Dry Ice

mman30 · #1 (**permalink**) 09-06-2008

I have been planning a 6 month cruise from the Chesapeake down South for the past three years. There are only a few last minute preparations before I leave at the end of Oct. One of those issues are my ice box, and prolonging my block ice. Has anyone used dry ice blocks (1 small block), along with block wet-ice, layer of cardboard(or insulating material) then properly stored food above that. My ice box does drain to the bilge, and I am aware that the dry ice gas can suck out oxygen. I am planning on rigging a pump to drain excess water out of the ice box, and overboard via a thru-hull draining grey water from galley sink.. The boat is 30', and I don't want to do anything dangerous. Any advice on using dry ice, or retrofitting a 35 year old icebox to prolong the ice. I am also aware of not opening closing to often, pack most used on top, and least used on bottom, etc. But what are the dry ice possibilities?

Boasun · #2 (**permalink**) 09-06-2008

If you have dry ice inside the boat, you better have excellent ventilation.
Dry Ice does not suck out the oxygen, it displaces the air. For it is heavier than air. Thus your oxygen has been displaced. For this reason I never allowed dry ice taken inside the vessels that I have worked on. I know that it is extreme caution but then all of my crews are still alive. I don't take chances with with my crew's safety un-necessarily.
But a couple of coleman coolers, with dry ice, lashed topside would work. Then you could time how long it lasts. Also all of the frozen stuff transferred from those coolers will act as ice block in the ice chest down below.

Two key phrases here: Coleman Coolers & Lashed topsides.

sailingdog · #3 (**permalink**) 09-06-2008

Don't forget to lash the coolers where the sublimating carbon dioxide won't vent into the boat.

mman30 · #4 (**permalink**) 09-06-2008

There is another thread on dry ice that i should have read first. Some are saying yay, some say nay. I think with a small amount (5 pound block, that would not be enough to suffocate anyone. Thanks for the input.

denby · #5 (**permalink**) 09-06-2008

Quote:

Originally Posted by mman30

There is another thread on dry ice that i should have read first. Some are saying yay, some say nay. I think with a small amount (5 pound block, that would not be enough to suffocate anyone. Thanks for the input.

I don't know, 5 pounds is a lot of CO2.

sailingdog · #6 (**permalink**) 09-06-2008

CO₂ is toxic in higher concentrations: 1% (10,000 ppm) will make some people feel drowsy, and concentrations of 7% to 10% cause dizziness, headache, visual and hearing dysfunction, and unconsciousness within a few minutes to an hour. Depending on how large your cabin is, how well ventilated it is and what the conditions you're using the Dry Ice under are, it may or may not be a problem. Drafty, well-ventilated cabins are at lower risk...but in bad weather, with the cabin well sealed against wind/rain, you could run into some serious problems.

Quote:

Originally Posted by mman30

There is another thread on dry ice that i should have read first. Some are saying yay, some say nay. I think with a small amount (5 pound block, that would not be enough to suffocate anyone. Thanks for the input.

anchorsaweigh · #7 (**permalink**) 09-06-2008

I use dry ice often with no problems. A five pound block helps my H2O blocks last quite some time. I have plenty of ventilation in my boat, but a five pound block of DI shouldn't be a problem provided you're not in a tiny daysailor.

Cheers,

Bob

sailingdog · #8 (**permalink**) 09-06-2008

Of course, a Nonsuch 30 has about the same cabin space as most 37' boats...

They've got a huge interior.

pagansdad · #9 (**permalink**) 09-10-2008

According to my wife, dry ice will attract hordes of gnats and mosquitoes. If you will be tied up in buggy areas it may be a problem for you. Have not confirmed it personally but makes sense that the blood suckers would be attracted to the CO2.

sailingdog · #10 (**permalink**) 09-10-2008

A very good point...and no-see-ums probably are attracted by it as well.

Quote:

Originally Posted by pagansdad

According to my wife, dry ice will attract hordes of gnats and mosquitoes. If you will be tied up in buggy areas it may be a problem for you. Have not confirmed it personally but makes sense that the blood suckers would be attracted to the CO2.