Mike, Thanks very much for the comments! I will pass them along. Here are a couple of thoughts: >The O-ring grove sounds like a sound approach to me. I also like changing >the lids to the same material as the tanks because it eliminates the >different thermal expansion between the tank and the lid. Yes! >Doubling the number of fasteners is probably overkill and it will >make access more >difficult, It is already pretty difficult if it involves pulling the engine! ;-) >but I would do because the lid is going to be much stiffer than >the tank, so you could still have the tank flexing and pulling away from the >lid. My main concern is the tapped aluminum threads. Aluminum tends to gall >and Aluminum threads are typically only adequate for a very small number of >cycles. As a rule Aluminum threads are not allowed in the Aerospace >industry. I would ask Q-West to install helical inserts in the holes. As I understand it, the bolts will not ever be removed, but will be threaded from the inside of the plate and locked. The threads sticking through will be used as studs, and nuts will be applied to the outside. These nuts will be taken off and replaced as the plates are removed and reinstalled. >Sometime, when you get time, I would like to hear you lessons learned from >your experience with Michael Kasten and building your boat overseas. Quick answers: >Are you happy with Michael's performance? Very happy. >What would you do differently the second time? I guess that I would alter my expectations regarding time to build. Most yards have no experience estimating the building of a tiny, complex boat. They add up the amount of welding, the amount of wiring, etc, but they don't fully realize the extra difficulty of working in confined spaces, and the way it limits the number of workers who can be effectively employed. So far, the key is to choose a designer who can visualize the details of the boat and express them well on paper, and a builder who will execute properly. No matter how detailed the designer's plans and calculations, the builder will wind up making a huge number of decisions on the shop floor, so you need somebody who will make the right choices to get the boat you intended. Michael and Q-West have done an outstanding job. I don't think my proximity to the yard made much (if any) impact on the final product, and I am quite sure than none of the major problems encountered so far would have been avoided if the boat had been built closer to home, so I feel pretty good about building in New Zealand. >How well has the boats performance matched the predicted performance? So far, it has matched weight, handling and speed predictions exactly. I hope to verify economy predictions eventually, but that may take a real passage. Livability, reliability and maintainability are other things that can only be assessed after a bit of time. Ruggedness and watertight integrity I hope never to have to assess... Cheers, Charles -- Charles Vollum http://xsw.com/boojum - trailerable ocean-going tugboat