wood rasp, testing the fit several times.  Like all hand work it took a while, but now the mast fits in its partner and step.  Stepping it several times proved to me that it is easily doable by one person.

The last photo shows the new mast and bowsprit.  They still need some hardware and finishing, but I was pleasantly surprised at how straight a mast made from a couple of 2x4s turned out to be.  It is a little awkward and definitely heavier than the previous ones (as it needs to be) but at least it does not need to be vertically dropped through a partner hole, something that would probably hurt my back at my age.  I can shoulder it and walk it into place pretty easily.

I have already cut and shaped the wooden pad eyes for shrouds, and will be working on sails and standing rigging soon.

Until the next post,
boatbuilder

Saturday, November 2, 2013

Mast, step, partner, gaff



I bought SPF (spruce/pine/fir) 16-foot studs for their easy availability and low weight, which is a higher priority than high strength and stiffness, since the mast is stayed.  Low cost is a nice extra.  I chose two that were as straight and knot-free as possible.  Taking them home was a bit of an adventure, involving foam rubber, duct tape, cinch straps, staples and a red rag, but all went well.  Next I glued them together with epoxy.

Next in line was cutting and laminating the bowsprit as described in the previous post (first photo).  I test-fitted the slot over the bow extension.  Then I cut and laminated the bowsprit brace out of a piece of 2x4 and ¼-inch plywood.  There is a 1½ x 2¼ inch rectangular hole on its bottom center, and the bottom is curved to fit the foredeck.  A 1¾ x ¾ inch piece was removed from the rear top of the bowsprit to fit the hole.
 
I also cut and laminated the parts of the mast partner, which may be sturdier than it needs to be but I wanted plenty of strength for bolting to the bulkhead.  The mast step was laminated from a layer of cedar board and two of 3/8 inch plywood (second photo).

Then I set up the table saw outdoors (I needed 34 feet of space for the job, plus who wants to clean sawdust indoors), with my sturdy sawhorses doctored to have supports level with the table saw.  With a friend’s help I trimmed two sides to achieve a 3-inch-square cross-section, then cut off the four corners into an octagon.  All standard procedure I have used before.

The following weekend I hand-planed, tapered and sanded the mast into a smooth cylinder.  As before, I was not intent on perfect roundness or smoothness: this is a home-made mast and a slight hand-hewn look is fine by me.  Here is the new mast along with the old cracked one (third photo).  Exaggerated perspective notwithstanding, you can see how much sturdier the new one is.

The next step was to saw away a 3/8 inch layer from each side of the tip of the gaff (former mainmast) and cut oak pieces that will be glued there to make the jaws just over 3 inches apart.  The four layers of the jaws proper were cut out of 3/8 inch plywood.  The gaff tip was then rounded so it can pivot around the mast with ease.  The various parts are shown in the last photo.



Next steps, hopefully to be completed before the real cold sets in, will be:

  1. Laminate the jaw layers in pairs and screw and glue the entire jaw assembly to the gaff.  The holes for the parrel line will be drilled after careful fitting.
  2. Try out the mast in its step and partner.
  3. Bolt and glue step, partner and bowsprit brace.
  4. Glue and screw oak pad eyes near the mast top.
  5. Finish all with epoxy and varnish.

Then it will be time for the standing rigging, making the sails and fitting the running rigging hardware and lines, if all goes well in plenty of time before the spring.