Why marine hardware costs more, why it matters, and what happens when you substitute standard hardware store products on a boat in the Florida Keys. Published by Key West Marine Hardware | Updated April 2026 818 Caroline Street, Key West, FL 33040 | (305) 294-3425 | kwmh.com
The Question Every Boater Asks. Eventually, it usually happens at a hardware store. You're holding a stainless steel bolt that costs $0.40,
and you know the marine version of the same bolt at the chandlery costs $2.10. Or you're looking at electrical wire that appears identical to marine wire but costs half as much. Or you find paint at a home improvement store that claims to be "exterior, moisture-resistant, UV-stable" — and you wonder if it's close enough. The answer, consistently, is no, and the reasons why are specific, technical, and worth understanding before you make a decision that costs you far more to fix than you saved buying the wrong product. This page explains the actual standards behind marine-grade materials: what they are, who sets them, and what physically happens when you substitute standard products in a saltwater environment. It also covers what makes the Florida Keys specifically one of the most demanding marine environments in the world, and why the hardware that holds up in Minnesota's freshwater lakes fails in Monroe County within months. The Florida Keys Environment — Why It's Different. Before discussing materials, it's worth establishing exactly what those materials are up against in Key West and the surrounding waters. Salt Concentration The waters surrounding the Florida Keys average salinity of approximately 36 parts per thousand, among the highest in any near-coastal boating environment in the United States. For comparison, the Great Lakes are freshwater. Chesapeake Bay averages 10–15 ppt. The Florida Keys are effectively open ocean. Salt is not only in the water — it is continuously airborne. Fine salt spray deposits on every surface, penetrates every unsealed joint, and wicks into every porous material by capillary action.
Humidity Key West averages approximately 75% relative humidity year-round, with summer months
regularly exceeding 85–90% RH. High humidity accelerates corrosion of ferrous metals, promotes galvanic action between dissimilar metals, and degrades adhesive bonds, sealants, and paint films. Humidity also feeds mold and biological growth on organic materials — teak, canvas, vinyl, and fiberglass gel coat. UV Radiation
Key West sits at approximately 24.5° north latitude — roughly the same latitude as Riyadh, Saudi Arabia. UV index regularly reaches 10–11 (extreme) from April through October. UV degrades polymer chains in plastics, rubbers, resins, and paint binders. Materials rated for UV stability in northern climates may have a service life measured in months in the Florida Keys, not years. Thermal Cycling
Surface temperatures on a boat deck in Key West can reach 150°F+ in direct summer sun and drop to 55°F on a January night. This 90–100°F daily thermal swing causes expansion and
contraction in all materials — stressing seals, cracking paints, loosening fasteners, and opening gaps that allow moisture intrusion. Galvanic Environment Salt water is an electrolyte. Whenever two dissimilar metals are in contact in salt water or in a salt-humid environment, they form a galvanic cell — one metal acts as the anode and corrodes preferentially. The Florida Keys' warm, high-salinity water is among the most aggressive galvanic environments in recreational boating. The difference in corrosion rate between a properly specified fastener and an incorrectly specified one can be a matter of weeks, not years. Marine Electrical Standards — ABYC and Why They Exist The American Boat and Yacht Council (ABYC) is the primary standards body for recreational marine electrical systems in the United States. ABYC standards are not federal law for recreational vessels, but they are the recognized industry standard for marine electrical work —Referenced by insurers, surveyors, and the USCG. Any vessel built or modified to ABYC standards is built to a defensible, consistent baseline of safety. The core ABYC electrical standard is E-11: AC and DC Electrical Systems on Boats. It covers wire sizing, insulation ratings, termination methods, overcurrent protection, grounding, and bonding. Understanding why E-11 specifies what it does explains why marine electrical
components cost more than their household counterparts. Tinned Copper Wire — Why It's Not Optional. This is the single most commonly misunderstood specification in marine electrical work. Standard automotive and household electrical wire uses bare copper conductors. Marine wire uses tinned copper conductors — individual strands of copper that have been electroplated with a thin layer of pure tin before being twisted into the conductor bundle and jacketed. The tin plating serves three functions in a marine environment: a corrosion barrier. Bare copper oxidizes rapidly in salt air. Copper oxide is a poor electrical
conductor — it increases resistance, generates heat, and can cause connection failures. Tin oxide (stannic oxide) is also a poor conductor, but tin oxidizes far more slowly than copper, and the oxide layer is self-limiting. In a marine environment, tinned wire maintains electrical integrity
for years, whereas bare copper wire begins to degrade within months.
Solder compatibility. Tinned conductors accept solder readily and form reliable joints. Oxidized bare copper resists solder, resulting in cold joints that fail under vibration. Identification. Tinned wire remains silver-gray in color even after exposure; oxidized bare copper turns green-black. In a wiring harness, you can identify a tinned wire at a glance — and identify an inappropriate substitution just as quickly. What happens when you use automotive wire on a boat in the Keys: In 12–18 months in a bilge environment or an engine compartment, bare copper conductors begin to green. The oxidation is worst at terminations — where the conductor is exposed inside a crimp lug or terminal. Resistance increases. The connection heats under load. In the best case, you lose a circuit. In the worst case, a high-resistance connection in a fuel pump circuit or ignition circuit generates enough heat to ignite fuel vapor. Boat fires in the Florida Keys are disproportionately electrical in origin — and disproportionately traced to non-marine wiring in high-humidity compartments. ABYC E-11 specification: Conductors shall be stranded, tinned copper per UL 1426 (Boat Cable) or UL 1072. Single-strand (solid) wire is not permitted in marine applications — vibration causes solid conductors to work-harden and fracture at terminations. Insulation Ratings — Temperature and Oil Resistance Marine wire insulation must meet two requirements that standard electrical wire does not: elevated temperature rating and resistance to oil, fuel, and water. ABYC E-11 requires insulation rated for a minimum of 105°C (221°F) in engine compartments and locations where ambient temperature can rise significantly. Standard residential and Automotive wire is typically rated for 60°C or 80°C — temperatures routinely exceeded in an enclosed engine compartment or a black-painted electrical panel in a Key West summer.
UL 1426 (Boat Cable) is the standard marine wire insulation specification. It covers:
● Temperature rating: 60°C in wet locations, 105°C in dry/hot locations (check wire rating
per application)
● Oil and fuel resistance — the insulation does not soften, crack, or absorb hydrocarbons
● Flame resistance — does not propagate flame per UL 94 HB standard
● UV stability — outer jacket resists UV degradation in exposed installations
UL 1072 (Marine Shipboard Cable) is a higher specification used in commercial and larger vessel applications. What to look for on wire packaging: Confirm the wire is labeled UL 1426, "BOAT CABLE," or "BC-5W2" (a common UL 1426 designation). If the packaging says "automotive," "household," or references any specification other than a marine standard, it is not the right wire for your vessel. Wire Gauge Sizing — ABYC Tables vs. NEC Tables Household and automotive wire sizing is determined by ampacity — the current-carrying capacity of the conductor. Marine wire sizing uses ABYC tables that account for both ampacity and voltage drop, which matters more in 12V DC systems than in 120V AC household circuits. In a 12V system, a 3% voltage drop — the ABYC maximum for most circuits — represents only 0.36 volts. Over a long run of undersized wire, that drop is enough to cause instruments to malfunction, bilge pumps to run slowly, and navigation lights to dim. The same 3% drop in a 120V household circuit is imperceptible. ABYC E-11 voltage drop rule: For critical systems (navigation lights, bilge pumps, electronics), maximum 3% voltage drop at full load. For non-critical loads, 10% is permitted but not recommended. Practical consequence: In many marine wiring applications, the correct wire gauge is one or two sizes larger than an automotive installer would specify for the same current load — because the run length and voltage constraints change the calculation. Terminals, Connectors, and Crimping Terminal quality and crimping technique are where most field marine electrical failures originate
— not in the wire itself. ABYC specifies:
● Heat-shrink adhesive-lined terminals for any connection exposed to moisture. The adhesive lining melts and flows around the conductor when heat is applied, creating a watertight seal. Standard vinyl-insulated crimp terminals do not seal — moisture wicks
into the barrel by capillary action and corrodes the connection from the inside.
● Ratchet crimping tools that apply consistent, calibrated crimp force. Plier-style crimpers produce inconsistent crimps — some too loose (pull-out failure), some too tight
(conductor fracture).
● No wire nuts. Wire nuts are prohibited in marine installations. They rely on thread engagement and friction that fails under vibration. A wire nut that has been vibrated loose in an engine compartment is an intermittent short waiting to happen.
● Ring terminals, not spade terminals, for any connection subject to vibration. Spade terminals can back out; ring terminals require positive removal.
Overcurrent Protection — Fuses and Circuit Breakers ABYC E-11 requires overcurrent protection (fuse or circuit breaker) as close to the power source as practicable — within 7 inches of the battery (or bus bar) for unprotected wire runs. This is stricter than automotive practice and far stricter than household wiring practice, where
Circuit breakers are at a central panel that may be 30+ feet from the source. The reason is fire suppression: in a marine environment, a short circuit in unprotected wire between the battery and a distant fuse can arc long enough to ignite insulation, bilge vapors, or
combustible material nearby. The shorter the unprotected run, the less opportunity for a fire to start before the overcurrent protection acts.

Panel-mounted breakers must be rated for DC voltage (not just AC), marine-grade, and corrosion-resistant. Standard residential circuit breakers are not rated for marine DC service and
should not be used as substitutes. Marine Hardware Standards — Stainless Steel Grades. "Stainless steel" is not a single material. It is a family of iron-chromium-nickel alloys, and the
difference between grades matters enormously in a saltwater environment. The two grades most commonly encountered by boaters are 304 and 316, and the difference between them — in a salt environment — can be the difference between hardware that lasts decades and hardware that is visibly rusting within a season. The Metallurgy — What Makes the Difference All stainless steels resist corrosion through the formation of a passive chromium oxide layer on the surface. When the surface is scratched or abraded, this layer self-repairs in the presence of oxygen — which is why stainless doesn't rust the way carbon steel does.
The difference between 304 and 316 is the addition of molybdenum in 316.
Property 304 Stainless 316 Stainless
Chromium content 18% 16–18%
Nickel content 8–10.5% 10–14%
Molybdenum content None 2–3%
Manganese content 2% max 2% max
Corrosion resistance (general) Good Excellent Chloride resistance Moderate High Pitting resistance (PREN) ~20 ~26
Typical cost premium Baseline 20–40%
Molybdenum is the critical addition. It dramatically improves resistance to pitting corrosion — the localized attack that occurs when chloride ions (the primary ion in salt water) penetrate the
passive oxide layer at surface defects. Without molybdenum, chloride ions can initiate pits that grow rapidly under the surface while the surrounding metal appears intact. Pitting is particularly
dangerous in structural applications — a fastener or fitting can look acceptable on the surface while its cross-section has been significantly reduced.
304 Stainless in a Marine Environment
304 stainless is appropriate for:

● Interior applications where the hardware is not exposed to salt spray, standing water,
or direct salt contact
● Fresh water environments (lakes, rivers, freshwater tanks)
● Occasional salt exposure — hardware that is rinsed regularly and inspected frequently 304 stainless is not appropriate for:
● Deck hardware in constant salt spray exposure
● Below-waterline applications of any kind
● Fasteners in fiberglass or aluminum where galvanic exposure is present
● Chainplates, stays, or any structural standing rigging component
● Through-hull fittings, sea cocks, or any fitting in contact with bilge water or seawater What happens to 304 in the Keys: In direct salt spray exposure with no rinsing regime, 304 stainless develops surface rust (tea staining) within 6–12 months. This is not structurally critical initially — it is the passive layer being compromised and the iron in the alloy beginning to
corrode. In humid, salt-laden bilge environments or on deck hardware that retains moisture in crevices (under washers, in threads), 304 can develop crevice corrosion and pitting within the
same timeframe. A 304 stainless deck screw used to fasten hardware in a teak cap rail on a Key West vessel may be structurally compromised within 18–24 months. 316 Stainless — The Marine Standard 316 stainless is the baseline specification for exposed marine hardware. Its molybdenum content provides sufficient resistance to pitting and crevice corrosion in salt spray environments for a service life measured in years to decades when properly maintained. 316L ("low carbon") is a variant with reduced carbon content that improves weldability without sensitization — relevant for welded fittings and custom fabrication. For hardware applications
(fasteners, deck fittings, cleats, blocks), standard 316 is appropriate. 316 stainless is appropriate for:
● All exposed deck hardware
● Fasteners in any application with salt exposure
● Handrails, stanchions, and lifeline hardware
● Anchor windlass components
● Electrical panel fasteners
● Below-deck hardware in humid or wet environments
316 stainless is still not appropriate for:
● Below-waterline primary structural applications (prefer naval brass or bronze for through-hulls)
● Applications with crevice corrosion conditions and no maintenance (316 can still pit in severe crevice conditions; it just takes much longer than 304)
● Any application where aluminum contact is possible without isolation
(stainless-aluminum galvanic coupling is aggressive) Other Hardware Metals — Bronze, Aluminum, and Brass

Naval Brass (C46400): An alloy of copper (60%), zinc (39%), and tin (1%). The tin addition suppresses dezincification — the leaching of zinc from brass alloys that can occur in salt water, leaving a porous, weakened copper sponge structure. Naval brass is the standard material for through-hull fittings, sea cocks, propeller shaft cutlass bearing housings, and underwater fittings. Unmistakably gold-colored. Manganese Bronze / Silicon Bronze: Higher-strength copper alloys used for propellers, shaft hardware, and structural underwater castings. Resist corrosion and biofouling better than
standard brass. Bronze fasteners (silicon bronze) are preferred for wood boat construction and for any application where wood contact causes corrosion in standard stainless. Marine-Grade Aluminum (5052, 5083, 6061-T6): Aluminum alloys with magnesium or magnesium-silicon additions that improve saltwater corrosion resistance. Marine-grade aluminum is not the same as standard aluminum — structural aluminum used in buildings, automotive trim, and consumer hardware is often 6061, 2024, or 7075, which are high strength but can corrode aggressively in salt environments. Marine aluminum must be specified by alloy number. Never use hardware-store aluminum fasteners or fittings in a marine application. Standard yellow brass (C26000 / cartridge brass): Common in plumbing fittings and hardware store products. Subject to dezincification in salt water. Identifiable by its bright yellow color. Do not use in marine applications exposed to salt water or high humidity. Marine Paint and Coating Systems Paint selection for a boat in Key West is not a matter of aesthetic preference — it is a functional
engineering decision. The wrong paint system fails rapidly and expensively, and failures in bottom paint or deck coatings allow water intrusion that causes structural osmotic blistering,
core delamination, and wood rot — damage that costs orders of magnitude more to repair than the paint savings.
Bottom Paint — Antifouling Systems
Bottom paint (antifouling paint) is the coating applied below the waterline to prevent biological growth — barnacles, slime, algae, and grass — on the hull. In the warm, nutrient-rich waters of In the Florida Keys, biofouling growth rates are among the highest in the U.S. A bare fiberglass hull left in Key West water without antifouling treatment can develop significant barnacle coverage within 2–4 weeks in summer. Ablative (self-polishing) antifouling paints: The paint film slowly erodes as the vessel moves through the water, continuously exposing fresh biocide at the surface. Ablative paints are preferred for vessels that are used regularly — the more the boat moves, the more the paint works. They do not build up excessively with recoats and tend to be easier to manage over time. Best for trailered boats and vessels with regular use. Hard antifouling paints: A fixed-film paint that releases biocide at a controlled rate without self-polishing. Harder surface is more abrasion-resistant — preferred for racing hulls, high-speed powerboats, and vessels that are hauled frequently. Builds up with successive coats and must be sanded back periodically.

Biocide types: Most modern antifouling paints use cuprous oxide (copper-based) biocide. Some use copper thiocyanate, zinc pyrithione, or combinations. Tin-based (tributyltin, TBT) paints have been globally banned. In Florida, copper content in antifouling paints is regulated in certain areas — confirm current regulations with the Florida DEP. Florida Keys-specific considerations:
● Bottom paint must be applied to a correctly prepared surface — fiberglass requires washing with a solvent wipe and barrier coat before antifouling. Skipping the barrier coat on a new or blistered hull invites osmotic moisture absorption.
● Copper-based antifouling paint is not compatible with aluminum hulls — copper accelerates galvanic corrosion of aluminum aggressively. Aluminum vessels require copper-free antifouling products.
● Annual haul-out and recoat is the standard practice for vessels kept in the water year-round in the Keys.
Topsides Paint — Above Waterline
Topsides paint is the finish coat on the hull above the waterline. In the Florida Keys, this paint must resist:
● UV exposure at tropical latitude intensity
● Salt spray and wash-down
● Thermal cycling
● Fuel and oil splash at the waterline
● Physical abrasion at dock contact points. Two-part polyurethane paints (Linear Polyurethane / LPU): The standard for high-performance topsides finishing. Products like Awlgrip, Interlux Perfection, and Toplac use an isocyanate hardener that cross-links the paint film into an extremely hard, chemically resistant, UV-stable surface. Two-part LPU is significantly harder, glossier, and more durable than one-part paints — but requires careful mixing, application skill, and adequate ventilation due to the isocyanate hazard during application. One-part polyurethane and alkyd paints: Easier to apply, less critical mixing requirements,
but shorter service life in UV and salt exposure. Appropriate for working boats, budget refinishes, and applications where annual recoat is part of the maintenance schedule. Gel coat: The original pigmented resin applied over the outer fiberglass laminate. Not a paint — a structural surface coat. Can be polished and maintained without repainting if the original surface is intact. Once gel coat is oxidized (chalky, dull), compounding and polishing can restore it temporarily, but paint is the durable long-term solution. Deck Paint and Non-Skid Systems Deck surfaces in Key West reach temperatures that can cause burns through bare feet in summer. They are continuously wet from spray, rain, and wash-down. They must provide reliable traction for the crew moving at sea. And they must hold up to UV exposure that degrades standard deck paints in 18–24 months.

Non-skid paint additives: Ground polymer beads or mineral aggregate (pumice, aluminum oxide) added to topside paint to create a textured, grip-promoting surface. Standard sand or
silica aggregate is too abrasive for comfort and can tear sails, lines, and soft goods. Marine-specific aggregate is calibrated for grip without excessive abrasion. Molded non-skid: The original factory-molded non-skid pattern in the gel coat. Can be maintained with appropriate non-skid cleaners. When refinishing, this pattern can be re-created with texture rollers or applied non-skid deck products like SeaDek or Teak. Below-Deck and Bilge Coatings
Bilge paint must resist:
● Standing water and bilge effluent
● Fuel and oil contamination
● Continuous high humidity
● Cleaning chemical exposure
Bilge paint (epoxy-based): Products like Bilgekote or equivalent epoxy-modified bilge paints are the standard. Epoxy provides water impermeability and chemical resistance that standard
paints cannot match. Must be applied to a clean, dry bilge surface — oil contamination prevents adhesion.
Do not use: Standard interior latex or enamel paint in a bilge. It will lift, blister, and peel within months in a Florida Keys bilge environment, creating debris that can clog bilge pump screens. Sealants — Why Marine Sealants Are Different
Sealants are as important as fasteners and hardware in a marine installation — and just as poorly understood by boaters accustomed to household products. The Three Types and Their Uses Polyurethane sealant (3M 5200, Sikaflex 291/292): The strongest marine sealant. Permanent or semi-permanent adhesive bond with excellent UV and salt water resistance. Use for through-deck fittings, hull-to-deck joints, and any application where permanent adhesive-sealing is required. Do not use where you ever intend to disassemble the joint — 5200 permanent is virtually impossible to remove without damaging the substrate. Silicone sealant: Not recommended for structural marine applications. Silicone does not adhere well to fiberglass and will not accept paint over it. Standard household silicone is completely inappropriate for marine use. Marine-grade silicone is available and appropriate for interior non-structural sealing, but it is not the choice for deck hardware or through-hull applications. Polysulfide sealant (Thiokol, Boat Life): Good chemical resistance, particularly to fuel. Appropriate for fuel tank fittings and applications where fuel contact is possible. Has lower strength than polyurethane but is more removable. Not compatible with all substrates — check compatibility before using on ABS plastic or some synthetics.

What Happens with Non-Marine Sealants Standard household caulk — acrylic latex, siliconized latex, or budget silicone — fails in a marine environment within one season in the Keys. UV breaks down the polymer chain, the
bead chalks and cracks, water intrusion begins, and the resulting moisture in the joint accelerates corrosion of any nearby hardware. A deck fitting bedded with hardware store caulk instead of marine polyurethane sealant will begin leaking within a year in Key West conditions. Why Hardware Store Products Fail on Boats — The
Summary Case The pattern is consistent across every category:
Product Hardware Store Version

Marine Version: Why It Fails Afloat
Electrical wire Bare copper, 60°C, vinyl
insulation Tinned copper, 105°C, UL 1426 Oxidizes at connections; insulation
softens in heat, Wire terminals, Vinyl crimp, no seal, Heat-shrink adhesive-lined, Moisture wicks in; corrodes from
inside Fasteners
(stainless) 304 stainless 316 stainless Pitting corrosion in chloride environment Fasteners
(brass) Yellow brass Naval brass or
silicon bronze Dezincification in salt water Sealant Acrylic latex or
silicone Polyurethane
marine sealant UV breakdown; adhesion failure on
fiberglass
Paint
(topside)
Exterior latex or
alkyd
Two-part LPU or
marine enamel
UV degradation; poor salt
resistance
Paint
(bottom)
None applicable Antifouling with
biocide
No biocide = barnacles in weeks
Paint (bilge) Interior latex Epoxy bilge paint Lifts and blisters in standing water
Wire
connectors

Household wire
nuts

Marine crimp
terminals

Vibration loosens; moisture enters

Lubricant WD-40,
petroleum grease

Lanolin, PTFE, or
marine-grade
grease

WD-40 displaces water briefly, then
evaporates; petroleum grease
washes out in water

Maintenance Practices That Extend Hardware Life in the Keys. The best hardware in the world degrades faster than it should without appropriate maintenance practices. For Key West conditions specifically: Rinse with fresh water after every use. Salt crystals left on hardware surfaces are hygroscopic — they absorb moisture from the air and maintain a continuous damp salt environment even when the boat is on a trailer or at a dry dock. A fresh water rinse after every trip removes deposited salt before it begins working. This single practice extends the service life
of deck hardware by years. Apply corrosion inhibitor to electrical connections. Products like Corrosion Block, Boeshield T-9, or CRC 6-56 (marine formulation) create a displacing film over electrical connections that
prevents moisture from establishing contact. Apply to terminal blocks, battery connections, and any exposed electrical connector annually or when connections are serviced. Inspect and re-bed deck hardware on a regular schedule. Even correctly installed hardware with proper marine sealant develops micro-cracks in the sealant bed over years of thermal cycling and mechanical loading. Deck core rot from water intrusion at hardware fittings is among the most common and expensive structural repairs on Florida Keys vessels. Pull, inspect, and re-bed deck hardware every 5–7 years as a standard maintenance item. Use sacrificial zinc anodes and inspect them. Zincs protect underwater metal by sacrificial corrosion — they corrode in preference to your propeller, shaft, and outdrive. In the high-salinity,
warm water of the Florida Keys, zincs deplete faster than in cooler northern waters. Inspect zincs every 3–4 months and replace at 50% depletion. A zinc that has been consumed entirely is providing no protection. Lubricate stainless steel threads before installation. Stainless steel fasteners are
susceptible to galling — a form of adhesive wear where stainless oxide layers on mating threads weld together under torque, making the fastener impossible to remove. Use an anti-seize compound (Tef-Gel, Lanocote, or equivalent) on stainless fastener threads before installation. This is particularly important for large-diameter fasteners and any application where
future disassembly is anticipated.
Where to Source Marine-Grade Materials in Key West Key West Marine Hardware 818 Caroline Street, Key West, FL 33040 (305) 294-3425 |
kwmh.com Hours: Monday–Saturday 8:00 AM – 5:30 PM | Sunday 9:00 AM – 3:00 PMWe stock marine-grade materials — not hardware store approximations — across all categories
described on this page. Electrical: UL 1426 tinned marine wire in all gauges, heat-shrink adhesive-lined terminals (ring, butt, spade), marine-rated circuit breakers and fuse holders, waterproof connectors, battery terminals, and marine wire management

Fasteners: 316 stainless in machine screws, lag screws, hex bolts, carriage bolts, U-bolts, and deck hardware fasteners; silicon bronze for wood applications; anti-seize compounds and
Tef-Gel Sealants and adhesives: 3M 5200 (permanent and fast-cure), Sikaflex 291, Boat Life polysulfide, marine-grade butyl tape for portlight and hatch installation Paint: Antifouling bottom paints (Interlux, Petit), Toplac and two-part polyurethane topsides.
bilge paint, non-skid additives
Hardware: 316 stainless cleats, fairleads, chocks, pad eyes, cam cleats, blocks, shackles, and deck hardware; naval bronze through-hull fittings and sea cocks; stainless wire rope and swage fittings Corrosion protection: Boeshield T-9, Corrosion Block, CRC 6-56 Marine, Lanocote, zinc anodes (shaft, hull, transom, outdrive — specify your application) If you're not sure whether a material is appropriate for your application — bring in what you're
replacing, or describe the application, and we'll specify the correct product. This is one of the most common conversations we have at the counter, and we'd rather spend five minutes
helping you buy the right part than have you come back in a season to deal with a failed installation. Frequently Asked Questions Is 316 stainless "marine-grade" on its own, or do I also need to worry about finish? Both matter. 316 is the correct alloy, but surface finish affects corrosion resistance. Polished stainless resists pitting better than brushed or rough-finished stainless because the passive layer reforms
more completely on a smooth surface. In crevice applications (under a washer, in a threaded hole), finish matters less than proper bedding and periodic maintenance. Can I mix 316 stainless and aluminum hardware on my boat? With caution. Stainless and aluminum in direct contact in a salt water environment form a galvanic couple that corrodes the aluminum preferentially — and aggressively. The standard practice is to isolate them with a barrier: nylon washers, Tef-Gel, or corrosion-resistant isolating tape. Aluminum boats require
particular attention to this — stainless hardware in direct contact with aluminum structure is a common cause of accelerated corrosion in aluminum-hulled vessels. Why is marine wire so much more expensive? The primary cost drivers are the tinning process (adds a manufacturing step), the quality of copper used (marine wire uses high-conductivity copper, not recycled-content alloys), and the more chemically resistant insulation compound. For a typical wiring project, the total wire cost difference between marine and automotive wire is modest — the cost of getting it wrong (corrosion, fire, a failed safety
circuit) is not. I see "marine-rated" products at big box stores. Is that the same? Sometimes, and sometimes not. The term "marine-rated" is not legally defined or regulated — it's a marketing
claim. The only way to verify is to check the specification: UL 1426 for wire, 316 alloy for stainless, ABYC E-11 compliance for electrical components. Ask for the spec, or ask us — we
can tell you if a product you're considering meets the standard.

What about WD-40 for corrosion protection on my boat? WD-40 is a water-displacing lubricant, not a corrosion inhibitor. It works briefly — minutes to hours — and then evaporates, leaving the surface no more protected than before. For marine corrosion protection on electrical
connections, use Corrosion Block or Boeshield T-9. For moving parts and hardware, use a marine-grade grease or Lanocote. WD-40 has legitimate uses on boats (loosening frozen fasteners, temporary moisture displacement) but is not a corrosion protection product.
This page is maintained by Key West Marine Hardware as a technical education resource for Florida Keys boaters, marine contractors, and vessel owners. ABYC standards referenced are
current as of April 2026 — consult current ABYC E-11 for the authoritative specification. This content does not constitute engineering or legal advice.
Key West Marine Hardware | 818 Caroline Street, Key West, FL 33040 | (305) 294-3425 | kwmh.com The Florida Keys' Full-Service Marine Chandlery