boatnut
04-23-2003, 12:08 PM
I'm reading lots of information about repowering Donzi classics, classic hull design, props, etc.
This is all of great interest as we are considering repowering a '69 18. What I haven't seen any discussion on (maybe there has been some as I am fairly new to the forum) is the subject of truing the bottom of these classics when you want ultimate performance. I have checked 3 or 4 Donzis of various ages, and (using a staight edge on only a short section forward of the transom) have seen varying amounts of hook and once even a little rocker on these boats. My experience (admittantly on non-Donzi hulls) has been that if you really want the ultimate in performance you turn the boat over and "true" the bottom. Using a large (4+ feet) straight edge, you fill/grind/sand all hook out of the hull and strive for a staight running surface. You then can control this running surface with the various afterplane products on the market knowing the bottom is true to start with. My question, is this worthwhile for ultimate 18 performance?
I'm not sure what Donze strives for (in the way of hook/rocker) but I assume some slight hook is desired?? I do know that this will change over time depending on how long the hull is allowed to originally cure in the mold (sometimes not enough in a production envirnonment) and even is effected by incorrect trailer bunks etc. Your comments would be appreciated.
This is all of great interest as we are considering repowering a '69 18. What I haven't seen any discussion on (maybe there has been some as I am fairly new to the forum) is the subject of truing the bottom of these classics when you want ultimate performance. I have checked 3 or 4 Donzis of various ages, and (using a staight edge on only a short section forward of the transom) have seen varying amounts of hook and once even a little rocker on these boats. My experience (admittantly on non-Donzi hulls) has been that if you really want the ultimate in performance you turn the boat over and "true" the bottom. Using a large (4+ feet) straight edge, you fill/grind/sand all hook out of the hull and strive for a staight running surface. You then can control this running surface with the various afterplane products on the market knowing the bottom is true to start with. My question, is this worthwhile for ultimate 18 performance?
I'm not sure what Donze strives for (in the way of hook/rocker) but I assume some slight hook is desired?? I do know that this will change over time depending on how long the hull is allowed to originally cure in the mold (sometimes not enough in a production envirnonment) and even is effected by incorrect trailer bunks etc. Your comments would be appreciated.