The Keel Specialists

The Canadian firm Mars Metal Company, a major producer of lead keels for , has expanded into other markets, including radiation and counterweights. Sou th ern Win d S h ipy a r

Text by Rob Mazza very large over iron in its higher density (and Edepends on ballast to provide sta- thus lower volume for a given Photographs courtesy Mars Metal bility to counter the heeling forces of weight) and its immunity to corro- (except where noted) its . After the introduction of fiber- sion. However, cast iron has two glass building and the success of important advantages over lead: the production-built Cal 40 (12.2m) higher mechanical properties and and custom-built Red Jacket in the substantially lower cost. For produc- 1960s, this ballast was most often cast tion builders, as we shall see, recent in the form of a separate airfoil-shaped fluctuations in metal prices, combined fin keel. The cast fin not only provides with an exceptionally challenging the required stability but also the market for production sailboats, have hydrodynamic lift necessary to allow tilted the advantage toward iron. the boat to go to windward without That shift has left traditional lead- slipping sideways (making leeway). keel manufacturers scrambling to Above—With her keel fitted, the 95' Since the advent of external ballast, redefine their market. (29m) Lady G, built by Southern Wind 35%–50% of the weight of nearly every Shipyard, in Cape Town, South Africa, large production sailboat has been in The Beginning is ready for launching. With so few the cast ballast keel. During the boom of the foundries interested in casting large The two popular choices of mate- 1960s and ’70s, when lead keels were lead objects, Mars Metal Company has rial for ballast keels are lead and provided by a number of local found- clients worldwide. iron. Lead has distinct advantages ries throughout the continent, Canada

2 Professional BoatBuilder Preparing a large open mold, fabricated in Cerami­cast tooling material, for a continuous lead pour. At 153,500 lbs (69,626 kg), the largest keel the company has cast to date was for the Bruce King–designed and Hodgdon-built 155' (47.2m) Scheherazade.

Metal in Toronto supplied most of the looking for a secondary source of Ready to Go cast lead keels to the 40-plus sailboat supply, Mars was soon getting small By providing production keels to builders in Ontario and Quebec. Then orders from CS , and even C&C O’Day, Mars Metal took a big step to dif- Mars Metal emerged in the adjacent Yachts. Soon it had all the keel busi- ferentiate itself from other suppliers. community of Burlington, Ontario, to ness from local builders. In the early Previously, the lead casting sent to the challenge, and then supplant, the and mid-1980s Mars made inroads boatbuilder was often very rough, with older foundries. However, the decline into the United States, supplying some flashing and grinding marks still visible in production sailboat construction keel castings to Hinckley Yachts, in on the surface. At C&C Yachts, for forced the company to become more , and to the O’Day Corporation, example, those keels were “faired” by versatile. It began supplying a better in Rhode Island. Then builder Andy further rough grinding during the night and more specialized product, and it Wiggers of Bowman­ville, Ontario, shift, and then primed and painted diversified into other industries. asked Mars Metal to build the cast while awaiting installation over the Today, its three divisions of lead prod­ lead keel for the Canada’s Cup defen­ next few days. Mars Metal set out to ucts include not only keels (MarsKeel der Coug I. When that Doug Peterson change that with a ready-to-install Technology, our focus here) but also design went on to successfully defend keel—faired, primed, and painted. counterweights for lift bridges (Mars­ the Canada’s Cup in 1981 in Hamil­ The initial coating was a clear ure- Metal Specialty Casting), and shielding ton, against the American challenger thane that the company had originally and containment devices for medical, Black Magic, Mars Metal gained applied to downrigger fishing nuclear, and border-security purposes standing in the custom one-off market weights. O’Day then asked that the (MarShield). as well. primer coat for the bottom paint also The Mars Metal Company began in 1979 when Philip Milne established a small 1,500-sq-ft (140m2) “one pot” lead foundry in the Burlington area, Working With Lead producing lead solder for the auto- motive industry, plumbing lead, fish- hen dealing with lead, the many environmental constraints include ing weights, and small ingots, all cast Wremaining within code, restricting and monitoring air emissions, and from melted lead scraps. giving employees regular blood tests. It is primarily for those reasons, as it wasn’t long before Mars Metal well as quality concerns, that MarsKeel uses only ingot lead, not scrap lead, was also casting the occasional lead for its castings. keel for the burgeoning sailboat The mechanical properties of lead can be greatly increased by adding industry at the western end of Lake antimony. The company inventories and orders lead ingots varying all the Ontario. Back then, there were more way from pure lead to the required antimony content, which for keels is in than a dozen sailboat builders within the 2%–4% range, depending on the physical properties required. All of an easy one-hour drive of the plant, this, of course, drives up prices, but creates a much more comfortable and noted Kevin Milne, Philip’s son and environmentally friendly work environment, and a much more consistent now owner and president. The com- product. The addition of antimony has an incremental effect on density, but pany’s credibility in that market a 4% addition will increase strength threefold and hardness by 2.5, with a increased with its first “large” cus- still-high 22% elongation, down from 80% for pure lead. tomer, Hughes Boatworks near Lon­ —Rob Mazza don, Ontario. With all boatbuilders

August/September 2015 3 Precision and care are required in lowering Lady G’s onto its 38,500-lb (17,463-kg) keel.

molds the cast surface is con- tinually “flamed” with a pro- pane torch to keep the lead liquid to ensure a uniform casting. For closed molds, such as bulbs, pouring gates are kept open and liquid. Even after the pour begins to cool, the casting is continu- ally “topped up,” and the open surface is flamed to maintain a liquid . This can take hours but reduces R o b M a zz shrinkage during cooling. For larger keels, complete cooling be applied over the initial coating. For the company employs its Ceramicast of the final casting can take several a while, some keels were even sup- molding material for high-volume days. Thus the filled mold is often left plied with bottom paint over the productions (usually large keels with under the furnace for up to two days primer, so the keel could be the last limited details), while it prefers until it is cool enough to be safely thing installed as the boat went out AccuSand, which incorporates tradi- handled. At that point, the bolt-mount- the door. Soon the company was fair- tional sand-casting technology, for ing hardware is removed, and the han- ing the keels with thickened WEST smaller castings with higher levels of dling fixtures are installed to support System epoxy or ATC Poly-Fair (now detail, making it more expensive. the weight of the casting as the mold produced by Scott Bader-ATC), under For both methods, size is not a is dismantled and removed. The sur- the sealer and primer coats. For C&C problem. In-house, MarsKeel can trans­ face is coated with two layers of Inter­ Yachts’ higher-performance , fer up to 200,000 lbs (90,680 kg) of Protect epoxy, then faired, sanded to Mars went further by clamping fiber- lead in a single pour. Its largest casting #320 grit if required, and coated with glass molds around the cast ballast to date, and the largest single-pour several more layers of epoxy. For cus- keel, into which it poured thickened lead casting in North America, accord- tom-cast lead keels, full-size templates epoxy to fill the thin space between ing to the company, was the 153,500- are also produced to assure accuracy. the lead and the mold, creating per- lb (69,626-kg) keel supplied to fectly fair and accurate shapes ready Hodgdon Yachts in Maine in 2000 for Through the Lean Years for priming and painting. the 155' (47.2m) Bruce King–designed in some cases, MarsKeel utilizes a According to the company website, Scheherazade. It was achieved by customer’s own permanent tooling. for production keels today, MarsKeel pouring from two furnaces simultane- For a number of prominent sailboat receives the keel drawing from the ously into a single mold. A pour can builders—including Catalina, Hunter, designer or builder, fabricates the continue indefinitely, as the furnaces Bénéteau, C&C, Tartan, and J Boats— wooden pattern approximately 1% are recharged with lead during the the company has in inventory more oversize (to account for shrinkage of casting, with no loss in temperature than 100 keel molds, either built by the lead as it cools), and then chooses and no interruption. In large open MarsKeel or supplied by the builder. the mold medium that In 2009, for instance, when Catalina best suits the antici- Yachts closed its longtime California pated production vol- operation to concentrate production umes. For tooling, in its Florida facility, it shipped all its Milne explained that permanent keel molds to MarsKeel. Prior to that, Catalina cast its own lead keels in California. MarsKeel still has all the Catalina keel molds in stor- A crew member age and often supplies replacement removes clamping keels to aftermarket boats. This ser- bolts from a multi- vice is of particular value to a boat piece permanent steel owner who wants to switch from a mold for a large shoal- standard deep-draft keel to an draft wing keel. Note optional shoal-draft keel; the com- that the keelbolts are pany may well have the mold for the cast in place. shoal keel in stock.

4 Professional BoatBuilder even though this was large-volume its success with J Boats led MarsKeel­ to promote the company’s interests in business, the margins, as with most to cast keels for a number of other TPI Europe. While Mars­Keel had displayed builders this size, were “cut throat,” models, such as the Alerion line, and to at the gigantic Marine Equipment admits Milne. Then it got worse. employ ICB keels on some of Morris Trade Show (METS), in Amsterdam, for MarsKeel was also supplying keels to Yachts’ higher-performance boats. several years, in 2013 Milne decided to Florida-based Hunter Marine (now display instead at the Monte Carlo Marlow-Hunter), but all business with Scaling Up Show. He felt that this was much Hunter, and a number of other pro- As the production-boat market was closer to MarsKeel’s desired market, duction builders, ground to a halt after faltering, the custom-superyacht market and the show produced a number of the 2008 recession, which devastated the was not, especially in Europe. Real­­ good contacts and brought the com- boating industry, especially the - izing this, Milne hired Willem Vraets, pany increased visibility in European boat segment. The lead-keel business based in Amsterdam, The Nether­lands, markets. was further hurt by the huge increase in commodity prices at the time. When lead jumped from 80¢ per lb to $1.50 per lb, it raised the price of a deliv- ered keel to over $2.50 per lb. With cast-iron keels being delivered at about 80¢ per lb, a number of sailboat builders were forced to retool their keels and switch to lower-density, greater-volume iron, which could potentially save over $10,000 per boat. Although this was a blow to MarsKeel, it had already taken steps to diversify. The company had made itself indis- pensible to the production sailboat market by supplying keels that were ready to install. However, to serve the expanding one-design market, espe- cially companies like J Boats (at the time being built by TPI), Mars devel- oped the ICB, or integral cast bulb, keel. It is formed by attaching an inte- grated triangular flat-bottom lead bulb to the bottom of a cast or welded structural­ airfoil-shaped fin. This low- ers the center of gravity of the ballast as much as possible, and greatly increases sailing stability. initially, the company produced fins from solid nickel-aluminum-bronze (NAB) alloy C95500, chosen for its light weight, strength, and resistance to corrosion. NAB fins were sus- pended over, and extended into, the split mold for the lead bulb. The lead was poured into the mold, locking the bulb onto the fin without requiring fasteners (see the Rovings item “Thin Is Beautiful,” PBB No. 54, page 22; and “Keels and : Engin­eering and Con­struction,” PBB No. 96). Recessing at the intersection of the cast bulb and the fin allowed the addi- tion of epoxy-laminated Kevlar tabbing to prevent thermal cracks at the joint. This process was originally used on the J/90 (32'/9.2m), and then the larger J/125 (41'/12.5m), and J/145 (48'/14.7m). It is still used on the J/111 (32'/9.2m), but with a welded stainless steel fin instead of the NAB cast alloy.

August/September 2015 5 Cast-lead production sailboat keels await shipping. With a combination of low center of gravity—achieved with the use of a triangular bulb—and elliptical plan- forms for reduced drag, the modern sail- boat keel has become a complex and sculptured appendage.

As boats continue to increase in size, they require reduced draft to allow their access to common cruising grounds and harbors. A shoal-draft fixed keel, like the 153,500-lb speci- men cast for Scheherazade, reduces draft, but can also compromise sailing performance. That’s because it’s nec- About eight years ago, the com- load of the fin and ballast on the hull essarily heavier, and it has less hydro- pany started casting keels for Southern itself, are considerable. Both must be dynamic efficiency. To fix this, pow- Winds Shipyard in Cape Town, South well understood and well engineered. erful hydraulic mechanisms with solid Africa, beginning with a 50,000-lb To provide such advanced design material bearings can lift the keel into (22,670-kg) bulb and fin for the Farr- and engineering services, the com- the hull, but that introduces some designed SW 100 RS (99'/30.2m). pany worked with two other firms to challenging design requirements, as Proj­ects for Southern Winds Shipyard create the MarsKeel Group. Mars­ the ballast keel transitions from a now range from 82' to 120' (25m to Keel’s Bill Souter, who is in charge of static element to a dynamic element. 37m), with boat designs by Farr and technical keel sales and design, con- In addition to the commonly accepted Reichel/ Pugh. Their keels are cast- sults with experts Dave Fornaro, of hydraulic systems, MarsKeel has eval- lead torpedo-shaped bulbs on welded- Ariston Technologies, and Steve uated ball screw jack systems. While steel fins. In this way, the bulk of the Burke, of Burke Design. (Keel shape, they have more than enough power weight is kept as low as possible to weights, and center of gravity loca- to lift the weights involved, achieving provide sailing stability in the form tions are designated by the specific the speed required to lift these mas- of a streamlined bulb, and the fin design office involved). Fornaro pro- sive keels is challenging. becomes a structural cantilevered beam vides structural and design services To simplify the installation of the in bending to support the lead as the on complex keels, and he will pro- many components involved in a lift- boat heels. At the same time, the air- duce the working drawings with all ing keel, MarsKeel has developed a -shaped fin generates the required the weld details required to build the cassette system in which the entire hydro­­dynamic lift on the high-aspect- keel, especially the welded-steel fin. assembly is housed in its own struc- ratio fin, the bulb providing an end- He often accompanies MarsKeel per- tural box and is attached to a mating plate effect to increase the lift/drag sonnel on trips to Europe to meet structure in the boat. This again is a ratio and foil efficiency. The loading at with potential superyacht customers logical extension of the ready-to- the root of this fin as it attaches to the and builders. Burke is brought into install philosophy established when hull, and the concentrated bending projects for composites engineering. the company was founded.

Final keel assembly of ballast, trim tab, and wings for the New Zealand 12-Meter NZ-7 Kiwi Magic, designed by Bruce Farr. The first 12-Meter built of fiber- glass, she lost to Stars & Stripes 87 in the Louis Vuitton Cup for the right to challenge defending champion Kookaburra III for the America’s Cup.

6 Professional BoatBuilder MarsKeel has access to this CNC router with a 60' x 20' (18.3m x 6.1m) table. Shown here, a welded steel fin for a retractable keel is machined.

the finished assembly cannot fit in a container, provisions must be made to it by whatever means suits the project. Keels are designed as precise air- foils to achieve the optimum lift/drag ratios, so they must be accurately machined to the final shape from IGES files supplied by the design engineer. In addition to its own CNC For projects this complex, MarsKeel ing, on average, approximately 5% of router, the company has access to a is usually involved early in the design the cost of the total project. large CNC mill, which has a maximum phase, although, in reality, the fabri- MarsKeel finds that itsN orth Amer­ horizontal boring mill with a 60' x 20' cation and final keel design are often ican location is not an impediment to (18.3m x 6.1m) table and a lifting later areas of design; that’s because being competitive in the European capacity of 60 tons. The machined the final ballast weight may well be market. Indeed, if the keel and bulb, finished surface usually offered has influenced by the recorded weight of properly supported, can be loaded scallop depths of 0.005" (0.13mm). the boat as it is being built. This engi- into an open-top container, shipping Although more time in the mill will neering work, if supplied by the costs and logistics are seldom a prob- produce a mirrorlike finish, a mini- MarsKeel Group, usually appears as a lem. Shipping considerations may mum amount of surface “roughness” line item on the final invoice, with the well determine if the bulb is integrally is required to achieve proper primer final cost of the keel itself represent- cast to the fin or bolted in place. If and paint adhesion.

8 Professional BoatBuilder While the bulb is always a lead At MarsKeel, a technician examines a casting, the fin can be produced in a machined, faired, and epoxy-coated steel variety of materials and by different fin to ensure that it’s ready for the bolt- methods. Perhaps the simplest is tra- on bulb. ditional cast iron with a lead shoe bolted in place for standard shoal- to moderate-draft boats. For higher- performance vessels with deeper bead-blasted, primed, and coated with draft and lighter displacement, the two layers of InterProtect 2000 epoxy choices include a fin cast in NAB; a before sanding, final fairing, and the fin welded from mild steel plate and application of several more layers of sheet; a fin from 316L or Duplex 2205 epoxy. They are then either dry- or stainless steel; or one that is produced wet-sanded to a final 320-grit surface. with A514 or CHT-100 high-strength The keelbolts for fastening the fin steel plate. MarsKeel has produced to the hull—or the bulb to the fin— fin-keel combinations from a 400-lb are also made in a wide range of (181-kg) stainless steel fin supporting materials. The choices include basic a 1,100-lb (499-kg) bulb, up to a 304 and 316 stainless steel, Duplex 7,650-lb (3,470-kg) welded mild-steel 2205 stainless steel, C95500 NAB, and fin supporting a 61,200-lb (27,760-kg) Aqualoy 22. lead bulb. The internal structure of these welded fins can get compli- Draft Reduction cated, especially if designed for The decline in production sailboat hydraulic lifting. Like the NAB-cast building means that many sailboats fins, the welded fins, too, can be designed with deep draft for race per- CNC-faired, as long as additional skin- formance are now almost exclusively plate thickness is specified to account used for cruising or club racing. Most for the removal of some material. of these past racers had drafts in the Like cast fins, the welded fins are 6'–8' (1.8m–2.4m) range, which makes

August/September 2015 9 it difficult for the boats to access a lot of cruising grounds, especially on the Great Lakes, where water levels have dropped dramatically in recent years. MarsKeel offers a fix to this problem with its draft-reduction service. For about $6,000 the company supplies a bolt-on two-piece bulb that attaches to the sides of a shortened keel; the retrofit achieves sailing stability com- parable to that of the original deep- draft keel. MarsKeel works with the boat owner and the yard doing the work to determine how much keel should be cut off and the weight of Left—The company offers a draft-reduction service that advises how much this deep- the required bulb, chosen from a draft iron keel is to be shortened to allow the boat’s access to shallower water. number of existing split-bulb molds. Right—Sailing stability is restored with a MarsKeel bolt-on split lead bulb, installed In the 20 years since this service has by the yard doing the retrofit. been offered, Milne figures the com- pany has provided over $1 million worth of bolt-on bulbs. looking installation. In all cases, the and washers, for quick installation by Bulbs can also be added to iron yard or owner supplies a horizontal the yard. keels, but while lead can be cut with template of the keel in way of the Mars also does a lot of insurance a chainsaw, shortening iron requires bulb, so Mars can incorporate the work on bent and damaged keels sent more advanced technology. In some appropriate curvature into the mating to the company by repair yards. cases, the bulb can be designed to surfaces of the split bulb for a tighter These repairs often involve keelbolt extend of the trailing edge of the fit to the fin. The bulbs come pre- removal and replacement. In some keel, which not only allows for a drilled and countersunk for the 316 cases, a new keel can be cast using larger bulb but also results in a cleaner- stainless steel threaded rods and nuts, existing inventoried tooling.

10 Professional BoatBuilder Out of the Water In addition to the Because lead is one of the densest large CNC mill materials on the planet, it offers excel- shown on page xx, lent protection and containment for MarsKeel employs radiation and X-rays. As part of its this in-house CNC diversification, Mars Metal has turned router for machining to lead shielding for radiation in med- versatility in its cast- ical and nuclear applications. Growth ing operations. in these markets now accounts for almost 70% of its annual sales. The MarShield line of containment prod- ucts includes a wide range of lead- lined stainless steel storage cabinets for radioactive materials, while shield- ing products include lead screens, walls, bricks, and barriers. With the rising number of X-ray inspections of weights. This division also distributes many other companies, has found trucks and containers by customs and lead shot and sheet lead, and pro- other markets that have allowed it to immigration agencies at national bor- duces lead ingots. prosper during the cyclic ups and ders, the company has seen increased Mars Metal has updated its lead- downs of the sailboat industry. sales of its lead brick and lead sheet manufacturing capabilities with the products. Because this is a distinctly recent addition of an in-house CNC About the Author: Rob Mazza is a different market, the MarShield divi- router for precision machining lead naval architect and professional engi- sion has its own specialized sales and components (which most companies neer with a long background with marketing arm for these products. are reluctant to handle) and produc- C&C Yachts, Mark Ellis Design, and in addition to MarsKeel Technology ing patterns in wood and high-density Hunter Marine. He has recently been and MarShield, the Specialty Casting foam. involved with structural core materials division produces lift-bridge counter- While it remains committed to the with ATC Chemicals (Corecell) and weights and mine shaft elevator marine industry, Mars Metal, like Baltek.

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