Ditto the best guesses so far...water in the trunk freezing and causing that inward movement near bottom of trunk. Assuming the boat has lived in winter-freeze climates that is at some point in its life - yes? No? And to add - if it was water freezing in the keel, then once it thawed it ought to run out. Or even if it doesn't run out, the pressure it exerted when frozen is not being exerted any more once the water is liquid. You said no give to the inside bottom of the trunk. Was that just by hand, or with something stronger? If it were me I'd take a bar clamp (with pads on both clamping surfaces), put tongue up inside the slot, threaded end pad outside keel, and gently and slowly tighten. And see if there was any give when squeezing with more than hand pressure. I'd do that all along the slot, in case some areas had give and others not, because... In theory with lead ballast there should be no permanent expansion from water freezing inside (nor from rust since it won't rust). Unless...there was some loose shot here and there that moved/fell into gaps created by the theoretical freeze expansion (or anything that might have caused an expansion). And then, they are jammed in place wherever they moved/fell to once the water melts. If the resin pour with lead shot is done generally similar to the resin pour with steel punchings, you may have some loose shot here and there in the keel. My old steel punchings keel definitely has loose punchings here and there in the resin fill. And as has been mentioned before in steel punching threads, the pour resin (polyester) is not "waterproof," and so over time, even if every pellet were encapsulated, if there was any place water could access the inside of the keel, it could/would permeate to some degree. A tiny amount of water in a very thin crack in a rock can split the rock. So it doesn't take much... There's also the possibility of manufacturing defect on that particular boat, but it seems unlikely to me that a boat would leave Jerry's shop looking like that at the keel slot joint. cheers, John On 6/23/22 15:39, sailhavasu via montgomery_boats wrote:
I’m just gonna throw in some food for thought. I don’t know if this is correct , just throwing it out there for thought
The photo uploaded clearly shows the sides of the trunk not flush with the slot in the keel, but rather , both are pushed inwards towards the center of the slot. Considering that I’m guessing the thickness of the trunk wall ( visible) looks to be about 1/8” , you appear to have lost at least 1/4” plus of slot width. That’s a lot. Because the keel is filled with lead shot impregnated with resin , yes , probing into that seam is gonna hit something hard. However , consider , this is thousands and thousands of individual lead shot , that was “saturated” with resin from the top. Having cut multiples of these keels apart I can tell you the at the shot is not 100% saturated. As such , while you may not be able to probe in very far and it appears solid , a liquid can and will easily infiltrate that mass of shot where it’s not perfectly saturated just like water runs through coffee in coffee filter. Being that it is lead , rust should not be an issue that’s causing swelling. Theoretically the water “should” just run back out. I thought it very insightful though that someone brought up the possibility of water remaining in the keel possibly freezing and expanding. I can totally imagine a scenario where when the keel is full submerged , water will fill any voids, including going “up, around and over “ an area saturated with resin , but possibly not able to go “up and over” to get out ….. then just sitting there?? It’s definitely a plausible scenario. Freeze that water and it’s gonna expand. Not saying that is what happened but it’s definitely a theory.
Regardless … SOMETHING has expanded both sides of the keel trunk inwards. And split that bottom seam. My personal take is that needs to be closed up to maintain the integrity of the cavity from further water intrusion.
I will end with this. These things are frustrating. A lot of times we never can totally pin down “what” exactly caused the issue. It’s quite often even a question if “did the board swell or did the slot shrink?” I’m pretty sure in your case from your photos and description it appears the latter. Hang in there. These repairs suck and literally can dang near suck the life and enthusiasm out of whoever is having to deal with them. The most important point….. keep the faith! You’ll get there. There’s some really good minds on here and I’ve already seen some of them respond and they’ll help you get it figured out.
Hang in there !!
-- John Schinnerer - M.A., Whole Systems Design -------------------------------------------- - Eco-Living - Whole Systems Design Services People - Place - Learning - Integration john@eco-living.net - 510.982.1334 http://eco-living.net http://sociocracyconsulting.com