I also am getting ready to do something similar to my boat, a 45 foot Dutch custom steel ketch
. That is what brought me here to read this in the first place. I have a bilge
area under the engine
that I want to reshape to get the water
to collect in a plastic sump that I can easily pump and let the last 1/4 inch safely sit away from the steel
in the bottom of a cutoff plastic bucket instead of the inside of the steel hull
. So I was thinking 6 inches of shaped concrete with a bottom of a plastic bucket forming a sump. I was thinking concrete since it is cheap
and easy to work. The rest of my ballast is concrete and as far as I can tell it has not had a problem with causing steel hull corrosion
. Maybe the Dutch steel boat people know something about concrete we don't know. There has been a problem at the steel area just above the concrete, but that was because my boat was stored for 8 years on the hard
and collected rain water
and allowed to rust through. I don't see any problems caused by the concrete, it was just the stuff that kept the water at that level on the steel. I'm sure the steel probably was painted with epoxy
before the installation
of the concrete and the concrete was painted with epoxy
after it had cured when the boat was first built. The big problem with the design of my boat was lack of bilge access to allow periodic maintenance
under the cabin
floorboards due to poor placement of tanks
and also the anchor
chain locker draining saltwater through the entire length of the bilge instead of quickly out through the hull
at the bow.
I'm just adding my confusing observations and thoughts to throw into the mix here. I'm still up in the air as to what's right but I will need to do something soon. The time has come to address this problem of water on steel in the bilge below my engine
while the engine room cover/cockpit floor is removed....
Maybe concrete is OK if the steel is painted with epoxy before the concrete is installed, the concrete will protect the epoxy and the epoxy will protect the steel.
Good luck with whatever is decided. Jon