If we're relying on AI. Here is the ChatGPT answer using the Deep Dive function so it did about 10 minutes of research before generating the answer.
Question I asked:
Is crimping or soldering better for extending a 6 awg trolling motor wire with 60 amp circuit breaker? The wire will be run along the gunwall on the deck of the boat.
ChatGPT 4o Deep Research Report:
Crimping vs. Soldering for Extending a 6 AWG Marine Wire
Introduction
Extending a trolling motor’s 6 AWG power cable (feeding a 60 amp circuit breaker) requires a robust, low-resistance connection that can withstand harsh marine conditions. The wire will run along the gunwale on the deck – an area exposed to vibration, moisture, and possibly salt spray. Two common methods for splicing heavy-gauge wires are crimping (using a butt splice connector) and soldering the joint. This report examines the pros and cons of crimping versus soldering for this specific marine application. Key factors include electrical performance, corrosion resistance, mechanical durability under vibration, and ease of installation. We also consider marine safety standards (like ABYC guidelines) and expert recommendations. A summary comparison table is provided, followed by a recommendation for the best approach in this scenario.
Electrical Performance
Crimped connections – when done properly – provide excellent electrical performance for high-current marine wiring. A quality crimp effectively “cold-welds” the wire to the connector, creating a gas-tight metal-to-metal bond with very low resistance . In fact, crimp terminals have been used for decades in critical applications (from automobiles to aircraft and warships) as a proven method for making low-resistance connections without solder . The crimp compresses the strands tightly, which breaks down surface oxides and ensures maximum contact area. As long as the correct size connector and a proper crimp tool are used, the result is a reliable, high-conductivity joint that can handle 60 A current with minimal voltage drop. By contrast, soldered connections can also be electrically sound if executed perfectly – solder itself is a good conductor and can create a solid bond between wires. However, soldering does not guarantee a low-resistance joint unless the technique is flawless. A common pitfall is the “cold solder” joint, where insufficient heat or poor solder flow leaves flux or gaps in the joint, causing high resistance . Such defects may not be immediately obvious but can lead to voltage drop, heating, or intermittent performance under heavy loads. Additionally, unlike a crimp which inherently forms a tight mechanical contact, a solder-only splice relies entirely on the solder for conductivity; if any part of that solder joint degrades, electrical performance suffers. In practice, marine experts assert that a properly crimped connection is equal or superior to solder in conductivity for DC wiring . For a trolling motor’s power cable, where stable voltage and current flow are critical, the consistency of a crimp is a safer bet. It’s telling that American Boat & Yacht Council (ABYC) standards prohibit solder as the sole means of connection, underscoring that a crimp or other mechanical fastening is the primary method to ensure a sound electrical and mechanical link . Overall, while both methods can theoretically yield low resistance, crimping provides more consistent electrical performance in the field, with less risk of hidden flaws.
Corrosion Resistance
Marine environments are notoriously corrosive due to moisture (often saltwater) and temperature swings. Crimped splices, if done with marine-grade materials, offer excellent corrosion resistance. High-quality marine crimp connectors are made of tinned copper, which resists corrosion, and often come with insulating sleeves that are nylon or polyolefin heat-shrink. When a crimped butt connector is sealed with adhesive-lined heat shrink tubing, it creates a waterproof barrier that keeps out salt and moisture . The result is a gas-tight, sealed connection – the crimping action itself makes the joint air-tight, and the adhesive heat shrink provides an extra layer of protection against water ingress and “green” copper oxidation . Many marine electricians also apply dielectric grease or corrosion-inhibiting spray on the crimp before shrinking for additional protection . In short, a properly executed crimp with tinned conductors and sealed insulation can survive for decades without significant corrosion.
Soldered joints, on the other hand, require more care to be made corrosion-resistant. The solder itself (typically a tin-lead or tin-silver alloy) is somewhat resistant to oxidation, but the process of soldering introduces flux – and any flux residues or voids can become a site for corrosion. If acid flux is used (never recommended for electrical work) it will definitelycause copper corrosion; even normal rosin flux, if not fully cleaned, can attract moisture or create mildly acidic residues over time . Moreover, solder tends to wick into the wire strands beyond the joint, under the insulation. If the joint is not perfectly sealed, moisture can creep along the soldered strands, leading to hidden corrosion further up the wire. A soldered splice must therefore be thoroughly sealed with heat-shrink tubing or self-fusing tape to keep out moisture. However, achieving a waterproof seal can be trickier because the soldered section is often irregular in shape and the process of soldering may have shrunk back some insulation. Some installers will coat a soldered connection in liquid electrical tape or epoxy-lined heat shrink to try to exclude water. Despite these measures, many experts warn that soldered connections are more prone to develop the “black wire” or verdigris corrosion over time if any gap in the seal occurs . Crimped joints inherently have less wicking of solder (since none is used) and usually a shorter exposed area, so they present less opportunity for capillary water intrusion. In summary, while both methods can be made corrosion-resistant with proper sealing, crimping with tinned materials and adhesive heat shrink is simpler and more foolproof. Soldered splices carry a higher risk if not meticulously sealed, and any mistake in sealing can lead to creeping corrosion that compromises the connection. For a wire run along a boat’s deck (gunwale), which will see occasional spray and humidity, the safer choice is a well-sealed crimp joint.
Mechanical Durability
Mechanical durability is often the decisive factor in the crimp vs. solder debate for marine use. Boats endure constant vibration from engines and waves, as well as flexing and movement of cables as the vessel moves. In this regard, crimped connections are far more robust. A proper crimp joint maintains the flexibility of the stranded wire right up to the edge of the connector. The strands are cold-welded inside the crimp barrel but immediately outside that barrel the wire remains flexible. This means the transition from stiff connector to flexible wire is very short and well-contained. Under vibration, a good crimp essentially moves with the wire – there is no extended “hard” section to concentrate stress. Pull-out strength of a correctly crimped 6 AWG butt splice is very high (meeting UL and MIL-spec tensile tests), so the wire is unlikely to pull out of the connector if crimped with the right tool . In contrast, soldering creates a hard, rigid section of wirewhere the solder wicks into the strands. The once-stranded wire becomes a solid rod for some distance past the joint. This “hard spot” is a known point of weakness – vibration and flex tend to concentrate at the boundary between the soldered (stiff) part and the still-stranded (flexible) part of the wire. Over time, flexing at this boundary can cause the copper strands to fatigue and break. As one marine wiring expert bluntly summarizes: “Solder creates a brittle point and will fail before a proper crimp every time” . Indeed, ABYC’s rationale for discouraging solder-only connections is precisely the risk of vibration-induced failure. ABYC Standard E-11 states: “Solder shall not be the sole means of mechanical connection in any circuit.” If solder is used, the connection must be “supported to withstand vibration” – meaning the joint should be secured so it cannot move . This is difficult to guarantee in practice. A soldered splice in a wire run along the gunwale would need to be strapped down tightly on both sides of the joint to prevent any flex at the joint. Even then, the stress riser still exists. By comparison, a crimped butt splice with strain relief is already mechanically stable and can further be secured with clamps, making it highly vibration-resistant without special precautions.
Another aspect of mechanical durability is how the connection behaves under extreme conditions, like an overload or high heat. If a heavy current overload or fault were to occur (for example, a short that briefly exceeds 60 A before the breaker trips), a soldered joint could potentially heat up to the solder’s melting point, especially if it had any pre-existing high resistance. Standard 60/40 solder melts around ~188 °C. In a worst-case scenario, a soldered splice could re-melt and come apart under severe overheating. As one boating forum member noted, “Over-current situations can cause solder to melt… you have the potential for a live wire flopping around that could start your boat burning” . While such extremes are hopefully rare (the circuit breaker should protect against sustained overloads), it’s an added failure mode to consider. A crimped connection has no such melting point concerns – the copper will handle very high temperatures (well beyond any safe level for surrounding insulation) without the connection itself failing.
In summary, crimping wins decisively on mechanical durability for marine wiring. It produces a strong, vibration-proof joint that retains wire flexibility, whereas soldering introduces a brittle segment prone to failure unless the joint is perfectly supported (and even then, the margin for error is slim). This is reflected in industry practice: marine and aviation technicians overwhelmingly use crimp or bolt connections, not solder, for wire splices due to the superior resilience .
Ease of Installation
When it comes to practical installation on a boat, crimping is generally faster and more straightforward, provided the proper tools are at hand. To crimp a 6 AWG cable splice, one needs an appropriately sized butt connector and a heavy-duty crimp tool. For large gauge wires, this typically means a ratcheting lug crimper, hydraulic crimper, or at least a hammer crimp tool, since the common hand crimpers for small terminals won’t handle 6 AWG . Acquiring or borrowing a good crimp tool is a one-time effort, and many marine supply stores offer crimping services or tool loans (West Marine, for example, often lets customers use their heavy crimper for battery lugs in-store ). Once you have the right tool, the process is quick: strip the wire, insert it into the butt splice, and compress the crimp until it’s fully tight. A properly crimped connector will hold the wire so firmly that you cannot pull it out by hand . After crimping, you simply heat the insulating tube to seal it. No curing time, no cleanup. The result is immediately strong and serviceable. In tight spaces on a boat, using a crimp tool can still be done – many crimp tools have long handles or hydraulic heads that can fit where a soldering iron might be awkward. The main “challenge” with crimping is ensuring you have the correct size connector and tool for the job, but manufacturers like Ancor make 6 AWG butt connectors readily available, and using the matching die on a crimper will yield a consistent result.
Soldering a heavy-gauge marine cable, by comparison, can be more demanding in practice. First, producing a good solder joint on 6 AWG wire requires a very high heat source – typically a large soldering iron (200+ watts) or a small torch. Applying sufficient heat to the joint without melting too much insulation is a delicate balance. On a rocking boat or outdoors (wind can cool the joint, and open flames are risky), this becomes even more challenging. It’s easy for an inexperienced person to underheat (resulting in a cold solder joint that looks dull and weak) or overheat (damaging insulation and charring the wire). As one marine how-to author notes, soldering on a boat “takes practice” and “requires a quality soldering iron”, especially to do it reliably in less-than-ideal conditions . In the context of splicing an in-place wire run, one might have to solder overhead or in a confined compartment, which is far from the ideal bench setup. Additionally, soldering thick wire is time-consuming – you must heat the copper mass evenly and feed solder until it wicks fully through the splice. Any movement of the joint before it cools can ruin the connection. Once soldered, you need to clean any flux residue (to avoid future corrosion) and then apply heat shrink or tape. Overall, soldering is a more skill-sensitive and time-consuming process than crimping for this size of cable.
In terms of convenience, crimping also has the edge: no electricity required (useful if the boat’s electrical system is a work in progress or if you’re docked without power), and no open flame. Soldering in a bilge or near fuel lines is obviously a hazard, whereas crimping is cold-work. The only scenario where soldering might seem “easier” is if one does not have the correct crimp tool at all – but given the importance of this connection, investing in the right tool or hiring a marine electrician to do the crimp is well worth it. In fact, some boaters who lack big crimpers will take their cables to a battery shop or marine service center for professional crimping rather than attempt an inadequate DIY crimp or a risky solder job. To summarize, for a one-off splice, crimping with the proper tool is generally easier and more foolproof. Soldering heavy cables is doable but requires much more know-how and care to get right, making it less practical for most boat owners in the field.