So I have a survey scheduled on a 2004 420 Sedan Bridge. I found some cracking in the fiberglass in the area where the fly bridge stair meet the upper left corner of the door under the bridge overhang. There is a bulkhead below deck in this same area. I passed it off as gel coat cracking on the 20YO boat but there may be more to it as it appears to be all the way through the fiberglass. The edges of the crack (about 4" long) are not even suggesting a shearing type of force. A little research turned up that the stringers in this boat are likely hollow. Seems it is common for people to find water in the stringers. The recommended "fix" is to cut an inspection hole in the top of the stringer and install a access port. They then vacuum out the water and start hunting for a leak. Now back to the crack. There are only two things I can think of that might produce enough force to shear 3/8-1/2" fiberglass in two. (1) The bottom, and stringers, are flexing enough and transmitting that force through the bulkhead, the stairs and causing this crack. or (2) Someone severely overloaded the bridge deck. A 3rd possibility is that water collected in this area and froze over the winter splitting the fiberglass. Has anyone heard of issues surrounding Sea Ray stringers of this era? I'm hoping it is a benign issue unrelated to anything more serious. My concern is that if there is an underlying issue, a repair to this crack will just reappear.
I don’t think the issues are related. The crack on the FB is either a manufacturing defect (too thin, poor lay up etc) or someone overloaded that section of the FB. water shouldn’t be able to get in stringers, even if hollow. Unless maybe some holes were drilled at some point. But why would bilge water be so deep to get in the stringers in the first place ?
Wish I had taken a picture. I'm not usually worried about cracks here and there, but this one had me thinking mainly because it was clean through 3/8" thick fiberglass. If there were flexing forces being transmitted through the bulkhead, deck and stairs I would expect to see gelcoat crazing elsewhere. I'm not seeing that. Other than a small patch of crazing near the anchor pulpit, the boat has no crazing at all, which is rare in itself for a 20 YO boat. I figure if the crack is moving around while under way or during haul out, we might have a problem. Otherwise, it can probably be repaired without reoccurring. Another clue is that these boats typically have a full bridge enclosure and aft cockpit enclose. This boat is mossing the aft bridge enclosure and the cockpit enclosure, and they attach to the back of the bridge deck. If the bridge deck is deformed for some reason, these enclosures may not fit anymore. Water in the stringers seems be fairly common. Evidently it doesn't present a problem, just more of an annoyance. Most report fresh water in the stringers coming from plumbing leaks in the bilge. Seems like a hollow stringer would not be as structurally rigid as a cored stringer, which led me to possible flex in the stringers.
