Troller wiring (I hate electrical problems!)

[TIM WEBB]

I've been having a slow battery drain lately, and I suspected this connection after putting a meter across the un-connected battery ends and seeing resistance. The fat wires come from the battery in the cuddy, the skinny ones go to the troller. This connection lives under the port gunwale, resting on top of the flotation foam (DS2).

Despite being encased in about 10 coats of Plastidip and zip-tied together, corrosion found it's way in (the kind you get on your car battery terminals - I've already removed the Plastidip and cleaned off the white corrosion in this pic), and the positive connection (zinc plated copper terminals, SS nut, bolt, and washers) rusted. Result: a short. Not enough to trip the breaker on the battery box, but enough to draw down the battery in 3-4 days.

Even without factoring in the water I've had in the bilge, I consider it a "wet" location due to condensation. Any ideas on a better solution? Do they make some sort of crimp that would allow a direct connection? How to best insulate? The fat wires are multi-strand 0-1 gauge silver, and the troller wires are copper.

Any and all suggestions would be appreciated, thanks!

[TIM WEBB]

Is there maybe a way to solder the skinny wires directly to the fat ones? Been pondering a solution all day ...

[Thomasjbrothersjr]

I work in the electrical field. We have used a few different 3M products when splicing has to be done underground or in manholes where they are actually submerged in water 24/7. One type is a resin filled splice tube. After you make up your splice it is enclosed in plastic case and filled with resin. After it hardens there is no way water can impinge on the connections. It is permanent however. We have also used a re-enterable type splice like the one I just described. Instead of resin it is filled with a gelatinous silicony type product. The case can be reopened and worked on, refilling it when done. We use this type in manholes where it maybe important to add another line to the system. These come in all different sizes.

Have you visited your local electrical supply house? I don't mean Home Depot or Lowes but a legitimate electrical supplier. Ask them what they have. I would stay away from anything that simply shrinks wraps onto the wire.

[GreenLake]

Is there maybe a way to solder the skinny wires directly to the fat ones? Been pondering a solution all day ...

You never want to solder on a boat. The wire stiffens, and vibration will break the strands over time. Now this depends on how hard you use your boat, but why go there?

T..jr had some interesting tips. In places that allow regular inspections, like trailer lights, I've used simple dielectric grease to delay the damage to where I can stay on top of it.

[TIM WEBB]

Thanks a bunch guys. Think I'll pay a visit to City Electric tomorrow ...

T-Bone: what sort of splice would you do between these wires?

Yeah, soldering would have been my last resort. Only considered it after a google search on "attaching skinny wires to fat wires" or something to that effect. Nothing marine-specific. Most of what turned up was info about installing high-end sound systems in cars (you know, the annoying thump thump thump you hear coming from the low-rider next to you at the stoplight?). In fact, those fat wires I'm using are intended for that purpose. I installed them in an effort to reduce voltage drop between the battery in the cuddy and the motor on the transom.

All other connections in my electrical system are crimped with waterproof heat-shrink fittings, but the only other ones in a "wet location" (also under the gunwhale) are the radio connections, and I've seen no signs of corrosion there.

[Thomasjbrothersjr]

The connection type I would use is a butt splice. Not your crimp type but a mechanical connection with a screw down point of contact. The real issue isn't the type of connection but the case and its type of fill. I just googles 3M splice kit and had huge results. Resin filled will be the way to go if you are looking for permanency. They are not cheap but should offer the best solution to joining wires together that may then live in an exposed and wet environment. One thing to make sure you know is the wire size when you go to the supply house. It will dictate the size product, butt splice, tube etc.

Good luck Bro,

T-Bone

[TIM WEBB]

Thanks TB!

Guess I'll find out 2morrow. I'll make sure I have the right wire sizes before I go.

The only other caveat is that whatever I end up doing needs to fit through a 2" hole, as I'm gonna have to feed the connection back through the opening in the cuddy bulkhead ... ?

[jdoorly]

Tim, your problem is galvanic corrosion, also known as electrolysis. It occurs when 2 dissimilar metals are in close proximity to salt water. The metal with too many electrons loses electrons (corrodes) to the metal that has too few electrons (corrodes NOT), and electrical current flows between them. Stainless and zinc are very bad, stainless and copper are OK, stainless and galvanized are very bad, zinc and aluminum are OK. Your connections probably corroded due to the combination of copper and zinc.

I went through the same thing you are (I even used the same 0/1 speaker wire), but it's been a couple years and I have come up with a better solution. Run the 0/1 under the coaming/seat out to near the trolling motor (in seatback or kick plate). Terminate the wire with an 0/1 ring (1/4" hole)(available from same vendor as wire). Drill two 1/4" holes (2" apart) in the fiberglass near the motor (you may need to cut an access port also). Put two 1/4-20 x 1" stainless bolts through the ring terminations and through the holes and fasten with a nyloc nuts. When you are to use the trolling motor just attach the motor wires to the bolts with alligator clips.

The copper wire, the tin terminal, and the stainless bolt are all within acceptable range of each other, although you could try to go copper wire-copper ring-bronze bolt-bronze nut for minimal galvanic corrosion. Using a non-hidden connection (alligator clips) lets you moniter for corrosion and de-couples the circuit.

[Thomasjbrothersjr]

Not having read your post careful enough I missed the two dissimilar metals part. We use a product made by Ideal called Noalox. The terminals, wires and any part of the splice are coated with this stuff. We affectionately call it monkey $#!t. It is tough on clothes. It does the trick combating electro galvanic corrosion though. Pretty cheap for a small bottle.

[jdoorly]

T..jr, I tried using that stuff (from Radio Shack?) a couple years ago on my trailer lights, but didn't have the success you appear to have had. Maybe I didn't apply it liberally enough, or maybe there was just no fixing the trailer lights from Hell! Have since gone with a dry trailer light system. It is probably a good idea to use the stuff, but it's a better idea to first mitigate the problem's cause.

When I was in the Navy the ship's bulkheads (walls) always had these 1" tubes welded perpendicularly to run cables from one room to the next. The empty part of the tube would be filled with a putty to keep it watertight. This brown putty was affectionately known as monkey sh*t, as well as, of course, half the dishes served in the galley.

[TIM WEBB]

Well, I went to City Electric to pick their brains a bit. First thing he suggested was to take everything apart, clean off all the corrosion, then grind the zinc off the terminals and get them down to bare copper (agrees with what you were saying Jay). Next thing he suggested was coating everything with Noalox (sold me a small bottle for $15 T-Bone) before reassembly. Other than that, he didn't really seem to think there was anything wrong with my mechanical connection. Lastly, after reassembly, he suggested I coat everything with a 3M product that you brush on and it hardens as it dries. Small can = $20.

Last evening I did all of the above, but not sure how well it came out. The 3M stuff is still soft today. I *really* laid on the Noalox thick, and I forgot to ask if it was supposed to dry before applying the 3M. Does it dry TB? Guess I'll see if it's dried yet after work. He said put on at least 3 coats of the 3M. They didn't have anything like the resin filled tube you describe.

I like your seatback connection solution Jay, but unfortunately my 1/0 wires don't reach back that far. I bought 25 ft of it, and 12.5 x 2 ft doesn't reach from the battery box in front of the mast, up along the cuddy roof, through the bulkhead, and back to the rear of the seat ...

[Thomasjbrothersjr]

I too lay the stuff on thick, however I never have to coat the wires with anything like you Have. I don't think the stuff hardens up, it may dry out, after years. It is still soft and smearable when I have had to change connections later on in its life.

I love the idea of the alligator clips, plug and play like.


T-Bone

[TIM WEBB]

I took a look at the connections again tonight, and the 3M stuff *is* starting to "cure". I think it may have formed enough of a "shell" around the Noalox that I might be able to now add additional coats to "firm it up". When I'm satisfied that the connections are sufficiently insulated, I'll wrap some kind of additional insulation (closed-cell foam or the like) around both sides before feeding them back through the bulkhead. Then I'll cross my fingers ...

Monkey sh*t: that's funny! That's the term my wife and I used to describe what came out of our daughter's rear end the first few months ...

[jdoorly]

Hey Tim, late thought. Your picture shows the 2 splice points parallel to each other. It's a good idea when you working with high amps to stagger the 2 joints so they will never come in close contact. However, it sounds like your layers of stuff probably has a higher insulating rating than the wire cover.

[TIM WEBB]

I think you're absolutley right, and that the one major flaw in my original istallation was zip-tying them together, before plasti-dipping, relying only on the thickness of the fat wire insulation to keep the connections separated, and assuming (hoping?) enough plastidip would flow into the space between them. I really have no idea why I thought they needed to be secured together in the first place?

At any rate, I ended up encasing each connection separately in several more coats of the 3M stuff, as well as more plastidip to boot. On top of that I slipped a short length of silicone tubing (like surgical tubing) over each connection and zip-tied those in place. I would not have been able to secure the two sides together after that even if I wanted to, because the whole thing would have never fit back through the hole. Sorry, but I didn't get a pic of it - it was getting dark, and I was trying to get it all back together in order to be able to hit the lake the next day ...

Ohmmeter now shows nothing at all when placed across the unconnected battery-end leads, so hopefully I can now finally cross this project off the list once and for all!

Thanks again to all who offered their advice and assistance.