Good day all My mission today is all about avoiding the bow in the top stringer of the boat - especially when the fuselage is being substantially widened (and the wide section moved aft).
a) I have noted the technique of deliberately building the sides with a known opposite bow - thus resulting in a straight top stringer after the sides are pulled into the boat shape. Sounds great but complicated for me as I would have to establish my own offset bow. b) Riley Collins pointed out that some KR's were constructed with vertical (or near vertical) sides, thus eliminating the problem. Is this a popular approach? It does not distract from the appearance - maybe increases the frontal area a bit - but certainly easier to build - Sounds like my style. c) I was impressed with the technique used by Eduardo in Argentina - he starts construction by building the top longerons into a horizontal crutch flat on the bench. The balance of the boat (lower fuselage) is then constructed (inverted) by adding formers and more stringers. The positive is that the formers can be rounded, giving a pleasing shape to the boat - also we have a nice straight datum line for all future measurements, incidence, thrust line, etc. He completes the boat using urethane foam fill between the woodwork with an epoxy /cloth skin inside and out - a meaningful cost reduction with no plywood, NO scarf joints. This would be the way for me, except that I am not convinced that this structure is equally strong - the only stringers that are continuous runs from the firewall to the stern post are the top stringers - all the others run in sections between the fuselage formers (presumably to keep the inside flush for glassing). I can see that an epoxy /glass skin is an acceptable alternative for the plywood skin, but what is carrying the load that would normally be transmitted by the two lower longerons on a standard KR boat? I would have preferred at least the keel to be continuous (and a bit wider). I initially thought that Eduardo had pioneered this technique (on a KR), but I have since seen pictures (97 or 98 KR gathering) that Dr. Dean Collette was using exactly the same approach. Is Dr Collet still around? - how far is this bird now? My interest here is to establish if anyone has run the numbers on this fuselage structure - is it OK? Steve Askies"at"microlink.zm
