Caldwell Casting/Performance Metals R3750Z 3-3/4" Rudder/Trim Tab Zinc Anode

Caldwell Casting/Performance Metals

<h3>About Performance Metals / Caldwell Casting</h3><p>Performance Metals, manufactured by Caldwell Casting Co., is one of the marine industry's most respected names in sacrificial anode technology. <strong>Based in Cambridge, Maryland</strong>, the operation is a true American manufacturer: every anode is cast and assembled on-site at the Caldwell Casting facility, giving the brand tight control over material quality and consistency from raw alloy to finished product.</p><p>The brand is best known for its proprietary <strong>Navalloy&reg;</strong> aluminum anode alloy — a formulation built to U.S. military specification MIL-DTL-24779B(SH). Unlike traditional zinc anodes, which can passivate and stop working in freshwater or brackish conditions, Navalloy&reg; remains electrochemically active across all water types: saltwater, brackish, and fresh. It also carries a higher protection voltage than zinc and, by the brand's own testing, lasts up to 30–50% longer — all while containing only about 5% zinc compared to the 99.9% zinc found in conventional anodes. Environmental agencies have flagged pure zinc as a significant source of marina pollution, making aluminum-alloy alternatives an increasingly important choice for conscientious boaters.</p><p>One of Performance Metals' standout innovations is the exclusive <strong>Red Spot Wear Indicator</strong> — a colored plastic indicator embedded within each anode that becomes visible on the surface when the anode has worn to half its original size. This simple visual cue removes the guesswork from anode inspection, helping boat owners replace anodes at exactly the right time rather than too early or too late.</p><p>The team at Caldwell Casting brings decades of experience in casting, machining, and marine corrosion science. Their professionals approach every customer need as a problem-solving exercise, drawing on deep metallurgical knowledge to deliver cost-effective, application-specific solutions — whether for a weekend runabout or a large offshore yacht.</p><p>For boaters looking to protect their underwater metals from galvanic corrosion, Performance Metals offers two core product lines. Their <a href="/13337-caldwell-castingperformance-metals-anodeszincs-200103">individual anodes and zincs</a> cover a wide range of hull, shaft, prop, and engine applications for virtually every major outboard and sterndrive brand. For those servicing outdrives or complete systems, their convenient <a href="/13337-caldwell-castingperformance-metals-anode-kits-200102">anode kits</a> bundle everything needed for a full replacement in one attractively packaged set — complete with multilingual installation instructions. Both lines are manufactured from the same Navalloy&reg; alloy and meet or exceed ABYC cathodic protection standards.</p><h3>Why Choose Performance Metals?</h3><ul style="list-style:disc"><li>All anodes cast and assembled in-house in Cambridge, Maryland, USA</li><li>Navalloy&reg; alloy meets military specification MIL-DTL-24779B(SH)</li><li>Works in salt, brackish, <em>and</em> freshwater — unlike traditional zinc</li><li>Patented Red Spot Wear Indicator for easy visual inspection</li><li>Lasts up to 30–50% longer than comparable zinc anodes</li><li>Cadmium-free and low-zinc formula — a cleaner choice for marina environments</li><li>Kits include multilingual instructions for straightforward DIY installation</li></ul>