I think if I did a transom I would build much thicker skins with minimum core thickness and a water proof dense core.
You can not overbuild - just underbuild. Once you get all the wood out and have a shell the fun begins. Put a thicker transom in than original - it does not matter if you go my route with composits or plywood to save money. I do not understand your comment about minimum core thickness. Put the transom in and then the core up against it. What really matters is how you transfer transom loads to the cored hull and sides of the boat. That takes multiple layers of strong glass - each layer longer than the last. The stringers also have to be glassed to the transom with multiple layers of glass and the stringers have to be glassed to the core. It is all about spreading stress over the maximum area possible.
Don't forget we are talking about an I/O. The transom can't be thicker. Let's assume I used a 1/2 inch core and the rest glass.
Jim, I think the only reasons for not using solid fiberglass for any part of a boat are cost and weight. Bernie
I'm thinking enough fiberglass to hold screws without going through for better waterproofing and holding, and what's left is waterproof core. Transom jobs are getting expensive. I'm thinking clamp up bushings too. Jim
Another thought - you could build a thicker transom except where the I/O housing attaches. Taper the plywood as shown in the pic for easy glass cloth application. Granted this is for a ski pole mount but the same concept could be used with the bevels facing inward towards the mounting points for the inside part of the I/O mount.
Was going back through some threads and now I'm really confused. Here are the stats on the three Hydrodyne 20 I/O Serial No's Vann's 1983 is THIC000183G Kevin's 1985 isTHIC0002B485 (my boat) Ashley's 1988 is THIE000G788 Not sure how this transulates to the # produced and other info presented. THIC is Three Rivers Industries Corp, 000# is spacing for more production as in up to 9999 per year I am assuming, however Ashley's boat has a 000G, G being #7 in the alphabet, maybe for Ashleys boat???? the B after the assumed production # with my boat (maybe alpha for #2 boat), 485 for my 1985 would suggest Apr85 and 788 for Ashley's boat would suggest July88, but the 183"G" for Vann's boat doesn't correlate directly, unless this was the 7th hull produced in 1983?? Is this non-sense or does it make sense?? I remember someone posting a translator out on the sight some time ago but by what I am seeing, I think the boat builder took some laditude on how they identified their boats/production. Any thoughts? Kevin-
Kevin and Ashley thought I would check in. My boat is still running perfectly and used every weekend. Would still love to get these 3 boats together before it's to late. As far the hull # I know my boat is a prototype which I assume was the only prototype so 001 it boat #1 and 83 is the year. Vann
Hey Vann: Wow, Two year old post and it gets a hit. You and Ashley are in the same neighborhood but WI to AL or GA is an event, not just a weekend outing. May see how the late summer plays out but it has really just arrived up here (kinda crappy spring as usual) Will update the Site/post with some pics. Really enjoyed the 85's performance after getting the electronics and timing sorted. Had a couple times where I was at the end of the rope as well. Will be in touch, Kevin-