If you own a boat you’ve no doubt dealt with the nemesis of rusty, frozen or stuck hardware. It’s inevitable, anything made of ordinary carbon steel or iron aboard a vessel will, if not adequately protected, rust or seize. In some cases, even if it is protected, a galvanized anchor shackle for instance, it may still resist disassembly efforts after a few years of use.
Before delving into options for stuck, rusted or seized hardware, it’s worth spending a moment discussing methods for preventing this entirely avoidable scenario. It is unavoidable that where ordinary mild steel is concerned, if left uncoated or untreated, it will rust. Yet, we all too frequently ignore this fact until it’s too late.
Many, but not all, mild steel nuts and bolts are plated with cadmium or a chrome-based alloy to resist this natural onslaught. Plating quality plays a large role in how well it holds up to the elements, yet it’s tough to know how good any plating is simply by looking at it. High quality ferrous hydraulic fittings made by Parker for instance rely on a super tough plating process that holds up well in marine environment. However, if repeatedly sprayed or splashed with seawater this too will eventually begin to corrode. Play it safe and act early, all mild steel hardware should be preemptively painted or coated with corrosion inhibitor such as CRC Corporation’s Heavy Duty Corrosion Inhibitor. Ideally, such hardware should receive this treatment when new.
Consider using an anti-seize compound on select threads, particularly for galvanized shackles. Be warned, however, anti-seize will make fasteners more prone to self-loosening, which makes using a locking mechanism such as seizing wire, lock washers or nylock nuts is even more important. In my experience, some mechanics can get carried away with anti-seize, using it where it’s not called for, or using it where the a thread-locking agent would be more appropriate, such as motor mounts and shaft coupling bolts.
Fasteners that have been lubricated, with anti-seize or any lubricant for that matter, require a lower tightening torque, a detail that is noted on most torque charts as “wet” and “dry” torque ratings, the former are typically 15%-25% lower. Additionally, some anti-seize compounds utilize copper as the active agent; making them unsuitable for aluminum applications. Nickel-based anti-seize is preferred and ideal in all marine hardware applications.
An alternative for fasteners that aren’t routinely disassembled, involves the use of a thread-locking compound. This will serve two purposes, primarily it prevents fasteners from unscrewing themselves, and it excludes moisture from thread interfaces, thereby preventing corrosion and seizure. Where stainless fasteners are screwed into an aluminum substrate, an especially common, and particularly seizure prone scenario, aboard many vessels, simply excluding moisture from the interface is all that’s usually needed to prevent hardware from getting stuck. You can do this by using an expensive, proprietary compound designed for the application; however, I’ve had great success using simple polysulfide or polyurethane sealant, or a light duty thread-locking compound. Again, the primary goal is to exclude water or moisture from the interface.
Should you find yourself in a position of having to remove a badly rusted or seized fastener, you do have some weapons at your disposal. Scores of penetrating fluids exist and I’ve tried most of them, yet I keep returning to PB Blaster. The can’s gaudy label is a trademark, complete with the “As seen on TV” banner (I’ve never seen a TV ad for this product), yet it works and many of my mechanic colleagues swear by it. Keep a can aboard. As an aside, at least one independent test has a competing product, and my father’s perennial favorite (and the least expensive among proprietary penetrating oils), Liquid Wrench, edging out PB Blaster in effectiveness. In spite of that report I’m still loath to part with my can of PB.
Your next ally in this fight is heat. Heating a fastener, a nut for instance or substrate around a bolt will cause it to expand, often enough to loosen years’ worth if rust or corrosion and its grip. If you use a torch do so with extreme caution and make certain no flammable materials, rags soaked in penetrating oil for instance are nearby, or gasoline if you are working on or nearby an outboard motor, and keep a fire extinguisher handy. In some cases, selectively heating nuts or substrates and cooling bolts or studs can also be an effective approach. You can do so by placing an ice cube in contact with the stud, or even a damp cloth, after heating the nut.
008: Impact wrenches like the manual variety shown here are compact and inexpensive and effective. Pneumatic and electric varieties are also available, providing still more breaking energy.
Finally, if the stubborn fastener is a nut and it resists to the end, you can use a ‘Nut Cracker’, made by Craftsman. Nut Crackers rely on a hardened steel chisel like device that’s driven into and splits the nut. It surrounds the nut, into which the cutting blade is driven via a threaded mandrel. One way or another, there’s usually a way to remove frozen and rusted fasteners, provided you are equipped with the right tools. However, as the ‘ounce of prevention being worth a pound of cure’ axiom is especially relevant in this case, identify potential seizure and corrosion areas in advance, treat them accordingly, and you’ll save yourself untold aggravation, expense and equipment down time.