December 2015

We have been sailing the Duo 480 Jigsaw for a while now, although not over the southern hemisphere winter.
It has taken a while to get the hang of the biplane rig, but finally we are getting it right. the angle of sheeting , and the angle between the two sails is critical for good performance. Previously we had been getting reasonable speeds on the wind , but not on a reach, but finally, admittedly in a nice breeze, we have been getting good results on a reach, too.
Last season we did not crack 10 knots, and nor did we at the start of this season, but all of a sudden recently we have done 11 and nearly 12 knots, not too bad for a 4.8 metre cruising boat.It is difficult to take photos when you are sailing fast, for us, at least. I hope to invest in some sort of wearable vid cam (Gopro etc) with which it should be possible to get a bit of reasonable footage to show how the boat sails when it is starting to move well.

Feb 2015

Details of my bow net. I almost was not going to bother with it but I am glad now I did because without it, it would be impossible to get on board the boat from the front, even at a beach.

 The small tubes mounted on the inner hull sides , get notched out at about 150 mm spacing, and a fibreglass rod about 4mm diameter is inserted. The lashing from the bow net goes round the rod, back out again and onto the next notch and so on. I made the profile of the net myself by taking a pattern of the bow net space on the boat, minus 50mm all round. After taking it away from the boat I put small nails round those lines and loosely stretched out the netting. Then I put 6mm diameter glass rod round the edge line and tied the netting round that with 2 rows of knotting , all while still stretched on the pattern. Then I trimmed the excess of with a hot knife . Leaving it all attached to the pattern boat I took it back up to the boat and with adjustable saw tables raised it up into position. Then I temporarily attached it with plastic cable ties, pulled the pattern piece out from underneath, and tied off the whole thing to the boat as per the photos. I should have taken a photo while it was still on the frame but forgot.

Testing out the furling and sheeting of the sails on the grass at home. Everything works. I have subsequently made a mast raising jig which keeps the mast vertical whilst preparing to lower it into place.

A word about the sails: There are several options for sails in the plans, depending how technical you want to get, and it is even possible to use large windsurf sails. In the end I decided to go with the system similar to that used by Hobie in their Bravo catamaran and AI outriggers. This is one of the options Bernd suggests with the boat.

The long angled battens are 7 mm fibreglass rod and they are flexible enough that they bend round the mast when the sail is furled. The masts turn in the mast holders (see earlier photos of mast base) and the furling and unfurling takes just a few seconds, per side. I also wanted to try a boomless set up and so I had to supply to the sailmaker  a lot of measurements of the boat , masts, and various heights and spacings so that the clew of the sails would finish up with an even pull , both downwards and outwards when the sails are sheeted in. Worked out well for up wind sailing  but I am experimenting with poling out the leeward sail when reaching to maintain better sail shape. 

  I made a plywood rear mast holder to go with the factory built front holder on the trailer, installed an outboard motor bracket on the boat. I had hoped to avoid having a motor but in the end decided it was worth having one. The 3.6 hp motor provides more than adequate power and the tilting bracket puts the prop plenty deep enough.

Launch day (finally) The boat floats well above its water line till Greg and I hop on both at the stern.( Must go back to the gym soon) We spend a few hours happily coming to terms with the intricacies of the biplane rig in light winds, and then sail back to Westpark Marina and pack up just as easily as the launching itself. I think soon I will be able to manage launching on my own. Of course sailing single handed is easy.

Subsequent sailing days, mostly very light winds. One day we had some good wind for a while going upwind at 9.8 knots, which was the best speed. The boat gets up to 7 or 8 knots very easy even in quite light wind but it takes a bit more wind to really get going. Winds were mostly light on our sailing days , because we were still learning how to handle the boat. The good looking young man in the yellow life jacket is Rodney of KD650 fame.

A short video of Duo 480 Jigsaw:
https://youtu.be/yfKaTrBpgmU

Index of materials (to follow)

Epoxy

Glass cloth

Windows and hatches

paint

masts and spars

sails

sheeting hardware

trailer

December 2014

Non skid applied. I used Hempel system (as well as their paint on the whole job) . Mask off area desired, apply paint, sprinkle non skid on , allow to dry, vacuum of anything loose, apply top coat . It seemed to be a little bit too abrasive at first but once in use I was glad of it and it may have “mellowed” a bit also. More detail of the rudder system: Not shown is the 2 wraps of shock cord that hold the blade in place yet allow the blade to kick up if an obstacle is hit. May be visible in later sailing photos. Here though is visible the flat sections I put on to the blade to keep it straight in the rudder box. These flats are just filled epoxy which I achieved by masking off with pvc tape, then double sided foam tape, then more pvc tape. Then fill with thickened epoxy and jam the whole assembly inside a plastic lined tray which has the thickness of my rudder box.

Also more paint job photos plus my trailer which was custom made. I chose not to use rollers on the trailer because of point loading, so the trailer maker fabricated pivoting mounting brackets to which I added my own pads (bunks), covered with 2 layers of marine carpet. The boat goes on and off the pads quite easily, especially with a splash of water onto the pads).

Jan 2015

Close up of the trailer with pads on, boat now on the trailer (with a little help from my friends).

 I should have been sailing before Christmas but my sails , which were made in San Diego California, got lost in transit, and did not finally arrive till February 2015.

November 2014

Final topcoat painted with contrasting colour scheme and waterline picked out. Windows fitted.

October 2014

Hatch is finished, cabin top is epoxy primer coated. View of my masts which are a little more substantial than they appear in the photos (6.3 m long) ,also the bearing system which are basically nylon sleeves machined to fit my mast holder tubes, and glued in place on the masts to suit the base and where the masts exit the cabin top. The mast holders have a base inside them which I fabricated from some of the composite plate as I used for my mainsheet attachments (November 2013 photos)

September 2014

Cross section of  rudder blade. The open top and bottom get a wood capping and are shaped as per the plan drawings and then glassed and faired. Hatch way washboards epoxy coated.

 Rudderbox and tiller assembly. I have gone for the open back cassette system, and I got my pintles and gudgeons fabricated in heavy 316 SS to match the thickness of my rudder box

August 2014

Construction of rudder blade, which is basically a tortured plywood approach with some CF inside (as per the plans). The triangle shaped pieces sitting inside were just to help hold the shape firm in the jig while the first stage  (gluing the 2 leading edges together ) was done. I had to modify the jig, which was borrowed from another builder, by putting spacer strips along the upper section to close the jig up a bit. The correct angle is 18 degrees each side- as per photo.

 I did a test section first, and also experimented with the trailing edge. Here I left it square but when I glassed it I inserted filled epoxy in the gap where the two wet layers of glass overlap and clamped  this whole trailing edge with pvc tape covered battens. When cured I trimmed it with a straight edge and fine blade using my handheld circular saw. This worked well so I used the same approach when I did the real blade, with the result that the trailing edge of the rudder is quite strong.

April 2014

Extra glass tape at edges of cabin top, glassing the cabin top and cockpit, test run of the accommodation inside the boat