Transducer Cable installation

[jaymoussy]

I am just about to run a transducer cable through the rigging tunnel on my Montauk 170, using the factory pull string, and found great tips on the old forum (thanks Jim!) I will pull a new string along with this new cable, probably the weed-wacker-type, with some lubricant for good measure.

While I am working in this area and running a new cable and string through the tunnel, are there any other possible item I should consider running? This is an inshore boat, so I do not plan on having anything fancy going.

Well, this work is not for today, weather system the size of California passing over the eastern seaboard right now. I see a few local fishing boats out on marinetraffic. Hard way to make a living.

[jimh]

When pulling a new cable through a below-deck conduit like the rigging tunnel on your Boston Whaler center console boat, I recommend trying to avoid, as much as possible, creating a weaving of the new cable through any existing cables. If the existing pull string has become wrapped around the existing cables, any new cable you pull into the conduit with that pull string will become wrapped and woven among the existing cables. It is preferred to install the new cable so it just lays cleanly in the conduit without wrapping around existing cables. If the existing pull string does not provide that, give consideration to installing a new pull string which will not become entwined with existing cables. You can usually use an electrician's fish tape to install the new pull string.

For wire lubrication--if even necessary--you should use a proper water-soluble wire-pulling lubricant that will dry to a powder and can be flushed out. You do not want any grease in the conduit.

The cable connecting a SONAR transducer to its head-unit should be kept isolated from other electrical conductors in order to avoid ingress of electrical noise into the SONAR device. This is another good reason to avoid entwining this cable with other conductors.

I don't have any suggestions for what other conductors you might want to pre-install into the conduit.

[jaymoussy]

I see the problem, where the factory string may be intertwined with other components.
The boat is as it left the factory, no add-ons in the rigging tunnel, though.
How big is the rigging tunnel anyway?

I do like the idea of pulling a hose first (size TBD), and spare string, using stock string, then pulling my new cable trough the hose. This could provide a bigger interference "air gap", and some protection from tunnel grime.

Is the electrician's cable lubricant the right type, or does it leave a problematic residue?

[Jefecinco]

If your intention is to use a string trimmer poly/plastic string in place as your new or replacement pull string I recommend you leave the factory nylon pull string in place as a back up pull string. I've found that some poly/plastic string can significantly weaken as it ages. Monofilament fishing line is a prime example but is by no means the only one.

The recommendation may be over cautious but if a string pull fails it can cause a lot of frustration.

[jimh]

A simple way to install a pull string in a larger diameter conduit in which there are existing cables laying in the conduit is to attach a very light string to a small ballon. Inflate the ballon so its diameter is a bit smaller than the space remaining in the conduit. Then use a shop-vacuum and hose to blow and push the ballon thought the conduit. This will assure that the new pull string is running atop all the existing cables and not woven among them.

I also don't like mono-filament line as a pull string. It is hard on your hands and tends to not lay nicely in a coil when not in use. A woven light string is better.

[porthole]

On my 17' and 21' Outrages, both had factory strings in the wiring chases. Neither were usable as over the years they had been wrapped up in the other wires.

My 15' Whaler was the easiest. The wiring tunnel was so big and smooth that wires could be pushed through with no tools.

[jimh]

Another tip on the pull string: make the string more than twice as long as the conduit. With a longer pull string, there is no need to replace the existing pull string with a new one on each pull. I have such a pull string in the rigging tunnel of my boat. To add a cable, I just tape it to the pull string, pull it in place, and the pull the excess pull string cable back to one end of the conduit.