Copper, Monel and Lead Core Fishing Lines - Heavy Deep Trolling Lines
Copper fishing lines have been in use for a long time, but only recently they have been put to general use by introduction of multi-strand copper fishing wires.
Monel fishing lines are heavier than steel wires, but more durable than copper wires. They are also more expensive than copper lines.
For monofilament, fluorocarbon, braided, steel fishing line and fishing lines in general, feel free to check Types of Fishing Lines article (link opens in the new window).
Characteristics of Copper, Nickel and Monel
Pure copper (Cuprum - Cu) is reddish, soft, ductile and malleable metal with very high thermal and electrical conductivity. For fishing, it is important to know that copper density is around 8.96g/cm3 at room temperature. Pure copper, coated or not, is used for single or multi-strand fishing lines, almost exclusively for trolling rigs.
Pure nickel is silverish metal with density of around 8.9g/cm3 - very similar to copper. It is harder and stronger metal than copper, but harder to work with and more expensive. Pure nickel is not used for fishing lines.
Monel is an alloy composed primarily of nickel (up to 67%) and copper. Other alloying elements are iron, manganese, carbon, silicon, aluminum, titanium etc. - depending on the monel alloy type. Monel alloy is a very expensive material, not easy one to manufacture, with cost ranging from 5 to 10 times the cost of copper and nickel combined. But, it is also stronger than pure nickel and very corrosion resistant, even to rapidly flowing seawater!
Density comparison with other materials is given in the following table:
|Material||Density (g/cm3, kg/dm3, kg per liter)|
|Fresh Water||1 (@ 4°C, 39.2°F)|
|Sea Water||1.025 (on average)|
|Monel||8.85 (alloy dependent)|
Note: for many applications, it is very important to know total weight of the line, so some manufacturers provide information as 'Feet per Lb.' or 'Meters per kg' - that parameter is simply a length of a pound of fishing line in feet or a length of a kilogram of fishing line in meters.
Copper Fishing Lines
Copper fishing lines are very corrosion resistant. To increase the resistance even further, some companies use nickel and/or tin coating.
Single strand copper wires are not as flexible as multi strand copper lines, but they are less abrasive and more abrasion resistant than multi strand copper lines.
Most of the manufacturers of copper fishing lines sell copper lines in numerous lengths, because it is highly recommended to spool these lines on the reels without knots of any kind. Of course, baitcasting reels are highly recommended for most applications using copper lines.
Copper lines don't stretch very well - they stretch up to a point, especially before breaking point, but after such load they don't return to the previous state. Be sure not to set initial drag on the reel too high - after fish is hooked and rod starts to neutralize fish strikes, feel free to increase the drag up to one half of line test strength (breaking strength in pounds or kilograms).
It is said that copper and, up to a certain degree, monel, attract the fish during trolling because they are good electric conductors. Marketing trick or not, copper wires do have better catch rate in many situations, when compared with braided, fluoro and nylon lines.
Copper fishing lines are not as strong as other lines, regarding line thickness - for example, American Fishing Wire Surfstrand Copper 1x7 Bare Trolling Wire thickness to test pounds:
- 30 pound line - 0.028 inch (0.71mm) diameter,
- 45 pound line - 0.037 inch (0.93mm) diameter.
Also, these lines are not as abrasion resistant as steel wires nor their surface is hard as steel wires - don't go shark fishing with copper fishing lines - they are harder than nylon mono lines, but ... Also, kink resistance of copper wires could be better :)
Due to copper's density of 8.96g/cm3, copper fishing lines sink much more than ordinary lines - for example, Blood Run Tackle Copper Fishing Line dive depths are around:
- 20 pound copper fishing line - 8 feet of depth for every 50 feet of line released at 2.5 mph (2.43m of depth for every 15.3m of line released at 4km/h or 2.2 knots),
- 32 pound copper fishing line - 8 feet of depth for every 50 feet of line released at 2.5 mph,
- 45 pound copper fishing line - 9 (2.75m) feet of depth for every 50 feet of line released at 2.5 mph,
- 60 pound copper fishing line - 11 (3.35m) feet of depth for every 50 feet of line released at 2.5 mph.
Of course, actual lure or bait depth depends on many factors like:
- speed and direction of underwater currents,
- lure and bait buoyancy and drag resistance,
- trolling speed,
Recommended usage: use copper fishing line as the main line and good fluoro line as the line leader - few feet (not more than 20 feet) is more than enough. Leader line length, of course, depends on fishing depth, trolling speed, how clear is the water, daylight conditions etc.
Monel Fishing Lines
- monel lines are thinner than copper lines for the same strength, for example American Fishing Wire Monel Trolling Wire thickness to test pounds comparison - 30 pound monel line has 0.022 inch (0.56mm) diameter vs 0.028 inch (0.71mm) diameter of copper fishing line.
- they are more abrasion and kink resistant than copper lines, but less than steel lines,
- monel trolling lines sink better than steel fishing lines.
- these lines have much harder surface than copper lines and can withstand, up to a certain degree, shark teeth - much better than single or multi strand copper wires, but not as good as steel wire.
As said before, monel lines are more expensive than copper wires, but obviously that difference is for a good reason. However, if you don't plan on fishing where sharks are present, why bother with monel lines when there are cheaper copper lines around. After all, this monel bite resistance is important ONLY when there are no leader line between monel main line and the lure - and since monel lines are very visible, a fluorocarbon leader line is highly recommendable.
Of course, bite resistance is not the only advantage of monel lines. If you are trolling above rocky bottom, or if there are structures of any kind on the sea floor that can snap the main line - monel line is the way to go.
Kink resistance - well, be careful with your lines and always keep them under tension and when fish strikes, be sure to respond right away.
For deep sea trolling, monel vs copper fishing lines - IMHO, go for copper, but stay open minded! :)
Lead Core Fishing Lines
Lead core fishing lines have core made out of lead and protective coat made out of nylon/Dacron/Trilene/Spectra. This protective coat also gives load strength to the fishing line.
Due to the lead density of 11.34 g/cm3, lead core fishing lines have potentially the greatest dive capacity of all the 'heavy' trolling fishing lines.
However, due to the usage of various coats, average density is decreased, when compared with pure lead wire. Generally, lead core fishing lines do have higher density than other 'heavy' trolling lines.
Lead core fishing lines are often colored in various colors, mostly in 10 yards or meters sequences for easier line monitoring during line release.
On average, 27 pounds test lead core sinks on average around 5 feet per color. A full 100 yards lead core line (10 colors) would be around 50 feet deep - keep in mind that lead core is very (trolling) speed sensitive fishing line, not to mention currents, waves and other factors that can influence its running depth.
Also, if you have two lead core lines in the water, roods and reels positioned on boat sides, during turns, due to speed difference of inner and outer lines, your lures are going to cover different depths, increasing the chance of fish strikes.
Stronger lead core line can, in theory, achieve greater depths. But, due to increased drag of thicker lines, faster trolling speeds can make them counter-productive. Thus, most fishermen using lead core lines use lines between 27 and 36 pounds test.
As with other similar lines, use of baitcasting reels is highly recommended. Keep in mind that lead core lines are generally weaker than other lines and require larger spools - also, they sink better and one needs less lead core line on the spool. :)
Heavy trolling lines - which one to use?
Personally, good copper fishing line is the best choice (best buy) for deep water trolling.
Monel's abrasion resistance to sharp rocks and objects is great feature, especially if you like to fish on such locations - there are reasons to avoid them, but more than often, predators feed on their prey on such positions.
Sure, using good sonar helps avoiding such objects, but when you are trolling few meters away from them on large depths, just a slight mistake and with a little help of underwater currents, your lure can end up in a ship wreck - forever :)