removing concrete keel in a cp 16/1

[skip1930]

Road building....re-bar encased in cement turning to concrete over the years [ lets say 80 years ] does not turn to rust if it stays dry and sees no oxygen. Just a thought.

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[Koinonia]

one way to think of less weight in the keel to achieve balance is to look at aircraft.  If you know a guy who flys they he will know about weight and balance.  Weight times arm equals moment is the formula though with our boats its just vertical instead of horizonal.  It all goes to the lever or teeter totter.  There are many other formulas to go with this but they are in my pocket manual of good math stuff at work.

[skip1930]

To add a thought;

On my CP-19 there is an open void in the stern of the keel where not so much weight is placed in this area...meaning the weight is fwd more than astern. The open area is my 'ice box' and where the bilge pump is located...under the potty.

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[Allure2sail]

Hello:
Question asked was does a cubic foot of iron or cold rolled steel (whatever it is they mix in with the cement for ballast) weigh as much as a cubic foot of rust left over from it corroding to a powder. Maybe I'm all wet (pun on words) but I cannot accept that they would weigh the same. The volume would be the same but the mass has changed. I do work in engineering and it is as a mechanical designer. Someone help me out here. Is it not like saying a cubic foot of water weighs the same as a snow. The characteristic of the material has changed.
Bruce

[NateD]

Hello:
Question asked was does a cubic foot of iron or cold rolled steel (whatever it is they mix in with the cement for ballast) weigh as much as a cubic foot of rust left over from it corroding to a powder. Maybe I'm all wet (pun on words) but I cannot accept that they would weigh the same. The volume would be the same but the mass has changed. I do work in engineering and it is as a mechanical designer. Someone help me out here. Is it not like saying a cubic foot of water weighs the same as a snow. The characteristic of the material has changed.
Bruce

I'm no expert, but I know how to google. From what I've found across a number of sources (http://www.engineering.com/Ask/tabid/3449/qactid/-1/qaqid/2499/Default.aspx) is that the weight will actually increase as the iron turns into iron oxide through the addition of an oxygen molecule. So as long as none of the rusted iron is washed out of the keel, it would actually weigh more (assuming the iron does rust when fully encased in concrete). Although I'm guessing that the increase in weight it going to be pretty negligible.

[Allure2sail]

Hi:
I'm not talking weight to weight. Of course a pound of rocks weighs the same as a pound of dirt. Does the volume occupied by the scrap metal (be it steel or iron) weigh the same when it turns to all rust. So the question remains the same. Does a cubic foot of solid steel or iron weigh the same when it rust away to a powder? Hope I explained the question better, I am talking equal volumes not equal weight. If you can find the mass properties of rust let me know LOL.
Thanks
Bruce
Just noticed  the email from NateD, interesting reply.....I'll check out the website.

[Koinonia]

alot of interesting thoughts, to bad the C27 doestn have much access to the keel area inside, can you imagine the storage gained by going from concrete to lead.  The 27 has a ton of easy access storage already though.