Keel void .. need to filling

[mohamedshaheen]

Hi all
I have a huge void in my full keel I was draining water for more than 20 mins from a 1/4 inch drilled hole.
The keel is made of concrete and cast iron.
I was thinking to fill the void back with concrete but the 1/4 inch hole is not big enough to pour it in.
Does any one know any material that is liquid enough to go through 1/2 inch hole and harden “other than epoxy”
Epoxy will generate a lot of heat with that big void, and I can not add it in multiple time as I am not sure if the paths the void has so may be first patch will block second patch path to the void.
I also thought polyurethane foam but it react too fast I will not be able to pour it.
I imagine the void will take about 10 mins minimum to fill from 2 holes as it took at least 20 to empty
Here is a link to a video of the draining process

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[boatpoker]

That water is far too clean looking to have sat is decomposing concrete and rusty iron. You need more investigation as to where it came from.