Re: Transom Materials?
Similar situation and similar thoughts about transoms.
I'm looking at a boat that can last hundreds of years and a transom that could begin to biodegrade in a few. Yup, even wood that has been treated under pressure with preservatives for ground contact can begin to decay in under a decade when exposed to the elements, so I'm not liking the wood option all that much either. All it takes is the right combination of moisture, temperature and air and a teeny little bug to drag the growies that eat wood in on its hind leg to start the process all over again. I don't like the odds.
Another thing.....the weakest, most flexible part of a transom is also where you mount the engine (outboard) A plank is strongest along it's width, not it's thickness. Support a 12 inch board at each end, lay it on it's side and stand on it...it bends....if you jump on it, it might break. Stand it on edge and put weight on it, it won't. No telling how much pressure you'd have to put on it to break it....tons? So the board in a transom would be a lot less prone to flex and break if it were rotated 90 degrees or had components that were. I haven't looked at a huge number of transoms, but I'm guessing the design of most of them ignore this common sense fact.................... ..........................
And as far as the philosophy about being too old to care about it a few decades from now....well that's what the jerks who originally built it were thinking, but here we are. HAHAHAHA
The wood transom I'm replacing right now is exactly 46 years old, it came out in one piece. Its wet, and pretty rotted around the lower edge, but was still supporting the motor and the transom did no crack. The wood is not treated, and is nothing more than two sheets of 3/4" plywood which was glassed in when the boat was molded. I plan to remake a new wood panel, coating each sheet with epoxy, and laminating both together with a layer of glass cloth in between. I also will predrill oversize holes where needed and epoxy in those areas as well. The original wood had no such coating or thought taken as to longevity but yet it lasted 46 years and was still doing its job well enough to not break. The wood I put in it will be protected a hundred times better, be far stronger with the added epoxy and glass layer, and will not have all the air gaps around the edges that the original panel had.
By the time that the wood I put in is even a concern, I'll be too old to care. If it lasts another 40 years, I doubt I'll still be running this boat. It would surprise me if I still own it in 5 years from now.
To do this in Nida Bond, I'm looking at two buckets, at $320 my cost with shipping, plus the added work of blocking off the bilge, building a temporary front panel and spacers to hold in the poured resin and filler, and then I still have to glass in the forward panel when I'm done.
This boat has a sealed lower bilge area, the deck is fiberglass, as are the stringers, so it's still in place. The inner skin of the transom was no more than a rag once the wood was removed. Since I'm doing this with wood again, I just cut around the edges and peeled it off, I'll most likely just glass the same panel right back in place with some strips around the edges for added strength. There's no side structure, just a single wall outer hull and the transom wood stops 3" short of reaching the top cap or gunwales in this boat.
It would be nice to think that if I were able to just pull out the old wood and dump in some resin with the drain tubes in place and be all done but the real fact is that I'd be looking at a few days of building a frame and support for the inner transom, dealing with a way to hold the drain tubes in place to just get ready for the pour, then I also have some concerns about the heat produced when curing and how thin this hull actually is. When I did the Seacast, the stuff got so hot it smoked or steamed for 45 minutes when it began to cure. But on that boat the transom panels were 3/16" fiberglass, the MFG's outer hull is single layer glass less than 1/8" thick with basically no inner support. The splashwell is held in with self tapping screws and a rubber bead along the edge.
If I could drive over and pickup the Nida Core locally, and save the shipping, it might help make me consider it for often on more boats, but on this, its just easier to use wood. I do have a few boats were a poured transom would be the ticket, mostly on any boat where access to the transom wood means cutting or damaging the original structure.
For me, the shipping on the stuff is about $60 per two buckets, add a third and the shipping jumps to $90.
