Lead vs. Iron bolt-on Keels

[sardinebreath]

I get the density and shock absorption advantages of lead, but I have run across several cases where keel bolt corrosion pretty much created a throw away sailboat (J bolt replacement is not cheap). Is that an area where iron can be advantageous? Wouldn't it always be possible to tap out a larger hole in iron even when there was significant corrosion? I don't really have any experience with bolt-on keels so I'm trying to educate myself in order to expand the shopping horizon. Experienced thoughts would be appreciated.

[stormalong]

Iron has big issues with rusting and stress cracking. It is one grounding away from needing to be sandblasted and epoxy sealed.

If you haven't run aground you are missing all the good gunkholes.

There are two kinds of sailors. Those that have run aground and liars.

Although it is outrageously expensive, my boat was made with monel keel bolts. In 1985 it was not as outrageous. When you consider the cost of replacing keel bolts it is not that expensive. But since that bolt replacement job is long after the boat was built it is easy to cut that cost on new builds.

[sardinebreath]

Originally Posted by stormalong

Iron has big issues with rusting and stress cracking. It is one grounding away from needing to be sandblasted and epoxy sealed.

If you haven't run aground you are missing all the good gunkholes.

There are two kinds of sailors. Those that have run aground and liars.

Although it is outrageously expensive, my boat was made with monel keel bolts. In 1985 it was not as outrageous. When you consider the cost of replacing keel bolts it is not that expensive. But since that bolt replacement job is long after the boat was built it is easy to cut that cost on new builds.

How does that work with a lead keel? Are there inserts in the lead that the bolts screw into?

The Nordic 44 is probably my number 1 dream boat. clicks all the boxes. I hope you enjoy her.

[stormalong]

Originally Posted by sardinebreath

How does that work with a lead keel? Are there inserts in the lead that the bolts screw into?

The Nordic 44 is probably my number 1 dream boat. clicks all the boxes. I hope you enjoy her.

They are cast in. I don't know if they are J bolts or straight with nuts or something like nuts to improve the grip. What I do know is that the bolts look like new after 35 years.

[JPA Cate]

Originally Posted by stormalong

Iron has big issues with rusting and stress cracking. It is one grounding away from needing to be sandblasted and epoxy sealed.

If you haven't run aground you are missing all the good gunkholes.

There are two kinds of sailors. Those that have run aground and liars.

Although it is outrageously expensive, my boat was made with monel keel bolts. In 1985 it was not as outrageous. When you consider the cost of replacing keel bolts it is not that expensive. But since that bolt replacement job is long after the boat was built it is easy to cut that cost on new builds.

If you've ever watched someone trying to remediate an iron keel that salt water got into, you'd not even ask the question!

We've had two boats with lead in the keels, and the s/s bolts looked fine on the first when she was sold, and so do the ones on this one. I can see using monel, but it may not be essential to good performance. [This boat is going into her 30th year.]

The point is that I would not avoid lead for the reason the OP suggested; and I would avoid iron. I know that cuts out a lot of boats people love. It is simply how I feel about it, having watched a guy cut a big hole in the side of his keel and work a jack hammer off the ground to get the rust and expanded iron out. Very hard, filthy work. Ymmv.

Ann

On edit: stormalong is also right about the groundings. They just happen. Especially off the beaten path. Or if you're careless about looking at charts.

[Cadence]

Originally Posted by sardinebreath

I get the density and shock absorption advantages of lead, but I have run across several cases where keel bolt corrosion pretty much created a throw away sailboat (J bolt replacement is not cheap). Is that an area where iron can be advantageous? Wouldn't it always be possible to tap out a larger hole in iron even when there was significant corrosion? I don't really have any experience with bolt-on keels so I'm trying to educate myself in order to expand the shopping horizon. Experienced thoughts would be appreciated.

I would imagine redheads could be used either.

[psk125]

Aren’t keelboat corrosion problems most likely to occur at the point where they exit the keel and enter the bilge? If that’s the case, it makes no difference what the keel is made of. What the bolts are made of is what matters.

[Pauls]

if the iron is zinc protected (and it should be) then you should have little problem with corrosion. Boats have used iron keels since the 1800s. Curlew, the cutter sailed by the Carrs, has an iron keel and celebrated her 100th birthday while they were still sailing her, I believe. Like most things, the devil is in the details.

By the way, regards lead keels, J bolts are one approach to installing studs. It is also fully viable to drill and tap the lead and thread studs into it. The threading needs to be deep to compensate for the softness of the lead.

[MicHughV]

...I had the privilege of melting down a 6,000 lb lead keel shoe that came off an old wood english boat.
...I had salvaged this old boat and had cut this large piece of lead into 3 pieces, so as to more manageable, 2,000 lbs each, which I could lower into a homebuilt furnace to melt down into smaller and more manageable ingots.

...You may wonder why, so I'll tell you that at the time I was building a steel Roberts 38 and I needed lead ingots to fill the keel cavity of my boat.

..but getting back to the topic, the lead keel had several stainless steel bolts, about 1" in diameter, side by side, with a large plate and nut on each bolt, (the side by side bolts shared the same plate) which had been imbedded into the keel.. These came " floating to the surface as the lead melted. I remember noting that the bolts had a very fine thread and they were quite long as they had to thread thru' quite a bit of wood keel.
...Despite the advanced age of this keel, by my estimate, at least 50 years or more, the keel bolts showed little wear, or other corrosion.

..it's a bit unnerving to see steel bolts " float" in a pool of lead.
..even more unnerving is to see a steel anvil and other steel odds and ends come floating to the top as obviously the original builder "cheated" quite a bit on his " lead" keel.

..I would venture to guess that most any poured lead keel may hide a few "surprises", but who, other than a home builder, is ever going to find out??

...nonetheless, the embedment depth of the keel bolts was not that much....I'm guessing about 12"...as the plate seemed to serve as the " holding" attachment. Judging from the looks of the salvaged keel, I could surmise it had seen some groundings in the past

..In later years, I ran aground more times I would like to confess too..my keel was made up of 1/4" thick steel plate, filled with the above mentioned lead.

...some of my groundings were quite spectacular, but never once had any keel related problems.

..My Beneteau has a bolt on steel keel. The only issue I ever have with it is that sometimes it will get a "bald spot" somewhere on the keel for reasons, I cannot explain as the bottom paint just comes off.

...what this all boils down too, is the way the keel, be it lead or steel, is attached to the hull. Properly done, I can't see where this should ever be a problem, but I recognize that not all keels are attached with due diligence.

...keel "separation", rusting bolts, etc, is the first visible clue. This would set off an alarm in my head and give me pause to walk away from any potential purchase.

[Pete7]

We have two iron keels so you might be forgiven thinking that is twice the problem, but its not. In reality those lumps of iron are going to be around long after I have gone.

Annual maintenance consists of an angle grinder, wire cup brush and lots of violence to remove any surface rust that appears. Then patch paint with 5 or 6 coats of Primocon and topped off with fresh antifoul paint. Occasionally I will clean out the sikaflex in the join between hull and keel or strip one side of the keel back and paint up. This is all straight forward work, bit messy but you can't really go wrong with it.

The top of each keel flares out to a thick plate which matches perfectly the curve of the hull and sits into a 1.5" deep moulded impression in the hull, so the contact area is much greater than the thickness of the rest of the keel. I think there are 7 x 24mm bolts in each keel so hopefully they aren't going anywhere soon. The foot of the keels are flat to match the ground so although both keels are angled when bolted to the hull, it's actually quite a complicated aerofoil shaped casting with slight toe in I believe to give lift. Must measure it some day.

As Ann says Stormalong is quite correct and we often run aground deliberately. So long as its reasonably flat and we won't pound drying out its not a problem. Saves all that malarkey of getting the anchor out and later retrieving it, we just park on the beach, sit back and "hit some cool ones"

Pete

[billknny]

Despite what you hear here, BOTH materials make good keels. Good cast iron does not "stress crack".

Many of the commentators are confusing INTERNAL scrap iron ballast with a proper external keel. Internal iron or steel keels are really bad news when (not IF) they get wet.

External keels are easily mantained, and a simple grounding is not a disaster. I know, my boat has an external cast iron keel that is 25 years old, and has circumnavigated twice, and runs aground at least twice a year. All things being equal, a lead keel is a better design choice, but I would NEVER make it a deal killer on a boat because, all things are never equal.

If a cast iron keel is seriously neglected and has extensive rust, it will need to be sandblasted and repainted. That must be done correctly, but it's not hard.

[Red Herring]

I have a fully encased lead keel. No bolts to worry about. Any drawbacks to that?

[capt jgw]

Originally Posted by Pauls

if the iron is zinc protected (and it should be) then you should have little problem with corrosion. Boats have used iron keels since the 1800s. Curlew, the cutter sailed by the Carrs, has an iron keel and celebrated her 100th birthday while they were still sailing her, I believe. Like most things, the devil is in the details.

By the way, regards lead keels, J bolts are one approach to installing studs. It is also fully viable to drill and tap the lead and thread studs into it. The threading needs to be deep to compensate for the softness of the lead.

The bolts on my Columbia 36 are 3/4" x 12" galvanized steel hangar bolts (like wood screws with the tops threaded for nuts) tapped into the lead keel. I've never seen another keel done that way and I think they used a harder than usual alloy of lead to make the bolts hold. After 45 years they were still holding on, I only had to replace them because the tops were rusting out under the nuts and washers.

[capt jgw]

Originally Posted by Red Herring

I have a fully encased lead keel. No bolts to worry about. Any drawbacks to that?

Just one. In a hard grounding the fiberglass can crack and allow water to enter the hull. With internal iron or steel this is really bad, not quite so bad with lead but still very hard to repair. External lead will deform and absorb some of the impact, you can then "reform" it back into shape with a big hammer. I've had to do that a couple times. External iron won't deform, it transfers all the impact to the hull which can crack the fiberglass.
I like external lead ballast for those reasons, as well as being heavier it can allow shallower draft or get the ballast weight deeper.

[billknny]

Originally Posted by capt jgw

External iron won't deform, it transfers all the impact to the hull which can crack the fiberglass.
I like external lead ballast for those reasons, as well as being heavier it can allow shallower draft or get the ballast weight deeper.

This is one of those statements that gets repeated very often, but with very little actual data supporting it. In a serious hard grounding the amount of energy dissipated by deforming lead is VERY small. Even a catastrophic collision that severely damages the hull of the boat results in a very small amount of lead being deformed, and very little of the collision energy is lost that way.

The typical argument goes like this: "Look at that mangled lead keel! Imagine what would have happened to that boat if it had been cast iron!" Quite likely--nothing. Lead deforms at loads FAR below where cast iron would crack or otherwise fail.

It is theoretically true that there are collision energies that a lead keel might dissipate and reduce hull damage compared to a cast iron keel, but it's a VERY narrow range without practical significance. In a serious grounding, far, far more important than the material of the keel is the actual design of the hull and keel, the quality of construction, and the condition of the keel bolts.

If I was designing a boat from scratch, I'd rather use lead. It's density gives you some design options that cast iron wouldn't allow. But there are excellent cruising boats out there that have cast iron keels.