Reinforcing a keel with a deep sump

[Searles]

The yacht in question,a full keel 36 ft double ender ,li don’t remember the design ,it was American ,and had tanks in the keel ,as well as a good sized sump ,it was a major job to remove every thing in the keel area to glass reinforcements from the inside so the exterior shoe was fitted ,the owner skipper hit some hard stuff in Numea ,said the keel was fine ,also did a similar one on a Breuer 46 oceananic also tested fine .⚓️⛵️

[jpendoley]

I will be at the boat tomorrow and will grab pictures and measurements. This discussion is helpful!

[jpendoley]

Pictures are not very helpful-its a cave in there with hoses and pumps etc. I do have a possible plan though and would like to run it by the group for feed back.
I cross posted this on another forum:

"Hello everyone,
I have an interesting design/repair challenge on my new to me Pearson 424 and I'm looking for a well thought out plan to repair/rebuild the keel. The back story is my boat was improperly lifted on a trailer and the sump was cracked. The design (Pearson-Bill Shaw) is an 1980 cruiser with a long keel and detached rudder on a skeg. Displaces 22,000 lbs. The keel has a four-five foot long, deep and obviously hollow sump. Ahead of and behind the sump is well encapsulated lead ballast. The sump has been repaired well (from the outside in) by removing laminate and then relaminating biax and epoxy from the outside of the keel. I did not do the work, but I've done a fair bit of glass work and I'm convinced the repair is as good as factory. This area from the factory is a vulnerable spot in a grounding and more importantly, because the sump is so long it makes hauling with a trailer at a ramp very challenging. I am at a DIY yard with only a ramp and trailer-no travellift-trailer hauling is a requirement and I want to remain there.

Question is this:
what would be a viable way to reinforce the sump from the inside such that I can lift the boat on a trailer with the sump resting on the trailer crossbeam? A respected fibreglass repair man recommended laminating white oak to fit in the cavity snugly as possible and then covering the whole assemby with "pourable transom". This sounds like RJAY 6011 and some other products I've seen used for coring on transoms. He suggests of course abrading all surfaces and laminating the oak with epoxy first. The wood would not rot (he supposes) as it would be encapsulated.

I have a few concerns:

1" This stuff seems to have a lot of compressive strength but lesser bonding strength. Also for a supporting beam, I would think tensile strength would be more relevant.
2. Adhesion-this would be a secondary bond-wouldn't epoxy be a better bond?
3. Heat-I imagine the beam would be at least six inches tall by four to five long. Thats a lot of epoxy or "RJAY 6011 or "pourable transom"-how to I deal with that?

Has anyone done a similar repair with good results? Can anyone suggest a better approach or confirm the utility of the proposed fix? All input much appreciated.
Jim

[Salty Possum]

If I wanted to bear weight in that area I would be reluctant to trust any solution that depended on adding structure to the bottom of the cavity. It is the walls that would need to be reinforced, but how certain can you be that your added structure will take the load off the old fiberglass.

I like the idea of a steel shoe on the bottom of the keel that spreads force fore and aft into the part of the keel built to take it. I have heard of, but not seen, it being done with an I-beam which would minimize flex.

[Searles]

Unless the inside of the keel cavity can be cleaned and sanded to a verry high standard I for one would not consider trying to glass or epoxy anything to the inside of the void,plus how thick and or strong are the vertical keel sides would expect at least 1/2 inch plus with vertical floors at least every 15 inches for the entire length well glassed in as a minimum .⚓️⛵️

[neilpride]

Originally Posted by jpendoley

I have a Pearson 424-the design has encapsulated ballast forward of a very deep sump. The safe blocking spots are in front of the sump (beneath the encapsulated ballast) and aft of the sump where there is either very many layers of glass or more encapsulated lead. Supporting or lifting the boat beneath the sump will damage the sump cracking the relatively thin keel in that spot. Now that my keel has been damaged and thoroughly repaired, I'd like to further reinforce this area for two reasons:

1. In the event of a grounding on the sump it would be nice to know I wasn't in danger of a catastrophic failure, More importantly...

2) I want to launch and retrieve my boat from a trailer ramp. I store at a diy yard and they don't have a travel lift but they do have a wide and deep ramp. They also let you do all your own work which is a necessity on my budget. Though the keel has been correctly repaired, its still not strong enough nor was it ever strong enough to support beneath the sump-that makes hauling via a trailer difficult or impossible as the sump is very long-like four to five feet long- getting it on a trailer while in the water is extraordinarily difficult because of the fairly small areas on the keel that are safe to lift under. Haul store and launch is 3500 at my diy yard vs 7200 in a full service yard with a travel lift. That and the fact that I can do my own work is compelling.

My question is how to reinforce the keel from the inside so that the keel can be supported throughout its length either on a trailer or on blocks in the yard. The sump is deep and wide so access is conceivable for glass work and I do have a fair bit of experience. I'm just not sure how to structure the repair. Floors? An encapsulated foam base? Would love to hear suggestions.

Is your boat built in two molds or split molds I think? It is very difficult to roll a sufficient quantity of FG in a deep hole, here what they should do is extend the ballast in the entire area of ​​the keel and roll FG on top, it is very usual that when a travelift operator puts the 2 slings and the aft sling catches at the end of the aft keel causes damage.

I wouldn't think about it, you should perhaps seal the gap of the 2 molds with FG from the outside, fill inside with something until you have a distance that it is easy to laminate , then filling and seal it, I am not telling you to add 1 ton of something, but enough so that you can seal the top comfortably.

[Benz]

If you can get a really good prep--I mean grind down to good clean glass; no remnants of paint or hint of oil/bilge scum/etc--I would just add layers of glass cloth, starting as high up the hull as possible, and carrying on an equal distance up the other side.
Use Vinylester and keep adding layers until you've built that thing up into a thickness nothing could penetrate.
You could start with smaller bits at the very bottom, then use progressively wider layers as they climb the vertical sides so that you don't wind up with a huge messy ledge of material at the upper end of the job.

[jpendoley]

Thank you everyone for the feedback-it’s been clarifying. I think the upshot is this: this particular design is problematic to haul on anything but a proper travellift. That’s a bummer in the sense that I will need to find a new yard that allows DIY work in New England, but they do exist. The overall scope of this particular project makes a move to a new yard easier than a modification to the keel. The keel is now stronger than it was when it left the factory in any case. Thank you again for the group feedback-helps to keep project creep under control!
Jim