Trolling wire voltage testing.

Discussion related to commercial salmon trolling, boats, gear, fishing techniques, electronics, marketing, etc.
Once and Future
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Re: Trolling wire voltage testing.

Post by Once and Future »

Garris: the trouble with this subject is that there are so many details and theories that it rapidly gets too complicated for anyone to understand. I am not the ultimate expert. But what I try to contribute is to subtract concepts from the discussion that are more trouble than they are worth. Not being perfect, I welcome corrections if I state something wrong. Having said all that, here are a few responses to your post:

1) I do not think of the bonding system as being an anode and/or a cathode. To me, the bonding system is tying most of the metal pieces on the boat together with conductive material. This is important to insure dissimilar metals in contact with one another do not create a stray voltage due to the battery effect. The only anodes in the system are the zincs that are tied to exterior metal underwater. (I do not understand the concept of why some think it is also useful to have aluminum anodes.) So, a properly bonded system, with zincs attached, has a goal of showing zero voltage difference between the boat's metal and the ocean. The zincs diminish as they give up their electrons to bleed off whatever electrical charge inadvertently appears; and thus maintain a zero voltage difference. So at this point, we consider hull potential to be equal to ocean potential, and we find it convenient to measure that at the (bonded) rudder post. The hull should be neither positive nor negative with respect to the ocean. There is zero difference.

2) I agree with the concept that there should be no loops in the bonding system. The bonding system should be like the twigs and branches of a tree leading to the trunk.

3) OK, so let's say we have the boat properly bonded and and zincs are in place. But we have to put our stainless gurdy wires into the water to catch fish. Some observant fisherman who was smarter than me learned that he caught more fish if there was a slight positive charge on the gurdy wire. The only way to achieve that would be to isolate the gurdies from the bonding system. So most of us do that by insulating the mounting feet of the gurdies. Now, if you do that, then lower a cannon ball over the side off your gurdy, I predict you will be able to measure a voltage difference between the submerged wire and the rudder post. I have been told +.6 volts on the wire compared to the rudder post is good. I think Lulu recommends something a little higher. If guys find their own number is off a little bit, this is where they install the Russell Black Box and dial it in a little bit more.

4) Icharge is proposing a new voltage measurement that he feels is more telling. If I understand correctly, he suggests measuring between the gurdy wire and a bundle of stainless wire in the water a few feet away. I haven't tried that measurement because I am a long ways from my boat right now. Plus, I haven't been able to follow him completely on his theory.
Scotthmt
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Re: Trolling wire voltage testing.

Post by Scotthmt »

I wouldn't worry about voltage too much in your first season, other factors will have a much bigger impact on how many fish you catch. I.e. Hook sizing, hoochie color, spread length, spoon type, troll speed for certain things, etc etc. just bond your boat, isolate the gurdies, take a voltage test and if it's within range just fish it.
gchuba
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Re: Trolling wire voltage testing.

Post by gchuba »

I may very well be keeping my boat as a rod and reel craft the first year with the possibility of a single gurdy on starboard and port sides. As I do the installs I want to keep this electrical theoretical stuff present so I am not repeating myself. I am not swimming in funds or time and enjoy doing this sort of thing piecemeal. I had to really study what was being said. In simpler terms for my thinking: cathode = "+" of battery (and the "t" in the word cathode reminds me of the + sign), anode = "-" of battery("t" is missing). Bonding = all the metals of the boat plus the negative of the battery going to a sacrificial metal (zinc). My amazement comes from the fact that the negative of the battery as well as the connected bonded metals that go to the zinc in the water also act as a positive charge which is why the zinc disintegrates. The zinc (and for sake of definition) would be considered a metal alloy (along with magnesium, aluminum, and possibly others) with a more active voltage than the metal they are protecting and a more negative reduction potential (swallow-er/eater of electrons) and is of a material that dissolves easily (I believe the electrical dissolving term would be "positive electrochemical potential" that through osmosis dissolves). Those terms and concepts are foreign to me so....the zinc is a metal that breaks down easy to protect the electrical. Basically, to my understanding, a boat is a floating battery whose construction and wiring create a battery field that is negated by the zincs and the proper grounding of everything prevents sparks. Truly a concept I never delved into before. I always thought the battery(s) for starting the motor and running things was the only charge to worry about. Once and Future summed it up well with practical application. I brought up "electrolysis" with my plumbing with analogy with brass as the connector between copper and galvanized pipe to prevent corrosion. That in turn makes it a poor replacement for the zinc but a good connector for the connections when grounding/bonding dissimilar metals and wire leading to the zinc (nothing I read....just something I applied when attempting to understand the principles brought up in this discussion). My best to all.
Garris
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