Problem running cable down mast.

[donncha]

We are currently re-wiring the whole boat and are fitting a new masthead tricolour. Mast is currently horizontal. There are no wires currently running down the inside of the mast and all halyards are external, the halyard were at one stage internal I believe. Every time I attempt to thread the stiff plastic line (belongs to the electrician) down the mast, or up, I encounter something blocking me after about a foot. The electrician thinks it may be some sort of polystyrene, he recommended pouring acetone into the mast to dissolve it. Any suggestions?

 

[wooslehunter]

To find out what it is, take the mast foot off & shine a torch up. I had the same & had a load of foam stuffed around 4 feet up from the foot. A hook made from a coat hanger taped to an ali tube plus a load of swearing (essential for a good job) managed to get enough out to allow me to get a cable puller through.

 

[Odile]

I've just rewired a 10m mast. Take the head off and you will proabably see a conduit tube. Push a length of straightened fencing wire down and pull through. Works fine. Not original, from a psot on this site.

 

[mormargh]

Don't know how old your mast is, but have heard of expanding foam being used in the past to prevent cables slapping around inside. If conduit trick does not work, could possibly run cable down a cap shroud, as with wooden masts.

 

[William_H]

You need a rod of steel perhaps 6mm in diameter 1 metre long. Something stiff enough so you can push hard or hit it to break its way through the foam or whatever. Obviously you need to be able to push hard in line not be trying to feed the wire around a corner.

Drill a hole through the rod end so you can attach a string (or maybe tape a string to the rod) so when it breaks through the blockage you can tip the mast and shake it to get the rod to slide up to the top of the mast (pulling the string)where you can reach it. Hopefully there is only one blockage near the base.

The foam will be of use in stopping the wires from slapping inside.

good luck olewill

 

[PBooth]

My mast is filled with polystyrene, not poured in, but shaped blocks inserted when it was built. the polystyrene has a semi-circular groove along the front edge, which with the shape of the front of the mast makes a circular 'conduit' down the front of the mast for wiring. I rewired the mast last year and ended up taking off the mast foot casting to get good access and used an electricians 'fish tape' like you have. I did run the radar cable down the outside of the mast, it would have been a struggle to get that size of cable down inside. I would avoid trying to dissolve the foam with acetone, it is there to add strength, taking off the mast foot is just a case of drilling out four rivets.