Ballast Methodology for Steel Hulls

[carr]

First --this is an excellent forum in all aspects. Thanks to everyone here for the wide range of expertise and subjects.

I am in process of shopping for my 5th boat. I sold the last, a 48' aluminum ketch a little over 2 years ago. Since that time living ashore, I ve found that I very much miss the water and sailing. Additionally at 57 I would like to return to the Pacific in my own boat one last time i.e. before Im so ancient that it must be done by air. There are lots of places I have not seen yet and I may well be having a Ulysses (a.k.a. Alfred Lord Tennyson) moment in my life.

I ve owned steel, wood and aluminum. My favorite material is aluminum. Steel is second. Currently one of the boats under consideration is a 47' steel ketch in New Zealand. She is home built and I m not at all familiar with the naval architect (Joe Van Geils) who did her lines. Ditto the builder. I have extensive photos of her both in construction and of course complete.

When she was ballasted a combination of lead and steel was used and from what I am able to tell, this was secured in place in her keel by pouring concrete inside, I assume over the various pieces. I have a number of concerns about the vessel which I will list. Let me also predicate this by saying that I consider myself much more conversant with aluminum and wood rather than steel and never having owned a GRP or composite vessel, I know absolutely nothing about it.

In the published specs for the vessel she is listed as 2 tons of lead and 4 tons of steel cemented in place inside of the keel. Total ballast 6 tons, displacement wet (full tanks ) at 25 tons.Published specs also indicate that she has spiral steel masts, alloy booms and galvanized rigging. Mainmast is 16.5 M high,, mizzen is 12 M high.Beam is 13.9 ft, draft is 6'6.Her published plate thickness is 6mm.All tankage is integral in the bilges, 650 L of fuel and 1200 L of water.

I have seen concrete used in bilge areas in wood and steel vessels for various reasons, at times to contain boiler punchings for weight and at times to build up low areas for draining correctly. . I have also read horror stories about possible maintenance problems with it when corrosion sets in. From what I can tell of the photos of this vessel, the concrete is actually exposed in the interior of the hull. So one would think that it would be in a wet/dry cycle with salt and fresh water from a packing gland plus what ever else might contribute to draining back to the sump area to be pumped out. I read on the web where Bruce Roberts is vehemently against using concrete in this manner. I also read where some think it is acceptable. What is the bottom line on this?Looks like when corrosion starts in low areas as it will do in steel that one would be faced with chipping it all out,blasting and paint and re application. The possibility of pit through with 6 MM plate seems possible. 6 MM is advertised as used in all areas. I normally have seen steel and aluminum hulls constructed with heavier plate lower down so I consider this unusual. Any one with knowledge on this please feel free to comment.

B/D and stability. This boat it would seem, has a heavy rig, moreso than extruded aluminum spars. Provided she has the righting moment it might not be a problem. Since I dont know the architect's work or that of the builder, considering her draft, b/d ratio beam and rig she to me on first examination would appear possibly tender. There is no evidence of any inclining experiments on her. Any suggestions or comments would be deeply appreciated.

This is the one boat thats under consideration in NZ currently, It is a long way away from where I live in Veracruz Mexico and Im trying to do as much diligence as possible before investing the time and expense to go and view her. My plans would be of course extended live aboard and cruising. That having been said NZ is a long way south. Any one from NZ on the forum?? It would even be better to find someone with knowledge of this boat.

In any case many thanks to all of you for a great forum. Thanks in advance for any observations

Carr

[Boracay]

Forum member conachair recommended "Metal boat maintenance-A do it yourself guide".

I brought the ebook version ($US12). It took me a while to get the download figured (dialup timed out) but my local internet cafe let me do it for a few bucks and half an hour of my time.

I'd rate the book a "must have" for any metal boat owner or potential purchaser.

[GordMay]

There are a hundred wrong ways to ballast your steel boat – but only one Right Way, usually learnt only by painful experience...
... The boat designer will normally tell you which ballast material to use, though there is only one choice for optimum results: lead...

See the complete article: “Steel Boatbuilding: Ballasting”

Part 1:
Ballast a Steel Boat - Part 1

Part 2:
Ballasting a Steel Boat - Part 2

Part 3:
Ballasting a Steel Boat - Part 3

[carr]

Boracay and GordMay

Many thanks for the kind interest and for the links to the excellent reference. This helps.

Warmest Regards

Carr

[s/v Jedi]

Carr,

I sailed for 17 years on a 31' steel boat (van de Stadt design) with concrete ballast poured into the box-keel. We never had a problem and it never got wet because the bilge could not spill onto the concrete (steel frame welded around the opening). Only when water would go to floor level, it could overflow onto the concrete. That never happened to us.

There were other boats of the same type around with cast lead keels. The difference was that they had less ballast (but deeper down of course).

We used the space above the concrete as a natural fridge. Worked great in the cold Dutch waters ;-)

cheers,
Nick.

[carr]

Nick

Thanks very much for the informtion. there has probably been a little confusion on what I have posted here because I mistated that concrete was poured in the keel...it was not concrete but rather cement. Apparently this has been used to lock the pieces of ballast in place inside the keel area.

Van de Stadt built some beautiful boats. I bet with the water there that the free fridge worked very well .

Many thanks for the information and insight. THe idea of being able to use a keel void that way makes me cold thinking about it!!

Regards
Carr

[GordMay]

Originally Posted by carr

...there has probably been a little confusion on what I have posted here because I mistated that concrete was poured in the keel...it was not concrete but rather cement...

My confusion remains - Cement* is an ingredient of Concrete and Mortar.
Although the two words concrete and cement are often used interchangeably, cement is actually one of the ingredients in concrete. It's the fine gray powder that, in combination with water, binds sand and gravel or crushed stone (or another aggregate) into the rocklike mass known as concrete. Therefore, even though cement constitutes only 10% to 15% by weight of concrete's total mass, cement is the essential binding agent in concrete.
Mortar is essentially cement and water.

* PORTLAND CEMENT isa type of hydraulic cement made by heating a limestone and clay mixture in a kiln and pulverizing the resulting material.

[s/v Jedi]

Hmm.. I though mortar was cement + sand + water...

ciao!
Nick.

[carr]

I also since I ve not much experience with the different materials often think of them interchangeably which is of course is an error. The ballast in the aforesaid vessel is apparently held in by ...cement...and I may have used concrete at some point interchangably with this.

Although I ve owned 1 steel vessel , I ve never owned one with cement in a ballast keel. So Im pretty ignorant about this microcosm of steel construction.

Carr

[Sam Plan B]

I own a Columbia 41 with a GRP hull and cast iron fin keel. My concern with your concrete ballast is this. You should be able to inspect every square cm of the hull to verify its seaworthy condition. If unshipping several tons lead pigs - one at a time - is necessary, you should be able to do that to get at the framing and plating below. As you mention, the concrete ballast will likely retain salt or rain water. Corrosion may commence from the inside attacking the garbord strake where it is welded to the box keel. The damage will outward. Weakness will progress slowly and may not be apparent at all until you are in a pounding sea. At that point the enertial weight of the ballast may crack the weakened garbord weld and force open a seam. I have no idea how one would find or fix such a leak at sea.

[GordMay]

Originally Posted by s/v Jedi

Hmm.. I though mortar was cement + sand + water...
ciao!
Nick.

OOPS my mistake - Nick is absolutely right!

[chala]

I have noted that the boat is "home built" many insurers will not insure a home built steel boat. If insurance is not needed it is to be remembred that some marinas require a vessel to be insured. Cement and steel is no great problem after all steel reinforced structure exist all around the world and to my knowledge, cement mix are alkaline, not acidic. The vessel seems to be ancient or cheaply built, steel masts, galvanised rigging. Internal tank if you mean the one who use the hull as one side of the tank are often the source of internal rust. I think that the best move will be to contact a local surveyor to have a quick look if you can find one.

[carr]

Chala

Good points all. My last boat was a homebuilt and I had no problem insuring her, although she was aluminum.

As far as the observation on steel and cement or concrete existing together its obvious that they do everywhere, as you stated.I like you, have reservations, but mine are due to my own lack of experience with these materials.

Thanks very much for your interest. If I decide to pursue this vessel Im going to find a surveyor there to have a look before I go to the expense and time of going there.

Regards

Carr

[rolygate]

@Gordmay
Thanks for giving the links to my site there, Gord. I hope that's been of interest and use to people because it took a lot of sweat both to get the knowledge, and then to write it up. Fun though.

@Carr
The guys have said get a surveyor and that has to be right. If a fee of $500 or whatever saves you a wild goose chase, then it's money well spent, I reckon.

A note of caution though: I've had boats surveyed in other countries and there are some issues. The surveys were cheap, compared to the cost here in the UK, and the info was still as good. It varies from man to man of course, as is to be inspected. We figure a real surveyor is a guy who takes all day to do a boat, but there aren't many of them. I have a problem with the 3-hour guys. A 35' boat full survey is no 3 or 4-hour job.

But you need to ask yourself about just how independent the surveyor is. If he's looking at a privately-owned boat, with no boatyard involved, then there are no worries. But if by chance a boatyard or brokers are selling or involved somewhere - then there are going to be independence issues. You're going to buy and disappear over the horizon. The brokers give him work on a regular basis. Figure out where his real loyalties lie.

I say this because I've seen a real dog get a great survey when the buyer was going to sail away. Maybe it was because the surveyor was no good, maybe it was because his local main dealer were the sellers. Who knows.

Re. concrete and steel: I'm not in a position to contradict Bruce Roberts because he's the man. Him, vd Stadt, deGroot are the world-renowned experts on steel, to contradict them would be unwise. There's a valid argument that he has more boats on the water than any other single designer, as all the contenders for that are design offices, their work is actually a team job. I have huge respect for him, he has an unbeatable background.

But from the SMALL number of steel boats I've seen where the concrete was jack-hammered out by a new owner during the first refit, because of the worry over corrosion, and they turned out to be good as new underneath after 30 years or so, I'm happy with it if it's done the right way for the right reasons. I wouldn't new build that way, I see no reason to do it, but I guess there may be reasons to do it later. Maybe it's all in the way it's done.

I wouldn't be too worried about concrete in a sealed ballast chamber, for example. From personal knowledge I know this has been OK in several cases. But if things go wrong though - I guess that's a different story. Hit a rock, get water in, etc. I agree with BR anyway that a new boat shouldn't be built that way. And if he says that it's best avoided at all times - well then we should follow that advice.

For sure, the worst steel boats I've seen that rusted, had all rusted out from the inside. Anyone can see rust on the outside.

Re. insurance - what marinas normally need is proof of 3rd-party insurance. This is slightly different from your normal boat insurance. It's a whole lot cheaper, you can get it for about $150. They'll insure any boat, who built it is not an issue. It gives you a certificate that marinas will accept. There are a ton of issues here of course but it may be all you need / want. Obviously, you don't get a cent, whatever happens to your boat; the company may not stand behind it when the chips are down; it may cost more to get international coverage; etc. But it's a bit of paper and that's what you often need in this world, just to get on with your life.

[Steve Pope]

Cement has been used as a sealer in steel hulls for for as long as they have been built, It is commonly used to cement wash the inside of water tanks. I doubt that you would have a problem with it. Galvanised rigging is as strong as SS and doesn't have the fatal flaw of snapping with no warning, if it isn't maintained it will progressively deteriorate but will give you many signs that it needs replacing before breaking. It does require maintenance though, coating in boiled linseed oil is the preferred method. I have sailed on a ketch that had Galv rigging that was over 25 years old and it was as good as the day it was fitted, (well maintained) a fraction the price of SS. Spiral welded pipe masts takes me back to the days of home built Ferro yachts, it was quite popular amongst the more frugal builders here in NZ. Strong, ugly, but not that much heavier than the larger section that you would need if making an alluminium mast. I am in NZ so if you wanted you could pm me and if it was in my neck of the woods I maybe could check it out for you. On my alloy cutter I have lead ballast set in epoxy, the boat is over 30 years old so it seems to be OK.