Fixing an electrical conduit inside my mast?

[Trevj]

Can anyone please explain how I can:

a) Securely fix an electrical conduit to carry my vhf coax. and mast-head light wiring to the inside my mast,
or.
b) Suggest any other method of setting the wiring in the mast without rattling or fouling the internal halyards and topping-lift.

The mast section does not have a built in conduit nor one of those little "T" extrusions over which a split conduit may be threaded.
The mast is off the boat at the minute while I am refurbishing her.

Thanks in advance & Regards
Trev

 

[oldharry]

Presumably its the rattling of the cables thats the problem? I have managed to cure this every time by securing the cables about every three feet with the longest ratchet cable ties I can find. The tails are arranged so that they are roughly 120 degrees to each other, so that the cables are held permanently sprung away from the mast wall, and never rattle again.

The only prob is if you need to do a rewire, the whole bundle has to come out again! (I am faced with this as some thieving *** cut my VHF aerial off the day I took the mast down last autumn.....)

 

[machurley22]

I've just done the cable tie trick (believe it was mentioned in PBO a year or three back) for a complete re-wire - VHF, tri-colour and a combined steaming/deck light. Can't report on it's effectiveness yet though since the mast still has to go back up!

Dave

 

[Salty John]

The most permanent way is to mark the conduit with a straight line along its length. Lay the conduit on the mast, in the position it will be inside the mast, so that the line is exactly 180 degrees from the mast surface and securely tape the conduit in position. Drill right through the conduit and the mast, keep the drill as close to perpendicular as you can manage. Place the conduit inside the mast. Pop rivet the lower end of the conduit to the mast, you should be able to hold the conduit against the inside mast surface at the base to get this first rivet in. Form a stiff piece of wire into a hook. Push the hook through the next rivet hole and turn it so it grasps the conduit. Pull the conduit tight against the mast while you pop rivet through the next hole along. Move the hook to the next hole, pop rivet through the adjacent hole, and so on up the mast. I'm sure you get the idea. This system gives a good installation with no chance of your halyards chafing or snagging the cables. The long-tailed cable tie method is easier but not quite as certain of success.
Use RG8X cable for your VHF if the total run is up to 15m, RG8U if longer. Get the best VHF antenna you can afford, your radio is only as good as the antenna system that supports it; get one with a mast head PL259 coupling so you can take the antenna home when the mast is down so no-one can steal it! Put rubber grommets at entrance and exit holes, and drip loops, to avoid water getting into the mast.
Let us know how you get on.

 

[doug748]

I once fitted a 1" plastic water pipe inside a mast and it worked very well. I angled the mast so the tube lay in the position I wanted, then drilled a series of 1/8" holes for pop rivets. Of course the pipe moved away form the drill and you have to fiddle a support behind it in places; where it was really difficult I heated up a piece of mind steel rod and burned a hole through.
Thread your wires through using a length of rigging wire as a "mouse" Brian.

 

[PuffTheMagicDragon]

An easier and (IMHO) neater way is to secure the length plastic pipe by drilling 6mm holes roughly every metre or so through the bottom of the luff groove. Then poke the nozzle of a spray can through and give a small burst of foam. This will expand enough to hold the conduit in place. Do not use tape to join the lengths of tube; use a proper pvc jointing cement - the type that welds the plastic. That way you will still be able to withdraw the tube without leaving a part of it halfway up the mast.
It worked for me. (But my halliards are external. I don't know about yours.)

Fair Winds!

 

[Colinl]

http://lena.invader.port5.com/mast_conduit.html


Have a look here a couple of pictures plus an explanation


Cheers


Colin