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Introduction

I hope this site is of value and contains information. I will record my ramblings regarding sailing adventures, my boat projects and anything else that might interest people attracted to a site about Wharram catamarans.

Please visit again for updates and do leave your comments.


Friday 10 February 2017

Spinnaker Spun

This is the final spinnaker construction post. There will be something on how it flies, but we'll wait for the weather.

The final tasks were sewing on foot and leech tapes, and the luff tape. The foot and leech are finished with folded strips of ripstop nylon. I cut 20 mm ribbons of cloth from the scraps after cutting the panels. The ribbons were taped on the inside of the marked out lines and cut with the soldering iron. I then used the tape to baste the ribbons on one edge of the sail and then folded the ribbons around and onto the other side of the sail.

This looks difficult, but it worked out well. 

Once the ribbon was tapped in place, it was easy to zig-zag stitch over the ribbons with the machine.

The next task was the luff tape. This is made from a 50mm Dacron strip. This was folded and creased over the edge of a table (see Sailrite Spinnaker videos) then tapped on and sewn. Easy. You can see the luff tape in the picture below.

The luff tape also has a 1.5mm dyneema luff cord inside with small loops of webbing sewn at each end to allow the cord to be tied off as follows:


The final job was to make up the corners. I used a similar construction to that shown in the Sailrite videos. I found the lengths of my panels were not as consistent as I'd hoped, but I was able to cover up and compensate using the corner patches.

I used three colours of webbing in the corners so as to mark the head, tack and clew. 50mm stainless rings were sewn in.


Pudding and eating comes to mind at this stage. If it's a disaster, will I tell you all ? We'll have to wait and see. Only another few weeks until the boat goes back in after the winter. Would I build another sail? Well probably as with experience, another would not be too much work. It's been enjoyable.

For information the sail is: Luff: 6.2m, Leach 5.8m, Foot 4.6m Total area - 21.5 sq m.

Monday 6 February 2017

Bright Ideas

On and off, I've been working on my navigation lights project for some time. I've created a few 3D model clips for the Guardian Adventure Lights I plan to base my design on. I need to replicate the clip so that the light will fit onto the shield that will create the 112.5 degree light arc.

After the first print, I realised I had simple modelled it to the wrong size. With this corrected, I printed a new clip. After a little fettling I tried it with the light and it fitted perfectly. I like this 3D printing thing.

I then started on a basic light shield to ensure the light is only seen over the correct arc. I needed a couple of goes at this to realise just how much light can be seen even from the tip of the light. You can see the evolution of the basic design here:
It's also worth noting the arc of light you can on the table top. This is caused by the lensing of the light's cover. It measures almost exactly 112.5 degrees.

The next thing to think about is where on the Tiki 21 these lights should be mounted and how. My first thought was to mount on the beam ends. From here it seems the lights would be prominent and perhaps easily mounted. There are a few problems with this position:
  • Nav lights will often be used coming into a port (in the dark!). For a Tiki 21, this is probably not according to "Plan A"! When you arrive at the end on a long day (Plan B), in the dark, the last thing you want it to break out the dock lines and find the beam ends cluttered with nav lights.
  • The beam ends are often close to and at the height of the dock. The light are vulnerable.
  • Moving the lights to the front beam would help, but in the dark and under less than ideal conditions, moving forward to position the lights is not good. 
  • Mounting over the water, means they will eventually get dropped in the drink.
The more I think about position, the more the beam ends are wrong. Next, the gunnels? A small threaded nut, recessed into the wood and a thumb screw on the light? Complicated I think.

Mounted on the top of the mast beam, just back from the cleat seems good. It also allows a better shape for the overall light housing. This is the approach I'm currently following. I've started on a full housing shape and it's looking good. See below and watch this space.