MarsKeel™ has the ability to produce all lead keel castings ranging from 100 lbs to 200,000 lbs. These keel castings can take virtually any shape or size.

At MarsKeel™ we are a complete and comprehensive keel manufacturer. We produce every part your keel requires, from the pattern to the casting to any and all machined or fabricated parts. It is through this combination of disciplines; highly skilled people enable us to produce the world leading quality we can offer you. We do not just control every aspect of the process, we are constantly improving the process, pushing the technology of casting to ever higher levels. Our goal is to always strive to offer the customer a better product.

The production process begins with the creation of the pattern, generated from the customer supplied drawings. This drawing can be offered in the form of printed Mylars or CAD drawings. It is at this point that we apply the required core prints for the necessary casting fixtures. This allows us to cast any holes, recesses in the part. The fixtures are designed and fabricated or machined in house, based on the offered drawings. During the pattern process it is also decided if the keel can be cast from a solid pattern or a split pattern. It is at this point that the required amount of shrinkage is applied to the pattern. The shrinkage of cast lead is approx. 1% or 1/100” per inch. You can see other properties of keel lead, based on the anatomy level in the following chart.

Once the completed pattern is in the casting shop it is boxed, prepared for molding. We pour and cure our molds in house. We offer the use of our Ceramicast™ molding material or our AccuSand™ material. Our Ceramicast™ is generally used for large keels with limited details. Our AccuSand™ material is used generally for smaller castings with higher levels of detail. AccuSand™ offers you the highest density, but it is a more expensive molding material.

While the mold is curing we proceed with the design and production of the required bolt rack, and welded bolt cage. (If your design requires cast in keel bolts) The rack is a fabricated structure that holds the bolts in place from above the casting. It is removed after casting is complete. The rack, with the keel bolts is positioned on the mold, and then welded to the mold brackets.

The bolts themselves are positioned in the rack, with proper above lead heights, and then they are all connected together by rods welded from bolt to bolt below the lead line. This welded armature becomes part of the casting.  This is a welded armature is used to hold the keel bolts on station during the casting and cooling of the casting. The tolerance for the position of the keel bolts is approx. +/- 2mm. we have achieved this tolerance and better on castings well over 40,000 lbs. Lead inflicts a great deal of pressure on internal parts (keel bolts etc.) during the cooling caused by the shrinkage of the lead.

The bolts themselves can be made from a large range of materials such as,

A complete list of materials and their physical properties is available in the Custom Fasteners section of the web site.

Apart from just the keel bolts we have the ability to produce and locate virtually and kind of internal weldment or machined part in a lead casting. Any kind of internal part is be located by cores in the mold, they can be held with a consumable core, (used for the casting process only) consideration has to be made to keep lead out of unwanted areas. Great attention is paid to the alignment of any and all internal parts. This process is started with the mold open and finished by our staff going right inside the closed mold to ensure the parts are in the correct position before casting.

If your design requires the use of bolt holes and recesses we will design and produce all the required casting fixtures based on the customer offered drawings. This is all though through during the pattern making process. These casting fixtures range from fabricated core boxes to fully machined plunger rods. They are all designed and produced to ensure the highest possible casting definition and closest possible positioning.

When it comes to the casting, our casting floor has the ability to pour simultaneously from 2 furnaces into a single mold. This allows us to pour large casting quickly, removing the possibility of cold shots in the casting. This style of pour can be continued as long as necessary because the furnaces are recharged with lead throughout the casting period with no loss in temperature or necessity for stopping the pour. Our casting technicians are continually monitoring both the pour and the furnaces. In very large open top pours they continually flame the lead surface to keep it liquid, allowing for a uniformed casting. For closed top pours, bulbs, they keep the gates open and liquid. As the pouring is topped off and begins to cool the casting is continually topped up with lead and flamed to keep the top liquid. This process can continue for hours after the casting is completed. The longer you can keep the casting top liquid and topped up during the cooling process the less shrinkage you will get in the keel.

Depending on the size of the keel the complete cooling can take days. The mold and keel is left in place under the furnaces for up to two days, until the keel has cooled to a point that can be safely handled. At this point the brackets are removed from the mold. The bolt rack is them removed from the exposed keel bolts and handling fixtures are installed, in preparation for removal form the mold. Depending on the size of the mold and casting the opening of the mold and removal of the keel can take hours.

The finishing process begins as soon as the casting is removed from the mold. The next step is to remove any and all casting fixtures, core boxes or plunger rods. Once this is complete the finishing technicians begin with a rough ground to remove any casting scale. The finished surface is created by fairing the keel with epoxy or polyester based fillers. We offer a hand finish, +/- 2mm of the required surface or a High Grade Finish. The faired surface is the coated with Interprotect 2000E and sanded to offer a smooth and fair finish. The surface can be sanded to approx. 320 grit if required. Templates are created to assure accuracy of all our custom keels in the final fairing procedure.

Once the keel is completed, checked and accepted it is given to the shipping department. They will package, crate or skid the keel for the required transportation method to the customer, be it by road or ship. Our attention to detail goes from receipt of the drawings to delivery to the customer.