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Showing posts from July, 2018

Foil thoughts

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Starting to do some research into foil shapes. The standard approach is to use NACA0010 / 0012 for the rudder and think about of the NACA six digit series for the daggerboard. Laminar flow sections are faster underwater, but have issues getting the water to flow at higher angle of attacks. As I sail in an often light air venue I may end up building two daggerboards, one nice and forgiving for light air sailing and the other aimed at higher speeds. http://airfoiltools.com/ provides some great comparisons of different sections. After some time spent in here I've pretty much discarded the idea of the laminar flow NACA section and am contemplating an RC sailplane section  EH 0.0/9.0 . A problem I hit pretty quickly was that my girder was build 2mm too thin. This then makes the daggerboard slot too thin! At the time I knew it was slightly too thin (but don't remember thinking as much as 2mm - so I don't think I thought about that properly) but didn't properly think th

Fairing (first pass)

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FarrOut is going to get its hull fair in two stages. The first before applying glass cloth to get the basic shape smooth and the second prior to painting. Fairing is done with West System 407 light filler. If you don't normally wear a mask I'd highly suggest donning one for this stage as the material is very light and tends to puff out off the mixing bowl especially as the additive is a fine dust. I learnt a few tricks during this process. Firstly wet the ply with a wet (neat) epoxy coat before applying the thick mixture as it won't penetrate  the wood very well on it's own, but will chemically bond to the neat mixture you laid as a base. Secondly down strips of the fairing compound first. You can do this pretty roughly as they are easy to sand. Let them cure for a few hours and sand them down (see next tip) Notice that weird board sitting on the boat? That's my next tip! Make yourself a torture board. Mine is probably a little short the pros even b

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