Lead bricks for ballast in our steel hull

[Make_My_Day]

Originally Posted by S/V Alchemy

I have Torino lead ingots on our steel boat as trim ballast. They are not epoxied but simply laid like interlocking bricks between frames and stringers. I have noticed no corrosion in that area, but for obvious reasons, I'm moving them either off the boat or to a spare tank (former holding tank) in the keel where I can epoxy them into place and/or plate over that tank should I want that ballasting after water tanks get filled.


Consider getting a chain fall to move the ingots any distance.

Thanks for the feedback.

[hellosailor]

Day-
I would normally suggest dry ice or CO2 slush instead of a torch, but with the large thermal mass of lead bricks and steel? See if there is a "liquified air" or other compressed gasses supplier in your area. You can readily buy liquid nitrogen, either renting the Dewar's flask with it, or supplying your own thermos-type containers. It won't be cheap, but if you literally pour a bucket of liquid nitrogen over the stuck bricks (using a clay dam or other to confine the liquid)and then wait for it to "boil off"...that thermal cycle should break any corrosion there is between the two. Making sure the compartment has been ventilated, then go back in with a maul or sledge hammer and gently WHAP the bricks. A crowbar may not be necessary, depends on how stuck they are.
But lead bricks...any heating can cause toxic vapors. If all else failed, you could literally torch them into liquid state and then clean off the last of them and the corrosion afterwards, but that's a very dangerous (long term and short term) way to do it.
So I'd vote for freezing them, with a generous amount if liquid nitrogen or other cryogenic gas, whatever is available to you.

[Make_My_Day]

Thanks for the input and interesting approach. Gives me something to think about.

[Jammer]

I have worked with liquid nitrogen in the lab. It's dangerous.


Using a large amount in a confined area like a hull you can suffocate because the nitrogen gas displaces oxygen. And seeing as it's a colorless, odorless gas, there's no way for you to perceive the extent of the problem without measuring it. People's physiological reaction to an oxygen-deficient environment varies among individuals; respiration is mainly regulated by CO2 in the bloodstreem, not by an absence of oxygen, so you can pass out before you realize there's a problem.


I would wear an SCBA.



There is also a frostbite risk from splashes, which can cause severe burn-like symptoms, similar to spilling oil from a deep fryer. If you're not using an SCBA you would want some other form of comprehensive face and eye protection.


Lead melts at 621 F with various alloys melting at somewhat higher or lower temperatures. I will let you do your own reading on the hazards however I believe that hellosailor is overstating them upthread.

[Make_My_Day]

Jammer thanks for the heads up. I'll consider all options but start simply and see where it leads.

[boden36]

How about drilling and tapping with a coarse thread (say 1/2 UNC) close to one end of the block, and inserting some threaded rods. Then put a heavy bit of angle across the top of the compartment, drill some holes for the rod, put some nuts on and gradually tighten.



Regards,
Richard

[Make_My_Day]

Originally Posted by boden36

How about drilling and tapping with a coarse thread (say 1/2 UNC) close to one end of the block, and inserting some threaded rods. Then put a heavy bit of angle across the top of the compartment, drill some holes for the rod, put some nuts on and gradually tighten.



Regards,
Richard

Nice idea but I wonder if the lead is too soft and will just strip as I begin to tighten the nuts on the angle. Thanks for the idea.

[Make_My_Day]

Originally Posted by boden36

How about drilling and tapping with a coarse thread (say 1/2 UNC) close to one end of the block, and inserting some threaded rods. Then put a heavy bit of angle across the top of the compartment, drill some holes for the rod, put some nuts on and gradually tighten.



Regards,
Richard

Nice idea but I wonder if the lead is too soft and will just strip as I begin to tighten the nuts on the angle. Thanks for the idea.