Hello, first post here ive been lurking around the forums for a while now and has a been great tool with all the information available. I have always wanted a dyne since i saw one at the ski broncs show probably in the early 90's. At the time my dad had a bayliner with force 125 outboard so when i saw a dyne with twin 250's hanging off the back i was amazed. So finally last fall i purchased a 1969 18 with a good running 1979 johnson 235 on the back. I knew that it had a good chance the core was soft, (only cause i read it on hydrodyners) but for what i gave i feel it was worth it. The next day we got it in the water, and wow what a fun boat really moved and seemed solid. I figured i would do some barefooting behind it. So i go to do a deepwater and pull rips pylon out of the floor. So basically what was suspected was now confirmed. Anyway i did use some bondo glass and mat to reattach the pylon and proceed to ski and foot behind it the rest of the season. When i repaired the pylon i drilled some holes into the core and all i found was mush. So i decided over the winter i would tear into her. Well winter is over and im just now starting to get going on it. Im makimg this thread to 1. Document my progress and 2. Hopefully receive comments and feedback from you guys on the process.
So basically what i want to do is functional restoration. Not a show quality restoration as i plan to use this for skiing mostly. This boat has been painted and still has a nice finish so im looking to stick with that and not have to repaint. I also do not want to remove the deck. The transom seems solid and im sure it has been replaced at least once. But i havent thoroughly investagated it. So far i have only demoed the floor. As far as supporting the hull i have it set on a wood framed cart and used spray foam. Im thinking this should contour to the hull and support it well. Though i havent seen anyone else do it. What do you guys think?
If you have removed the core you have a shell left and it will flex. Make sure it is supported well with no hooks etc. before the new core goes in.
Foam support is new to me but if it was straight when you did it it will probably work if it won't flex. I have heard the early hulls had no floor, just a thick core of balsa 2X4 type material laid lengthwise in the hull. Modern balsa core is end grain 2x4 blocks bonded to a "scrim" cloth. The original style balsa allowed moisture to "wick" the length of the hull which promoted rot. The scrim type insulated the blocks so if one got wet, the rest were protected. If I were doing an early hull I would convert to a 3/4" balsa scrim and build a floor like the later hulls have over it.
Check out my thread "1972 Keel Up Restoration". I have already done the core and have lots of pics that should help.
The spar foam support. Seems like it will work well but i wont have a visual of the bottom. I had the foam left over from a job so it didnt cost me anything wich is a.factor in this build. I left the core intact before i did it. The core seems to be made of a double layer 1'x2' balsa that is all mush now, then some 1"x3" and 1x4 that are still intact. So will a single layer af endgrain balsa be sufficient for the new core or should i go thicker. Tj i have read through your thread a couple times, very impressive work.