# Lead vs cast iron keels



## Gregrosine (Feb 10, 2013)

Any opinions on the advantages of lead vs cast iron keels? With the additional mass of lead will a lead keel give a better ride than a cast iron keel?


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## jsaronson (Dec 13, 2011)

lead will give you a lower center of gravity than a cast keel of the same size. Alos, no corrosion issues. Lead is WAY more expensive!


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## msmith10 (Feb 28, 2009)

Yard guys also claim lead absorbs a grounding without transmitting as much force to the hull. I think there's truth to that in small or moderate hits. Of course, hitting a rock a 6+ knots with either isn't going to have a good outcome.


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## night0wl (Mar 20, 2006)

From what i understand, the only advantage Iron has over Lead is that it tend to have better adhesion to epoxies and bottom paints. Get lead if you can.


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## PCP (Dec 1, 2004)

jsaronson said:


> lead will give you a lower center of gravity than a cast keel of the same size. Alos, no corrosion issues. Lead is WAY more expensive!


On modern keels that is not very meaningful. They are made of steel for the foil and iron or lead for the bulb. The difference on the CG is not significant. What is significant is the size of the bulb and the associated drag.

Considering the same boat the one with a lead bulb will be slightly faster than the one with a iron bulb but the difference is much lesser regarding the time where the keels where all cast Iron or cast lead. There you would be right regarding the considerably lower CG on a lead keel. To compensate that the Iron keel would not only be bigger (more volume) but also heavier.

That would count negatively on the boat performance on two counts: Drag and weight.

Regards

Paulo


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## benesailor (Dec 27, 2012)

I have a iron keel and have had some very minor corrosion issues. I would agree that you can get a lower center of gravity with the lead but, i would think that is also factored in during design regardless its iron or lead. I will say; my neighbors 40" columbia hit something in the NYS Barge Canal (looks like it was steel) and just shredded his lead keel!! He has a 2" gash. I would have had a scratch. 
I would say that the maintenance issues with a iron keel are way overrated.(mines 20 yrs old, in florida salt) If it did start to rust out it would take 20 years to corrode off its so thick. Now, the amount of give VS a iron keel? I don't know. I would assume they would be about the same if you hit a rock. I would hope a lead keel wouldn't fall off or "give". Not well versed in this department. 
I would think that having a bolt on iron keel may actually present fewer maintenance problems. No "smile" or separation issues between GRP and lead to worry about. It is one solid component. 
I used to think nothing but lead; i have changed my mind. I have actually read some modern designers prefer iron for it's durability. Please don't ask me to find that. It's in one of my books. 
This is a long ongoing debate. Then again, what do they use in a Oyster, Morris, Passport, Discovery, Swan? Lead


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## benesailor (Dec 27, 2012)

I would definitely agree about iron be a drag issue vs a steel fin and lead bulb. 
In a cruiser; does it matter that much?


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## msmith10 (Feb 28, 2009)

Agree with Benesailor. Iron keel wouldn't be a deal breaker for me.


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## MarkofSeaLife (Nov 7, 2010)

The price difference is pretty large, something like $2,000 per unit.

Anyway, if Oyster uses them then they are good enough for my boat.


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## SloopJonB (Jun 6, 2011)

msmith10 said:


> Yard guys also claim lead absorbs a grounding without transmitting as much force to the hull. I think there's truth to that in small or moderate hits. Of course, hitting a rock a 6+ knots with either isn't going to have a good outcome.


Bill Garden said the opposite - iron bounces off while lead "forms" around rocks & such. I've seen boats with iron bounce off and keep going but every lead keel I've seen hit came to a dead stop. Those observations would seem to back up Garden.

Iron keels also have the advantage of having removable and replaceable keel bolts whereas lead keels must have radical surgery or be re-cast to replace corroded bolts.

Properly coated iron keels do not present much, if any problem re: corrosion.

As far as performance, lead is unquestionably best, except for depleted uranium.


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## killarney_sailor (May 4, 2006)

benesailor said:


> I have a iron keel and have had some very minor corrosion issues. I would agree that you can get a lower center of gravity with the lead but, i would think that is also factored in during design regardless its iron or lead. I will say; my neighbors 40" columbia hit something in the NYS Barge Canal (looks like it was steel) and just shredded his lead keel!! He has a 2" gash. I would have had a scratch.


If you think about the physics involved, if you hit something the energy involved has to go somewhere. With a lead keel much of it goes into deformation which is a pretty easy fix. With an iron keel, most of the energy gets carried upward into the hull and is a good opportunity to test the integrity of the keel/hull joint.

Iron keels came into use because they were cheaper and this became even more of an issue as lead prices soared. Some builders offer lead as an extra-price option and it is significant. To me it would not be a deal breaker, but I would certainly prefer lead.


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## PCP (Dec 1, 2004)

benesailor said:


> I would definitely agree about iron be a drag issue vs a steel fin and lead bulb.
> In a cruiser; does it matter that much?


No and that's why now on almost all modern mass production boats the bulbs are in iron. It only maters to someone that wants to maximize performance and only performance boats offer that, many times as an option. But I am only talking about the keels that now are the norm in Europe. On all cast (iron or lead) the difference can be considerable between the two, in drag and weight that also affects performance.

Regards

Paulo


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## ATI2D (Jun 8, 2015)

Where do you get depleted uranium cores? From ATI2D


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## SloopJonB (Jun 6, 2011)

You don't


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## Stumble (Feb 2, 2012)

If you really want to go dense get some osmium. It's about twice as dense as lead.


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## Don L (Aug 8, 2008)

you want dense you need to use a lot of forum brain matter


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## aa3jy (Jul 23, 2006)

A compromised (showing signs of internal corrosion)iron keeled vessel will be hard to re-sell..


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