Do I have a stringer problem?

[JohnnyP]

I am a little afraid to ask this question, for fear of the answer.

I attached 3 pictures of my bilge. The bilge is separated into compartments by what I believe are stringers? The first picture shows the bilge with a small hole that allows liquid to go through the stringer. You can barely see it in the picture. It is right at the water level. When I stick my finger in the hole and feel along the 'wall' of the hole, it feels like soft wood instead of hard fiberglass. If there is a wood stringer in there, it seems like it should be protected from any water...

The second picture shows cracks in the fiberglass that would allow water in if the level got higher. The same with the 3rd picture.

Do I have a problem?

Thanks!

 

[shemandr]

There should be limber holes to allow incidental water to drain to the lowest part of the bilge and hence be pumped out. In production boats it's not hard to believe that the holes are not sealed with resin. There may be marine ply in there or rot resistant wood like white oak but maybe not.
Anyway looking at your pictures it looks like the tabbing has failed - but it's hard to tell from a few pics.
I think there is a problem.

 

[garymalmgren]

Do I have a problem?
Yes.
Is a big problem?
No.

The supports that support the floor are called floors and the floor is called the sole.
Do you soles squeak when you walk in the cabin?
You have a very common case of rotten or badly deteriorated floor(s).
This happens in "production" boats that are built to a budget and time line.
The ply is probably not marine grade (or low quality if it is).
The end grain had not been sealed with epoxy but with cheaper polyurethane resin.
The limber holes are way to small so they get blocked and water is trapped and the floors are tabbed in or covered with glass and poly resin. Poly resin does not bond to wood (or ply) as well as epoxy does.

You have two choices.
1. Put the sole boards back down and pretend that you haven't seen it. (My choice at this stage)
2. Bite bullet, Grab the ram by the horns.Leave no stone unturned. Put your shoulder to the wheel.
And dig them out and replace them properly

gary

 

[dlochner]

Those photos are facing aft, correct?

Yes, you have a potentially big problem and it is not necessarily the rotted wood.

The stringers, also sometimes referred to as floors or floor timbers, are wood encased in fiberglass. If the floor is well designed and built there should be a fairly thick layer of glass surrounding them because the strength of floor is in the skin not the core. In theory, the core is not necessary, but it is good to have. The core simply keeps the two sides of the box around it from bending inwards.

There is a party trick that demonstrates this. Take an aluminum can of bear, set is straight up and then stand on it. It will support your weight. Now, drink the beer (the fun part). Set the empty can on a flat floor and gently step on it. If you have stepped correctly with bending the can it will support your weight. While standing on the can, have someone poke a pen at the side of the can and the can will immediately collapse. In this example the beer is like the wood your core, it keeps the sides parallel so they can support the weight and forces on the floor.

The rotting core is not what is concerning me. The concern is the cracks in the skin and their location. Cracks in this area are often caused by a hard grounding, running into something really hard like a rock at speed, or being dropped on the keel. When a boat runs hard aground the forces are transmitted through the keel and up into the hull, the keel acts like a lever amplifying the force. This can cause floors to crack and the hull lamination to delaminate. Additionally furniture can be knocked out of alignment and tabbing cracked. Repair is a big deal.

No boat damage of this nature can be diagnosed in an internet forum from a couple of photos. Indeed there may not be significant damage, however, with a more thorough on site out of the water evaluation, you won't know. My advice is to go through every nook and cranny on your boat with a bright light and look for damage and things that don't look right. Document with photos and notes. Then consult with a good local surveyor. He may want to have the boat hauled for a closer inspection. Do it.

Sorry for the bad news, best of luck. In cases like these I hope I'm wrong.

 

[PaulK]

Stringers run fore & aft. Your picture is of floors, which are used to strengthen the hull in the bilge area because of the loads of the keel. The cabin sole rests on the floors. Floors are often hollow to save weight. Like the beer can example above, their strength lies in their "box" construction and in their being connected to the hull. Sort of like how a ridge in corrugated steel makes it stiffer, even though it's not any thicker. Sometimes floors and stringers are made by applying fiberglass over a cardboard or wood form. If the cardboard or wood rots away it doesn't matter -- the strengthening shape is still there in fiberglass. Finding something mushy in your limber holes is not a problem. As others have said, the problem is the condition of your floors. They seem to have cracks all over them and to have come unattached from the hull ("delaminated tabbing") . Has the boat had a hard grounding? The generic fix for this sort of thing is to grind down the cracks back to solid material and reapply fiberglass mat, roving and resin to repair the damage. Leave the limber holes.