Longitudinal Stringer repair

[Vision36]

I have a Hunter 36 Vision that was neglected by the PO. When I bought it I knew I had a problem with the stringers. It is now time to do something about it. There is soft/rotten wood in the stringers.

What would be the best option to fix it? I am thinking of:
1. Cutting the stringers out and totally replacing with new wood and
glassing in.
2. Glassing over existing stringers building up thickness and stiffness.
3. Changing out sections of the existing stringers until it all gets
replaced

Thanks for all help and insite into this problem you can give.

 

[kloudie1]

Have ya looked at these??
http://www.jamestowndistributors.co....do?docId=679&title=Prisma+Composite+Preforms
May be something you can use??

 

[Roger Long]

As usual with posts like this, not nearly enough detail or pictures to help much. Some random thoughts:

Most of the stiffness and strength is probably in the fiberglass. If these are engine beds, the wood is probably there just to take lag bolts. Foam is often used in stringers.

You may be able to drill enough holes to dig out bad wood, dry, and inject epoxy. Drill the holes in the sides as close to the middle as possible. Like lightening holes in "I" beams, it won't effect strength much. Holes above the middle will effect strength more than those on the hull side. If you can dig out the softest wood, get the rest well dried out, and keep more water from getting in, the rot will probably stop.

Look carefully for signs that swelling of the wood has popped the stringer flanges away from the hull. In that case, complete removal and replacement is probably indicated.

Feather the edges of the holes back a few inches and patch with epoxy and glass cloth.

Take all this with a grain of salt considering the limited information.

 

[Vision36]

Have already drilled holes in the stringers every 1 foot and injected epoxy but after the stringers still hammer sound as soft.

It is the stringers that run from the mast base aft to in front of the engine (through the salon).

 

[Steve Dion]

Have you contacted Hunter? They may have some insight on this issue.

Are you sure that this boat was not a sinker? I have never heard about anything like this on the Hunter Visions!

 

[Vision36]

Steve,
When I bought the boat it had been neglected for 3 years. It sat with water in the bilge almost up to the floor allowing the stringers to soak up the water through the limber holes and causing the extended rot.

 

[CharlieCobra]

Rot crawls up the end grain of wood. Time to cut it out, replace the wood and re-glass. Be sure to do one at a time. Make sure ya have the stands set properly so she holds her shape. Contact Hunter....

 

[Ross]

What lays on top of the stringers? Is the height critical to the placement of the cabin sole? Do they follow the curve of the bilge? Are they flat and straight on top?

 

[Vision36]

The cabin sole sets on the top of the stringers. Yes the top is flat and straight and they follow the curve of the bottom. I am thinking of replacing while the boat is in the water.

 

[Ross]

The cabin sole sets on the top of the stringers. Yes the top is flat and straight and they follow the curve of the bottom. I am thinking of replacing while the boat is in the water.

You have two curves to consider; the fore-aft curve of the hull and athwartship curve of the hull which in this case will be simply a changing angle along the length of the stringer.
Doing it in the water will probably provide the best support for the hull. Picking off the curves will be the trickiest part of the job and of course you need to make a right hand and left hand stringer.

Does anyone have a good link for the tic-stick method of picking off a curve or shape?