Mid cabin stringer repair

[BobCT]

I posted about this late last summer. I had a hollow area on my starboard side, inboard stringer. There are two vulnerable spots in that area, the big cutout in the stringer which I believe is used for the generator raw water intake hose. The limber hole is also a potential issue.

As usual, I thought I had about a 1' section that was rotted but turned into more like 3' once I opened it up. For the repair, I used two layers of 3/4" marine ply and coated the entire surface with penetrating epoxy and multiple coats on all of the edges. I tied into the old stringer and created a long angle to increase the surface area. I used SS threaded rod which I imbedded into both new/old stringers.

In the process, I made a couple of upgrades. On the mid cabin, the factory limber holes are either a little too high or not quite in the right spot. I added a couple of 2" holes right at the hull level so there are no spots where standing water can accumulate now. Even the smallest amount of water will wind up in the keel section of the hull.

Interestingly, the section I removed was repaired at some point. The wood was completely gone and what was left was just solid 2x material with non stainless nails in some spots. It looked more like a bad home repair. This area all sounded out fine when I bought the boat but knowing what I know now, I was able to see the difference in the glass repair on each side.

I learned that borate salt can be used on stringers that are wet and where you want to prevent rot from spreading. West Systems actually recommends this so I sprayed some on the old stringer that i was connecting to. The other thing to note is that stringers are like "I" beams and all of the load is carried by the cap and the hull tabbing on each side. The thickness of the glass on the sides is not really carrying much of the load.

I have a little touch up glass work to do in the spring but I ran out of time before it got cold.

Bob

Files too big - will update with pics

[yorklyn]

Glad to hear the repair went well! post some pics when your able.