24' Open Rotted Stringers

Dec 12, 2021
26
27
38
Central Valley
Name
Nick
Boat Name
Skipjack 24 Open
I recently purchased an 81 Skippy 24 open. Assumed I'd done my homework well enough to know what I was looking for in solid stringers but unfortunately bought someone else's surprise. Upon changing the batteries, the screws ripped out easily from the stringers when I pulled on the battery tray which was where it all started.

I'd had a short post on the tail of another but I figured this was worth starting a new thread for the entertainment of others, sharing the process I've gone through to try and remedy the issue. I'd taken time to read about different options including seacast, blue water board, epoxy impregnating rotten soggy wood and most every option included tearing out the deck. My goal with this fix was to make something that would be as strong as the original design, wouldnt require deck removal and wouldnt leave me completely broke in the process. All things that, according to all I've read thus far, arent possible. Strange as it was with the fully rotted stringers, the deck on this boat was completely solid, no rot on the underside from front to rear and the top gelcoat and texture still looks fantastic.

A few things I've noticed about this boat and its rotten stringers is the flaws in design. The deck hatches do nothing to prevent water from flowing under the lids during rain or washdown. they also have no drip edge on the inside, meaning all the water can flow horizontally UNDER the deck, to the stringer/deck joint and down the side of the stringer. Second, most of the boats I've seen, including mine, had no caulking placed back down on the fuel deck lid which lets water flow in...with no way out. these center sections where the fuel tanks are have no location to drain from and when I was able to pop a hole in the rear bulk head in front of the engine, no less than 15 gallons of water drained out. I understand the purpose of having no flow through from the fuel tank/fish box section to the rear bilge is to prevent water from flowing UP from the bilge in the event it begins to fill. I intend to cut two 1" holes on either side of the keel stringer in the rear most bulk head, epoxying in two short pieces of 316 ss pipe and installing two cam style boat plugs in them. The last big issue is the lack of sealant that was used on screws throughout. From fuel lines to wires etc. this boat was riddled with unsealed screws through the years. With water draining down the stringers consistently for 40 years and moving through the stringers through capillary effect, I have no doubt these were a contributor as well. I also found a few locations high up on the stringer where it moves up to and away from the deck where the fiberglass wrap was very thin or cracked in some locations.

After a lot of reading, understanding of other types of construction and likely to the horror of boat purists, I came up with a way to slowly replace the rotted stringers with the deck in place. I'll work on slowly sharing some of the progress so those interested can see what was done or take it as a what not to do, depending on your school of thought.

Initially I began but cutting out fiberglass along the side of the port side tall stringer, discovering the completeness of the rot ran literally from the engine mount stringers (recently replaced) all the way to the tip of the stringer in the bow. I ended up having to cut two access holes where the driver and passengers feet would rest and one directly under where the toilet sits, making the cut 45'd so they would pressure fit back in (think jack-o-lantern top) with a minor bit of glassing and hopefully gel coat touch up when they go back in.

The stringers themselves we re-made out of 3/4 marine ply epoxied and screwed together in sections. They fit back together like a 3D jigsaw puzzle, each as they go in being bedded in loctite PL poly adhesive to ensure there are no "hard spots" or gaps anywhere along the stringer edge. After setting the lower stringers in and pulling the top stringer portions up, the are pushed using spreaders to be on the same plane so when the final center section is added, they fit together straight and and adhere to one another tightly. Each piece is coated with epoxy , screwed together with 1 1/4" ss screws then epoxied back over again. Finally all the pieces will be tied back together using epoxy with roving to fully reseal the face of the stringer mold. We tested this roving with both poly resin and with epoxy and surprised to say, the epoxy coating was flexible without cracking to a degree that would never be experienced on a boat and was much harder to tear off than the poly resin.

We'll hopefully have one side fully installed in the next few days. The front bulkhead had to be replaced as well - after removing this (connects the stringers in the bow and attaches to the step bucket, supporting the entire cuddy area. Skipjack glassed the FRONT of the bulkhead, the rear was bare, unsealed plywood and was rotted practically to dust. Next we'll be knocking out the starboard side stringer and lastly the bulkhead in front of the engine.

The product we have been using for pre sealing every piece of wood installed is an a6 NSF 61 100% solids water proof epoxy that has been tough as nails even with a bit of hammering and jamming into the old fiberglass mold. This was part of the reason we took this approach - we already had enough of this to do the job. The goal was to get all the structure replaced, pre seal it all and then seal it in so that even if some water managed to make it into the stringer cavity, it would not be able to permeate the stringer.

Will keep the photos coming on this thread as we move along. Wish us luck.

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bob311

Almost A Member
  • Dec 7, 2018
    132
    252
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    huntington beach
    Name
    bob
    Boat Name
    23' sanger alleycat, 24 skipjack open
    Great work! keep us updated. With how many rotted stringers there are you should save / make templates for the next poor SOB that has to do this. I'm sure some one would also happily pay for a precut stringer kit knowing it has already been done once.
     
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    Mike_I

    I Should Upgrade My Account
    May 19, 2006
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    Irvine
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    Mike_I
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    Cabo 216 First Love
    Don't feel bad most likely the majority of old boats have the same issue are yours. What discouraged you from trying Seacast? I've read good and not good reviews about it and Fasco 99 stop rot. It would be interesting if anyone here has any personal experience with either of them. Good luck with your project and keep us updated on your progress.
     
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    Dec 12, 2021
    26
    27
    38
    Central Valley
    Name
    Nick
    Boat Name
    Skipjack 24 Open
    Don't feel bad most likely the majority of old boats have the same issue are yours. What discouraged you from trying Seacast? I've read good and not good reviews about it and Fasco 99 stop rot. It would be interesting if anyone here has any personal experience with either of them. Good luck with your project and keep us updated on your progress.
    The biggest issue with the seacast was the volume of the stringers...i did notice that on the flybridge model, they have a short stringer adhered to the hull and a short stringer adhered to the deck with "stilts' I guess I'd call them connecting them. This setup may take a lower volume of material and thus be less expensive. The 24 open I have had two 2x10's stacked on top of each other running the length of the boat for the inner most stringers. Both fully rotted. After I calculated the volume to fill one side and looked at the cost of shipping to CA, I was well into the thousands. The other issue was I would still have to pour it from the top and dig the material in the fiberglass casting from the top - so I'd have to pull the deck out. In the way we're doing it, we can use spreaders to push the upper and lower sections away from each other, pressing the stringer hard against the deck floor, ensuring theres no gap to leave a squishy deck above the stringer. Also, after battling with the "digging" out of the rotted wood even having the side of the stringer fiberglass split open, Im confident digging it all out from the top would be a royal pain.

    Fitting the sections in have been a bit challenging, especially the bow stringer. It not only curves upward but its base angle changes as the hull sharpens up toward the front AND has to tuck through that little hole into the bow. I'm starting to feel like a surfboard shaper with a flap disc on an angle grinder. We got it very close though with that mold made from the foam board strips in the photo. The PL for bedding helped my confidence that we have a solid connection with the hull from end to end.
     
    fishgrappler
    fishgrappler
    Another possible issue with seacast is the hollowed stringer glass bowing outward under the weight/pressure of the seacast.
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    Dec 12, 2021
    26
    27
    38
    Central Valley
    Name
    Nick
    Boat Name
    Skipjack 24 Open
    Did you pressure test the fuel tank
    I havent but was in luck for part of this project. The prev owner had replaced the fuel tank in 2019, it has all the writing from barrys on it with the date, gallons etc. on top and was coated with coal tar epoxy. The 4x6 stringers the engine is mounted on and the transom was also replaced in 2019 according to the paperwork I have. After digging the rotted stringer up to that 4x6 just in front of the engine, I can see that it was replaced. Its hard as a rock and coated in resin where the new stringer butts to the old one. Although I'd find it awfully hard to believe after seeing it gutted that the PO didnt know his stringers were mush inside.

    As far as that seacast and the bowing - between the foam that was around the fuel tank and the foam around the fish box behind it, the stringer casings on both sides were bowed like crazy outward. Upon fitting the new stringer pieces on the front half of the boat (which is where we are now) it amazing to see how much of that bow the new solid material forced out. The stringer fiberglass is nearly 100% straight vertical again from the cuddy bulk head back to the fish box.
     
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    Dec 12, 2021
    26
    27
    38
    Central Valley
    Name
    Nick
    Boat Name
    Skipjack 24 Open
    The horror!!!

    Stringers in my 24 are good and original. The tank has been replaced, but I don’t know when or where.
    i must say, the fiberglass over the stringers is so darn thick it definitely appeared to be solid. They didnt skimp on material where you could see it.
     
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    SkipJack Boats
    SkipJack Boats
    Both Jack and Nick have said that the wood is mostly to lay the glass. Nick made the stringers just a little bit thicker and lays it all up over a thin form and has gone to almost no wood in the hull.
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    Dec 12, 2021
    26
    27
    38
    Central Valley
    Name
    Nick
    Boat Name
    Skipjack 24 Open
    I do agree, but if you thump it with the right tool, you can tell the difference.
    youre right. after actually seeing where its rotted vs. some of the spots where the wood was still hard you could tell the difference with a small ball peen. Im amazed that keel stringer is still hard as a rock for as much water as that center section under the fish box/.tank was holding....although it doesnt have a single screw hole in it.
     
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    Arima-bob

    Ship faced aquaholic
    Mar 9, 2012
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    Too far from water
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    Beeulzebob
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    uh....
    Screws or anything that exposes the wood is death to a stringer. I don’t get into mine unless I absolutely have to, and if I do I seal them with 5200 or epoxy and a redundant amount at that.
     
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    Dec 12, 2021
    26
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    Central Valley
    Name
    Nick
    Boat Name
    Skipjack 24 Open
    will have to add some photos. got the long key section in and secured on the new side, pulled out the old starboard side stringer last night. Most of it came out easily without tools. The entire piece of wood was surrounded in mold and rot. The only section that was a challenge was the lowest 3" of wood - it was so well saturated in fiberglass resin it hadnt rotted and took some work with a cats paw to finally let go and slide up and out.
     
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    Dec 12, 2021
    26
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    38
    Central Valley
    Name
    Nick
    Boat Name
    Skipjack 24 Open
    Here are some photos of how the 8’ key piece of the stringer bound the top and bottoms together. We bedded the center of the key into the old fiberglass with a thick bead of PL. We also coated the top and bottom and inner faces of the key with the same epoxy we coated the stringers with. The holes for the stainless screws were pre drilled through the key and a thick glob of epoxy placed over each hole so it would fully encapsulate the areas the screws went through. You can see there is maybe 8” left where my 8’ key wasn’t long enough so I’ll be making a short piece to finish out the stringer. We also gutted the stringer on the starboard side. It came out much quicker after learning on the opposite side. You can see the organic bedding that held the stringer to the hull….aka mushroom. The front stringer was in contact at the tip of its location at the bow and had a 1/4-5/16 gap that was about 20” long where it didn’t touch the hull at all. It had grown a long mushroom that filled the gap. Biggest win about the demo here was it gave me better angles to replicate so less monkeying around with the flap disc on the angle grinder. My assumption on the death of this stringer were the screw holes but I found 2 different locations where the fiberglass was never even wrapped over the wood near the deck contact points. Must have been a Friday afternoon boat interfering with Beer:30.

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    Dec 12, 2021
    26
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    38
    Central Valley
    Name
    Nick
    Boat Name
    Skipjack 24 Open
    This is the rear bulkhead (between fish box and engine). Extra squishy. There was a hole drilled through it and into the fish box approx 2” in diameter. I’m guessing it’s purpose is to puke water into the bilge from the fish box if it gets over filled. The cut hole was raw - in no way sealed from water and likely the reason the entire thing was rotted to hell. I’m planning on making a drainage system for this that won’t allow back flow from the bilge into the fish box/fuel tank area. Ideas not yet finalized.

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    Dec 12, 2021
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    Central Valley
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    Nick
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    Skipjack 24 Open
    Pic of the fitment of the keyway stringer into the upper and lower sections. Heavy bead of PL against the fiberglass squished in on the back side and a thick goopy layer of epoxy squished between the two key ways. Stitched with 1 1/2” stainless screws approx 6” apart w heads covered back up with epoxy.

    I pre drilled the keyway screw holes and gobbed epoxy up on the back of each screw hole so when tightened, the threads would be fully sealed in epoxy.

    When installing, I used spreader clamps against the outside stringers to force the keyway stringer very firmly into the keyway before zipping the screws in. Damn those things are brittle and strip out easy - a serious challenge working through a hole in the floor but all came together. Both sides done. Bulkheads left to do then roving wrap with same epoxy.

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    ShadowX

    I Post A Lot But I Can't Edit This
    Oct 10, 2010
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    Anonymous
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    Wow. This is a nightmare for most boat owners. I'm glad you have it under control. A lot of other boat makers make questionable decisions in their designs which lead to a lot of headaches for the owners down the line. Its not excusable to not have drain holes on the bulk heads or other areas where water can get in and accumulate. All those missing caulking just sounds like corners cut or lack of attention to details. I've seen it many times where simple omissions by the boat builders lead to fuel tank replacements in less than a few years. I've seen boat builders put in PVC pipes to route wires and not put in drain holes. The wires end up sitting on a pool of water for years.

    Wooden boats are a whole different level of maintenance nightmares.
     
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    Dec 12, 2021
    26
    27
    38
    Central Valley
    Name
    Nick
    Boat Name
    Skipjack 24 Open
    maintenance nightmares.
    It has been a challenge for sure. Last thing I expected to be doing was gutting the underside but it seemed like the right thing to do considering the condition and the fact that it’s going to spend its time in the ocean. I’m looking forward to the ‘building’ I was hoping for - the radar tower, hard top and a few other stainless goodies. At least the hull and rest of it seem built very tough so stringers fixed, it’s time to get this deck bloody. Hard watching salmon season open here with the boat not ready!
     
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