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.

 

[JohnnyP]

Thank you so much for the replies. Now that I understand it better, I will take a closer look and try to understand what I have going.

 

[JohnnyP]

I went down to the boat, cleaned up the bilge to take a better look, and took some more pictures. I attached more pictures. The second picture shows the bilge with cracks on the flooring. The cracks are actually on the paint as the paint comes off of wood. It looks like fiberglass was used to glass in the wooden flooring to the hull. I used a marker in the 2nd picture to outline the edge of the fiberglass.

The first picture looks pretty bad. Not only is the paint coming off the wood flooring, but it looks like the fiberglass might be lifting off of the wood flooring as well. It looks like it is happening more due to the wood falling apart than a huge stress like running aground hard. The wood seems fairly hard and intact except the top layer is peeling off. The third and fourth pictures show a chunk of paint that I took off. You can see some wood attached to the paint chunk. This is showing that the top layer of wood is coming off.

What are your opinions on what I should do? When the fiberglass is still attached to the wood, it seems like I can just take off the paint and give it a new coat. If the fiberglass has separated from the wood, I can clean it all up and fiberglass across the face of the flooring from one section of fiberglass to the other. I really do not want to pull all the wood out and repair everything. The boat is a 1984 and I bought into it for $4000 a couple years ago. It is for fun but I am not trying to retain value really.

Several people asked if it has run aground hard. I do not know. I bought the boat a couple years ago and the previous owner passed away. I am sure he took many secrets with him.

Thanks for your thoughts!

 

[jviss]

First of all, great pictures and explanation. Thank you!

You know, these boats, and most contemporaries, weren't built as if they were meant to last forever. Yours is at least 37 years old, and perhaps as old as 48. As someone else said, they used wood for the floor and encased it in fiberglass cloth and polyester resin. Whether the glass was structural and the wood not is debatable, in my opinion.

I wouldn't worry about it unless it becomes "mushy," and the rigging slacks, etc. Keep the limber holes clear and the bilge as dry as possible and you should be fine.

It's fine to repair the paint or gelcoat, whatever it is, but it probably doesn't really matter.

 

[jssailem]

This image appears to show deterioration of the wood due to moisture. Suspect this has come from water in the bilge. Water getting through cracks in the glass lining the bilge and breaking any FPR/Wood bond.

Understanding you are not looking to rebuild the internals of the boat to "Pristine" condition. Plan to do what will make this mature boat safe and seaworthy.

I would peal back the loose and cracked fiberglass/paint to inspect the underlying wood. You need to get the moisture out of the wood before you can reseal the area. Just painting will not give you a good seal. The paint won't last a season to wet wood.

You say there is unknown history. I would want to assure that the keel is soundly affixed to the boat and sealed to eliminate water intrusion from the keel and hull into the bilge.

Once dry I would grind out the bilge to sound material and reglass. Then I would paint the bilge with a 2part epoxy barrier coat. That would eliminate further water intrusion from the bilge into the sub floor supports.

How far you go, if it were my boat, would depend on the soundness of the materials and ease to which I could make them reliable.

Columbia used good materials and were known to make a solid boat. Certainly your acquisition costs are favorable. Further investment into the boat then is dependent on how much you like the boat and how it fits your sailing desires.

I share this like for solid boats with history. After sailing on my boat for a year I found it well served my desires. When faced with scrapping the boat of rebuilding the engine/transmission I ended up making the investment. I am just now getting to the point I might reap the rewards of this folly.

 

[PaulK]

The new pictures make it look like your floors were made of plywood that was 'glassed into the hull where it butted up to it and then painted, rather than overcovered with fiberglass. The plywood has obviously gotten wet and started to rot. It is probably also delaminating (the layers of the plywood are coming unglued from each other), along with the tabbing that attaches it to the hull. Some of the floors are in better shape, but the ones that need fixing definitely need fixing. Jssailem's suggestions seem on target. It might make sense to grind things back and then 'glass all of it over to add strength to the bilge area.

 

[JohnnyP]

First of all, great pictures and explanation. Thank you!

You know, these boats, and most contemporaries, weren't built as if they were meant to last forever. Yours is at least 37 years old, and perhaps as old as 48. As someone else said, they used wood for the floor and encased it in fiberglass cloth and polyester resin. Whether the glass was structural and the wood not is debatable, in my opinion.

I wouldn't worry about it unless it becomes "mushy," and the rigging slacks, etc. Keep the limber holes clear and the bilge as dry as possible and you should be fine.

It's fine to repair the paint or gelcoat, whatever it is, but it probably doesn't really matter.

Great thoughts! Let us talk about the slacking rigging. When I am in strong wind and the boat is heeling a lot, I look at the leeward fixed rigging and it is a little slack. I assume that is what you are talking about? I suspect my rigging is a little loose and needs to be tightened up. That is on the to-do list. Assuming the rigging is adequately adjusted, is there a rule-of-thumb on how much slackening of the rigging is acceptable?

 

[dlochner]

Great thoughts! Let us talk about the slacking rigging. When I am in strong wind and the boat is heeling a lot, I look at the leeward fixed rigging and it is a little slack. I assume that is what you are talking about? I suspect my rigging is a little loose and needs to be tightened up. That is on the to-do list. Assuming the rigging is adequately adjusted, is there a rule-of-thumb on how much slackening of the rigging is acceptable?

Let's take the rig tuning questions to another thread to avoid thread drift and to make searching the archives easier for future current and future members..

 

[jssailem]

is there a rule-of-thumb on how much slackening of the rigging is acceptable?

Your rigging needs to maintain your mast in a vertical column when viewed. If your stick has a wave or a sideward lean, then an adjustment is needed.
Fore / Aft lean is considered "Rake" and is adjustable to get a balanced helm with a smidgen of windward helm.