Running wires...

Waterwolf2230

Well-Known Member
Hey guys,

I picked up my new boat this weekend and am planning my attack on running wires from the roof of my boat into my cab. I have radar, compass and VHF to bring in. What is the standard practice for this? It’s my first time owning a hard top.

Secondly, if I have to drill into my roof, the smaller hole the better. Would you suggest cutting the wires to keep the hole smaller and then splicing/soldering them back together inside the cab and shrink wrapping them? The radar has actually 2 cables so the hole size will be pretty big if I don’t cut them.

I have 3M 5200, would that be a good sealant for the holes in the roof?

Thanks in advance, I have a LOT of work to do.

WW
 
I would goto a place like princess auto and pickup a wiring grommet kit (So you done chafe your wiring on sharp edges) and use good marine grade silicon like you have, after you have run the wires through the grommet to seal it all up.

Def use shrink tube and solder on connections, you can pickup non insulated connectors at lordco or even princess auto I believe as well.
 
Yeah drilling holes in your boat is always pretty tough, it usually takes me a week just to muster up the courage to do it. What radar do you have? 3G? i used a watertight cable gland that fit the little ethernet rj45 jack through it, was about a 7/8" hole which is pretty big but that gland is sealed and no water will go in there ever. When it comes to wire size, better to drill a slightly bigger hole and not have to cut the wire because a small hole leaks as much as a bigger one, but a cut NMEA or Enet cable has a much higher chance of failing when you need it the most. your compass is probably NMEA2k, i drilled a hole about 3/4" to pass it through, it sucks because that's a giant hole but that is the minimum size for NMEA. they really need to make those smaller! the way i did mine is i have an overhang on my roof in the front, so that hole doesn't need to be sealed because it overhangs to outside, and then redirected it into the cabin through a bluesea systems surface Cable clam, they are not cheap (~25$!) but they work really well and can keep your hole from getting stupid big. remember to keep the VHF antenna away from your compass, generally, 20" or more from the radar and 4 feet or more from the VHF. Also make sure that your compass location has no magnetic field interference around it, easiest way to know is to download a free EMF app on your smartphone. Place the phone with the app on where you are putting the compass. Generally it should show between 40-60 micro teslas in the area that you are hoping to mount the antenna. if it is showing a higher field you have too much iron in the area or a speaker or other magnetic field emitter around it. move the antenna. try it before you drill holes (don't ask me how i know!) Hopefully this helps!
 
For regular 12-volt wiring, you can cut and splice with butt end connectors (or just trim to length to avoid the splice) and a ratchet crimper. Use quality (i.e. marine grade) adhesive lined heat shrink connectors for the best connection - smear a some dielectric grease over the bare wire before crimping for best results. Soldering is not recommended on boats/aircraft where there is constant vibration as the solder makes for a brittle bond. All the stuff on your hardtop can be pretty critical and you wouldn't want it to fail at the wrong moment. I don't have much experience with cutting / splicing NMEA or ethernet cable. If needed, I would cut to length and replace the end fitting avoid splicing.

3M 5200 is more of an adhesive (and a strong one at that) than a sealant and usually used below the waterline or places where you don't want the surfaces to ever come apart. I would use 3M 4000 UV or Sikaflex 295 UV, 3M 4200 would work too but is overkill.

This might help clear up the different types of sealants: http://www.boatus.com/magazine/2013/April/assets/img/sealant-table.gif
 
As mentioned above - Definitely use wire/cable glands from a marine supply store - do NOT use 5200! it is a very strong adhesive and not really recommended as a sealant. If you are reasonably proficient as soldering then by all means for the VHF - as for the radar cable there are quite a few small wires which may need to be soldered (shield and cables) be prepared for a big job.
 
I've never done this, but if I were, I'd consider creating a single weather or water proof wire chase big enough to route the cables intact, with room for future toys as well.
 
Yeah drilling holes in your boat is always pretty tough, it usually takes me a week just to muster up the courage to do it. What radar do you have? 3G? i used a watertight cable gland that fit the little ethernet rj45 jack through it, was about a 7/8" hole which is pretty big but that gland is sealed and no water will go in there ever. When it comes to wire size, better to drill a slightly bigger hole and not have to cut the wire because a small hole leaks as much as a bigger one, but a cut NMEA or Enet cable has a much higher chance of failing when you need it the most. your compass is probably NMEA2k, i drilled a hole about 3/4" to pass it through, it sucks because that's a giant hole but that is the minimum size for NMEA. they really need to make those smaller! the way i did mine is i have an overhang on my roof in the front, so that hole doesn't need to be sealed because it overhangs to outside, and then redirected it into the cabin through a bluesea systems surface Cable clam, they are not cheap (~25$!) but they work really well and can keep your hole from getting stupid big. remember to keep the VHF antenna away from your compass, generally, 20" or more from the radar and 4 feet or more from the VHF. Also make sure that your compass location has no magnetic field interference around it, easiest way to know is to download a free EMF app on your smartphone. Place the phone with the app on where you are putting the compass. Generally it should show between 40-60 micro teslas in the area that you are hoping to mount the antenna. if it is showing a higher field you have too much iron in the area or a speaker or other magnetic field emitter around it. move the antenna. try it before you drill holes (don't ask me how i know!) Hopefully this helps!
It’s a Simrad 4G radar. What is the difference between the Blue Seas Surface Clam and a water tight cable gland? When I get home later I’ll post some pics. I’ll also pick up some 3M 4000 while I’m out. I bought the 5200 for my through hull transducer.

Thanks!
 
Years ago I had a tear in my Foruno radar cable. I called them to see if I could cut and splice the spot and they told me to never cut radar cable. VHF was OK but they said the shielding on the radar cable was critical to proper performance. I do not know if they just wanted me to buy a new cable from them but I did and did not cut.
 
It’s a Simrad 4G radar. What is the difference between the Blue Seas Surface Clam and a water tight cable gland? When I get home later I’ll post some pics. I’ll also pick up some 3M 4000 while I’m out. I bought the 5200 for my through hull transducer.

Thanks!
The Difference is about 24$. The cable glans are way cheaper, a couple bucks each but they may or may not fit the wire end into them. The 3/4" one should fit the RJ45 conenctor that comes at the end of your radar with some persuasion. i have a 3g, i am assuming yours is the same as mine, which means you have a RJ45 and then 3 wires, a black and red (power) and a yellow (trigger, wire this to a switch so your radar is not always on or it will kill your battery when not in use, ask me how i know:)) you could cut the RJ45 and redo but you have to be skilled in making twisted pair connections, it's the same as Ethernet connectors in your home and you need the special pliers. best not to cut if if you can avoid. if you do, make sure you avoid cutting back too much of the shielding, Enet is very fussy to having too much of the twisted pairs unraveled. as others mentioned, avoid using adhesives to plug holes, use proper cable clamps. that way if your component needs to be removed its not an adhesive nightmare to deal with. the VHF can be cut easily and then get a push type connector to get it back on. try to avoid putting wires too close to the vhf wires as you will get noise on your radio from it.
 
This is a photo of my roof. I was going to put the compass on the left and the VHF antenna on the right with the 4G radar in the middle. Both components are approximately 40” from the radar. I forgot to test for interference but will later tonight. I also ordered 3 ClamClamps from Blue Seas. Looks like an excellent system. I’ll seal them with 3M 4000 quick cure.
 

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This is a photo of my roof. I was going to put the compass on the left and the VHF antenna on the right with the 4G radar in the middle. Both components are approximately 40” from the radar. I forgot to test for interference but will later tonight. I also ordered 3 ClamClamps from Blue Seas. Looks like an excellent system. I’ll seal them with 3M 4000 quick cure.

Looks like a nice boat! The key is the distance between the compass and anything else, but that looks good to me. you do not need to seal the bluesea clams as they come with rubber gaskets. i like leaving things so they can be "taken apart" easily, but its up to you. do all of those standoffs for the antennas go directly into the cabin or they hang over the front of the windshield sort of like a baseball cap?
 
Looks like a nice boat! The key is the distance between the compass and anything else, but that looks good to me. you do not need to seal the bluesea clams as they come with rubber gaskets. i like leaving things so they can be "taken apart" easily, but its up to you. do all of those standoffs for the antennas go directly into the cabin or they hang over the front of the windshield sort of like a baseball cap?
They go into a cavity above the ceiling. My worry with just the CableClamp gasket is that there is a non-skid surface paint everywhere you can walk on the boat so it’s kind of like sandpaper. Not sure how well the gasket will seal on that...

As an aside I’m super impressed with the quality of the workmanship that RH did on my boat. I should do a separate post showing how they finished things. Exceeded my expectations which is always a good thing.
 
This is a photo of my roof. I was going to put the compass on the left and the VHF antenna on the right with the 4G radar in the middle. ....

When you say 'compass' are you meaning a fluxgate compass? If so, then you should not be putting it on the roof, but down low near the floor and close to the centre-line of the boat. If you read the instructions on installation you will see that they will also give recommendations on proximity to metal, etc.
 
Its a Simrad Precision 9 compass. How on an aluminum boat do you avoid being near metal objects? I could mount it on the side of the cab as well but at best it'll be 4" away from the boat...maybe I should call Simrad.
 
by metal he means ferrous metals, anything with a magnetic field. aluminum is non magnetic and ok. do the magnetic field app thing as i suggested in a prior post. Howzer is right though that for a device that is compass only (mine is a Point1 which also does gps, so needs a clear view of the sky) it should be as close to the center roll as possible. my understanding of the precision 9 is that it is not a GPS and as such, you should mount it inside somewhere as low as possible. this is where it gets tricky with magnetic fields though. keeps speakers, other electronics and anything made of Steel away from it.
 
If you put a stainless arch on the roof the wires are all run down the inside of the arch tubing and through the roof. Either way cut the connectors off closer to the head units where the joints will be away from moisture. I cut mine so the joints end up inside my fuse box area behind my helm. I then get Greg down at Anchor Marine to solder them all up and heat shrink them. I can do basic soldering but prefer someone good at it to do clusters of 6-8 small wires with plastic sheathes etc. Never had any wiring issues doing this.
 
Hi Waterwolf

I recommend you don't cut the wire on your radar or anything else just drill the hole and fill it with sicaflex I've done this and no water will get in there should be a little stainless cover that you put over the wire and hole fill the whole thing with sicaflex or 4200 those silicons can be removed if needed. If you use 5200 it's never coming out !!! I prefer sicaflex it's seals really really well and can be removed if you need to. Good luck

Tight lines
Billydoo
 
Also if you don't know when useing silicon like 4200 or sicaflex put it on then wet your finger is spit or water and you can smooth it out or shape the silicon so it will look good. It can be manipulated
 
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