I am in the process of doing that now. Formed loops of 1/4" OD 70/30
copper/nickel alloy tubing running horizontally along either side of the
keel bolts wired to sit about 1/4" inside the surface. Tubing is about 5'
long. Theoretically it is a good bit more than needed but without definite
data on the heat transfer through the lead and having only one chance I
figured it was better to be a bit bigger rather than not big enough. Kept
the diameter small and the runs as horizontal as possible to keep the
velocity up and prevent oil from getting trapped at the bottom of the
condenser.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"Hess cutter 56" wrote in message
oups.com...
Does anyone have experience casting copper tubing into a lead keel?
To function as a keel cooler