Another 25 Seafari goes under the knife

[Blue_Heron]

Hopfully the problem that Conner had is not indicative to all the 25's. Time will tell.

I think if it was a defect in the design, time would have already told on these old boats. I've got a couple theories about what is going on with Connor's boat, but I'm as likely to be wrong as right, so I'll leave it at that. The bulkhead I'm planning will go from the keel to the underside of the cabin sole and from stringer to stringer. If either of my theories are correct, the bulkhead will provide strength where it's needed. Even if I'm wrong, it will provide a forward stop for my water tank and an aft wall for the storage compartment under my new hatch.

[cdavisdb]

I think adding some reinforcement is a good idea.

Further info: When mine was built, they added a bunch of foam under the bunks,between the two innermost stringers, from the bulkhead just aft of the forward hatch under the bunks aft to the next bulkhead. All of this has separated from the hull, big gaps where it used to contact the hull, a couple of big cracks in the foam. Looks like compression damage to me.

[Blue_Heron]

I guess it’s time to get caught up on the rebuild. I suppose any time you get into one of these projects it’s a can of worms. Based on PMs and conversations with Connor, I took a little detour from my rebuild plan to do a little exploratory surgery.

First, the stringers in the 25 Seafari are not the box stringers we’re all used to seeing in the Potter 20s and 23s. The main stringers in the 25 Seafari are farther apart than those in a 23. That, combined with the deeper deadrise, makes for a pretty wide hull area that’s not supported by a stringer.



And the stringers are vertical, while the hull panels they support have a deadrise of about 30 degrees in the forbody of the hull. So with a tall narrow stringer, the forces pushing on the hull panel could potentially kick the legs out from under the stringer something like this:



That’s my best guess as to what happened to Connor’s boat.

Disclaimer time: I’m not an engineer, and I don’t play one on TV. All this is just head scratching and taking a best guess about a potential weakness in this hull. Connor’s boat is the only 25 Seafari I’ve heard of with any kind of problem. But I decided to take a closer look at mine and take a “better safe than sorry” approach.

The space under the cabin sole had a “deck” of sorts. It was a piece of ¼” plywood with a thin layer of fiberglass over it and pourable foam below. I don’t have a good pic of it, but the tabbing between the “deck, and the hull delaminated on the starboard side. This could indicate some movement in the lower hull panels. Anyway, I decided to pull it out. Before:





And After:



It is interesting to note that the engine bed stringers don't continue forward of the fuel tank compartment's forward bulkhead.

To be continued…

Dave