Hadron H1 Sailboat

I’m working around the clock to finish my second sailboat before thanksgiving.

The Lowrider has been indispensable again.

This is the intended design: The Hadron H1 singlehander dinghy by Keith Callaghan

albeit mine should have an asymmetric spinnaker in front.

  1. Cutting out the plywood - 6mm okoume for planks…the rest varies from 4mm to 12mm.

note the puzzle joints. i am hoping the overlay of planks will be mitigate any risk of structural imperfections. plus i reinforced the most vulnerable joins with fiberglass.

  1. I flow-coated (three layers of wet on wet epoxy) everything as much as i could before beginning the build. A lot easier to do this ahead of time flat and off the jig.

For this build I went with US Composites “Thin Epoxy” and their Aerosil-Cabosil and Fairing fillers. They are cheaper than West System without all the marketing. Their pump system is far superior. I will say West System is a mine of information on techniques and best procedures.

  1. Bending the planks over the mdf jig. centerboard box already fitted into jig. it might have been easier had i not flow-coated the first two planks…anyway it got done with a lot of clamps and the occasional temp screw.

  1. Cedar core centerboard and rudder: used lowrider to cut contour pieces to assist when planing.

Here applying three layers of carbon - unidirectional, twill X 2 and a final thin blanket of fiberglass.

Wood boat building regrettably comes with a lot of bad waste.

  1. Filled any gaps with adhesive filler, applied blanket of fiberglass across bottom planks and tape over all seams.

  1. Faired in tape seams and applied another three coats of epoxy that absorbs into filler and any unfilled bubbles in tape.

  1. Primed 2 coats. Waiting on a proprietary filler that pairs with Interlux for final ‘final’ fairing which I will do at the end. Boat color will be red.

  1. Off jig!

  1. Taping interior seams and fairing this week…then interior buildout.



I had to go look at the website. I was a bit surprised by the low transom with the holes in it.

I’ve seen several competitive sailing dingy designs with that feature. My impression is that it cuts down drag (both wind and water), removes weight, and makes the whole boat “self bailing” if water does get in.


And on bigger boats than dingies…

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Yeah. I had to do some reading. It looks pretty common on race boats. I’ve just never seen it.

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That is beautiful.