Hi Rod. I built an Eco7.5. My rudders were laminated wood. But my dagger board used Bernd¡¯s V system. I had problem because I could only get 6mm plywood instead of recommended 4mm.? Bernd¡¯s advice to me was to use a router for 1-2 mm along the whole ?length of the inside faces (spaced about 5 cms apart.) This again was straining the ply a bit so I ended up repeating the router groves as deep as 3mm. It worked out fine. I used some slightly thickened epoxy on the inside of all the grooves before closing it all up.? I hope you get some success?with this method. ? Best regards Chris Gent.? On Sat, 18 Mar 2023 at 23.01 Rod McLaren <nkosuohene@...> wrote: Recently I made my first attempt to build the rudder blades for my ECO 6, and met with a big failure. Advice, comments, suggestions are invited before I make my second attempt. The photos show what happened. The ?Meranti is very stiff, almost brittle.? It appears to me I put too much epoxy mix in the V. The building plan diagram for the ECO 6 specifies filling to ?a line drawn at 13mm from the leading edge. The directions call for the line to be drawn at 15mm. I was aiming for the 13mm line but I expect I added too much - it was difficult to tell. It was also difficult to keep two pieces of plywood so that they meet only on the corners - i expect the join looked more like the one in the left of my rough drawing. I am not sure how significant that might be. If that is critical, perhaps someone might suggest how to achieve that. |