Black Box

[Once and Future]

I'm a dope. Up above I have an inaccuracy. 700 milivolts actually equals 0.7 volts.

Nothing like a little disinformation to help with the brain snakes. And that always seems to happen on the topic of black boxes.

[Salty]

Great thread.
Early in the 80's I bought my first black box to hook up on my wooden troller. I had a fabulous trip. My partner, who knew I had purchased the box, commented that I must really be happy with it. I said, "I am, it is working so well just sitting on the counter that I can't wait to hook it up and really start catching."

[mb4570]

How do you check line voltage on aluminum boats? 34' aluminum Power Troller Canadian built

[carojae]

mb, I imagine you just do like any boat. You put the negative on your hull and the positive on your wire while the line is submerged. Not for sure but that's what I'd do.
The gurdys are isolated therefore the wires?

[mb4570]

Ok thanks I'll give it a try, wasn't sure it was the same as wood boat or glass boat but makes sense to use same test. Thanks

[Robot]

I remember this topic from a while back. When I first joined this forum. Figuring out the fish was more than enough of a task for me at that time (with only a 1 king salmon score before I bought a permit and boat with cash!) I've since upgraded permit and just recently, boat. I thought you guys might enjoy some real BrainSnakes with a picture of the blackbox headunit system rigged on this sweetheart.

Note: She has 6 total 3" diameter anodes(?) below the water line on the hull too.

[Lulu]

Crawfish's post from Feb 1: When everything is right, my one man operation can keep up with the highliners with crew. However, Lulu is a steel boat and the smallest of things can, like corrosive wire/terminal, create brain snakes until you find the problem. One thing I am absolutely convinced is the BB pays for itself when the fish are on top. Also, nearly every trip the biggest fish come on the top snooter spoon. That's an indication that the boat's electrical water signature is attacking fish to the boat. Someone posted a observation about one side fishing better than another, that's a red hot flag that something is wrong and you're losing production.

Someone else posted a thought about consistency. I absolutely agree. The BB helps keep the wire voltage constant for all six wires. Don't give the finny bastards a reason to not bite. Everything has got to be equal in a scratch bite or they just don't bite except for the stupid ones.

I've written it before and I'll repeat it. Don't get into a BB unless you want to stay up with the checking and maintenance. It's better to understand your boat's profile in the water, keep the anti-fouling paint fresh, new zincs (and scrub them a couple of times during the season), and make sure all electrical connections are clean; especially the bonding system.

And for the posting about pink snaps, turn the box down!!!

[lcharge]

Well said Lulu. I've been out of commercial fishing for years, so I don't know what guys are using for bottom paint nowadays. We always used International copper paint which was somewhat absorbent, for lack of a better term. I believe that when you painted a steel rudder, for example, the steel under the paint was allowed to still interact with the zincs and to contribute to the overall hull's voltage field. If one went to an epoxy type paint where the coating was waterproof (insulating), your zincs would not corrode adequately throughout the season. That is something a guy should watch. If you changed paint recently, and/or your zincs do not corrode enough, take a close look at the paint you are using. Some guys with wood or glass boats used to leave their rudders unpainted so as to have a better reaction with the zincs, as the rudder is one of the largest underwater metals. I did this one year myself, but did not see any significant difference in the zinc corrosion over the season (International xxx paint). The strongest voltage contributor will most likely be the stainless or monel shaft and any (high) bronze fittings. They are higher on the galvanic scale than steel or copper and therefore will have the greatest reaction with the zincs. Every underwater (and above water) metals should be interconnected with the bonding system. In agreement with Lulu, I can't stress enough to go over all your underwater connections every year and to check the electrical continuity between each and every component and your bonding system. Don't forget the shaft bearing and rudder stock bearing housings as well as all metal through hull fittings. The extra hour it will take to do this will put fish in the boat. Also be careful not to overzinc. I used to judge my zincs so as to have about 1/8 to 1/4 of the original zinc left at annual spring haulout, and my boat was "fishy".
If you are using a multimeter to do an ohm (resistance or continuity) test on your under water metals to bonding system, remember that you can show continuity and still have a poor connection. The best test is with a power source and a light bulb (a modified flashlight will work). Just try to route the light bulb's ground through the component that you are checking and through the bonding system. If the bulb is weak or doesn't come on, clean the bonding connection until you get a strong light.
If you have a metal boat, try to place your zincs evenly throughout the hull. A zinc will perform only out to a certain radius. So often I see sportie boats with aluminum boats and all the zincs clustered across the transom. Look at a ship or steel barge out of water. The zincs are pretty evenly spaced for just that reason. I've hear that this does not apply as much to boats made of anodized aluminum. I have a hard time swallowing that, unless the aluminum has an insulating coating on it.
Good fishin
www.lurecharge.com

[Lulu]

Bottom paint!!! I have a story.

The boat wasn't fishing worth a nickel. I was getting out fished by boats that shouldn't have been on the water and guys that didn't know the difference between a hoochie and a spoon. I checked and tried everything; spent hundreds of dollars on the phone with Malcom. Literally was on the back deck ready to cry. I went so far as to buy a new set of leads that I watch get poured from the purest lead available. Desperate people do desperate things.

A chance conversation with a buddy came to a conclusion that it must be the bottom paint. So I did my research. Turns our there are two types of bottom paints, both have similar concentration of cuprous oxide. The copper in the paint kills the critters and reacts with the zincs, i.e. more hull potential, bigger electrical footprint in the water, fish can find you better. One type is a sluffing paint (like Trinidad Pro) and the other is a hard bonding paint (like Ameron's ABC). The hard fouling paint is great for hull speed, but the polymers insulate the copper until it is activated by contact with water (functionally isolating the hull potential of the boat) and the copper is not evenly distributed throughout the hull. Guess which one I was using.

When I just bought the boat I let the shipyard talk me into the ABC, not knowing squat about a steel boat at the time. Over time and many multiples of new ABC coatings, I functional inhibited the nature hull potential. All the wire and hull potential readings were dead on, there weren't enough ions trailing the paint. I basically had the same electrical profile as 16 foot sport boat.

I pulled the boat out of the water, hard sanded down to barrier coat, and slapped on three coats of Trinidad Pro with 60% cuprous oxide. First tack was for 44!!! Up to that point, I probably hadn't caught 44 for the first month of the season. It ended up being a 100+ day.

Turns out the old sluffing bottom paint always has copper active throughout the hull, but not evenly. What I learned from a chemist at Trinidad paints (the technical service rep couldn't answer my questions so he plugged me into a research chemist) was the copper falls out of solution very quickly. You have to stir vigorously every time you pour into the paint tray, and not with a paint stick. Use a drill with a paint stir. And, for a troller's or tuna fisherman's application, ALWAYS, use the bottom of the paint can on the back of the boat. The bottom of the can will always have the highest concentration of copper.

This is not an advertisement for Trinidad. Any sluffing paint will do. Anything over 30% cuprous oxide is over kill. But what the hell, more is better right?

Lesson Learned: Don't use the new high tech paints. They do what they're designed to do. But, ain't worth a nickel for a salmon boat.

[Lulu]

One more comment. You are dead right about not painting the rudder. Other than the engine (which is your ground), the rudder is the biggest piece of metal and the single biggest active surface in the water. Use it to catch more fish.

[lcharge]

Great story and makes the point. My only argument might be that unless there is enough copper in the paint to allow voltage to pass through it (conductive), the zincs will not interact much with the paint. What happens is that any metal that has an oxide derivitive (iron oxide, aluminum oxide, copper oxide) will possess both anode as well as cathode. When these metals are placed in the right environment, corrosion occurs resulting in a voltage being created. A plain piece most any metal will corrode (pitting) and generate a voltage field when placed in a wet and oxygen rich environment. One exception being gold which does not have an oxide derivitive.
I believe that a higher concentration of copper paint near the stern will naturally give off more of a voltage field than areas with lesser copper content. If I am right, the paint itself will give off a small voltage field as the copper oxidizes. The results may be the same as yours, just the process is different.
The zincs being close to a more noble metal doesn't create a voltage producing cell. I proved this by placing highly reactive magnesium close to noble metals and in sea water, for up to 2 weeks and with no reaction. The magnesium only reacted when contact was made with the noble metal.
To get across just how sensitive fish can be, here is one of my favorite research articles. Hard to believe somebody figured this out 100 years ago. They don't say what type of metal was used, but it still makes the point. I assume that it was a single element like iron.

Brian L. Keeley. Philosophy/Neuroscience/Psychology Program, Washington University
By the turn of the century, some began to suspect that, in addition to the ability to generate elec­tricity, some animals could detect the presence of electricity in their environ­ment. The electrosensory hypothesis gained credibility in 1917 when Parker and van Heusen discovered that non-bioelectrogenic catfish could detect galvanic and direct currents. They did so through a series of experiments in which they presented blindfolded catfish with glass, wood & metal rods. The fish were able to detect the presence of metallic rods, but only reacted to the glass and wooden rods when they touched the surface of the fish. They went on to show that the type of behavior (to flee from or to approach and "nibble" at the metallic rod), elicited by the presentation of rods could be modulated by changing the length of rod exposed to the water. Parker and van Heusen correlated the amount of exposed metal with the amount of galvanic current produced by the rods, and then reproduced the behavioral results using direct electrical currents presented via electrodes placed in the aquaria with the catfish.
They go on to say: Notably, they do not posit an electroreceptive modality. Rather they propose that electric detection is mediated by the gustatory system, more specifically, by the taste buds. Their reasoning was that, electrical stimulation elicits feeding responses and these behaviours are typically mediated by the gustatory system. The head of the catfish is the most sensitive to stimulation, and most taste buds are found in the head, and “This assumption is completely in line with what has been known of human taste organs. For these are easily stimulated by direct currents of very low energy value”.

[Lulu]

You missed the point. The copper does not interact, to any large degree, with the zincs. The copper ions are sluffed off as the paint works plus the forward motion of the boat knocks them off. The boat's ion cloud is what the fish sense with their lateral line. Copper (which is relatively highly charged; +2 electrons) from the paint is one source of ions (also called charged particles in the world of physics). The zincs sacrificing to dis-similar metal is the primary source. Again, rudder is big surface for zincs to work against creating more ions.

Obviously, the bigger the ion cloud the higher potential salmon and tuna will find your boat. It doesn't make them bite. It just gets them closed enough you can do something about it. That's why they call it fishin and not catchin.

[lcharge]

You call it "sluffing", I call it "reduction and oxidation" (REDOX). Same language, different dialect. As far as the voltage not making them bite, this guy (below) thinks otherwise. As indicated by the last paragraph, us humans are effected as well, ..... though I don't recall getting hungry during an electrical storm.
Scientists seem to have nailed down the electroreceptive organs in sharks and rays as being Ampullae of Lorenzi, but have yet to have a consensus on salmon and others, but believe that the receptors are also within the fishes heads and may be an extension of lateral line hairs.

Brian L. Keeley. Philosophy/Neuroscience/Psychology Program, Washington University
By the turn of the century, some began to suspect that, in addition to the ability to generate elec­tricity, some animals could detect the presence of electricity in their environ­ment. The electrosensory hypothesis gained credibility in 1917 when Parker and van Heusen discovered that non-bioelectrogenic catfish could detect galvanic and direct currents. They did so through a series of experiments in which they presented blindfolded catfish with glass, wood & metal rods. The fish were able to detect the presence of metallic rods, but only reacted to the glass and wooden rods when they touched the surface of the fish. They went on to show that the type of behavior (to flee from or to approach and "nibble" at the metallic rod, elicited by the presentation of rods could be modulated by changing the length of rod exposed to the water. Parker and van Heusen correlated the amount of exposed metal with the amount of galvanic current produced by the rods, and then reproduced the behavioral results using direct electrical currents presented via electrodes placed in the aquaria with the catfish.

They go on to say: Notably, they do not posit an electroreceptive modality. Rather they propose that electric detection is mediated by the gustatory system, more specifically, by the taste buds. Their reasoning was that, electrical stimulation elicits feeding responses and these behaviours are typically mediated by the gustatory system. The head of the catfish is the most sensitive to stimulation, and most taste buds are found in the head, and “This assumption is completely in line with what has been known of human taste organs. For these are easily stimulated by direct currents of very low energy value”.
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