Here are a couple of photos of my junk rigged dinghy:
The dinghy was originally lug rigged with a rudder that only just touched the water. Even with a new rudder the lug rig was stressful to sail due to the heavy yard and boom swinging around, and the flat-cut lug sail struggled to go upwind.
The junk rig makes the dinghy very easy and relaxed to sail. If you see a gust coming you can reef instantly. Gybes and tacks are easy. The cambered sail goes upwind very nicely. With its large area high-up and ability to put that area across the boat it goes off the wind very well.
I designed the rig based on articles by Arne Kverneland on the Junk Rigged Association website. The mast is an old aluminium windsurfer mast (very lightweight but a bit flexible); yard and batterns are aluminium tube. Sail is made from lightweight polyester – basically tent fabric – with battern pockets from some green acrylic canvas that I had from another project. The sail construction was easy but fiddly – there are a lot of parts to join together.
The sail is rather long from front to back giving a low aspect ratio. This was forced by the existing mast position in the boat – far forwards – and the centreboard position which is a bit far aft. Aesthetically the sail would be better with an extra panel to make it taller. However in practice she sails beautifully!
Martin's Blog 
Impressive looking junk sail. If you don’t mind? How big is your boat, how tall was your aluminum mast, and how tall do you feel you should have gone with a mast supporting the taller sail you think you could hoist above your dinghy?
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I’m not sure exactly how tall the mast is – the boat is elsewhere at the moment. I’d guess around 15′ or 5m. The boat is 11′ long – 11.3m.
Given lots of time I’d add another panel to the existing sail. The mast is plenty tall enough for this although the performance is fine without it. The limiting factor is the strength of the mast. Clearly a windsurfer mast wasn’t designed for a heavy dinghy. If I tried hiking out in a strong breeze I suspect the mast would buckle.
However, for my purposes this is fine – I would rather the mast failed than the boat capsized given I’m carrying small children in it. The light weight of the mast helps stability too.
If / when the mast fails I’ll replace it with something a bit stronger – maybe a Laser or Topper mast.
More details on the boat here: https://mwbrown.org/2019/05/17/owl-my-current-junk-rigged-boat
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Good!
Dare I suggest you add Hong Kong parrels on the three lowest panels. They whil remove the diagonal creases in the panels and allow them to inflate properly…
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There is a Throat Hauling Parrel (as per your article) that takes the creases out. In these pics the boat was being sailed by someone else (hence I could take the pictures!) and the extra line was too much hassle. There are some pictures on this page showing the effect of the THP: https://mwbrown.org/2019/05/17/owl-my-current-junk-rigged-boat/
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As an amateur programmer and boat lover, this was a real treat and I hope to do something similar when I am able. Cheers from southend on Sea.
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