Start on The Daggers

Posted by Paul

Using a circular saw with a fence on it, I cut the strips of duflex to 120mm wide, and also strips of 9mm ply. The spine of the daggerboard was changed from a western red cedar block to 3 strips of 13mm duflex but on advise from one of the first builders to build to the new specifications (and with confirmation from Schionning’s) the middle duflex was replaced by 9mm ply because the spine was working out to be too thick to fit inside the profile of the dagger, and the profile (shape) is critical to its hydrodynamic performance, as critical as the rudder shape.

So with the duflex and ply cut to length, I spread some used peel ply along the bench to absorb any glue spills and I spread a layer of sloppy glue along the bottom duflex and the ply and then once glued I stacked them and holding the planks flush with one hand I screwed them to each other through to the bench to set.

The daggerboard at the widest point is about 60mm, the foam sheets are 40mm. So to get to the width needed I can either glue thin (12mm) sheets of foam to either side of the foam sheet to pad it out to the correct width or another method, which is a little more time consuming but less foam consuming is to strip the foam to the width of the daggerboard at the varying points on its profile. So a 2400 mm long, 65mm wide strip (and 40mm deep, the sheet thickness) at the widest point, then 60mm then 50mm and so on as the board tapers forward and back of the spine. You then glue them to each other along the edge you have stripped (i.e. 65mm, 50mm 35mm etc) the gradually narrower strip centred on the slightly wider strip below until you have a rough shape of the dagger made with these blocks ready to shape the hard edges out into a smooth shaped board. This results in less foam being used (or more accurately being turned into foam shavings by the router) and still ending up with a foam daggerboard. The trade off is it takes a little longer (maybe) and uses a little more glue. I figure, time I have and glue, although I am running out, is probably cheaper than the foam so I will use the most economical method.

Tomorrow I will have the foam stripped, I only cut one strip today to see how difficult it would be, it isn’t difficult it is dead easy and then I will glue it back together in the profile I need to match the template, which will be used to make sure that the foam blank is bigger than the template all over so that i can shape it with a router, after I build some kind of rail system for it.

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