Foam filled mast

[2222222]

Anyone know what to do about running new cables thru a foam filled mast? I think that only the first couple of metres are foamed and the cables are running thrtu a conduit. Just dig it out somehow?

 

[Norman_E]

If you have the mast down get a piece of pipe (copper tube used in plumbing will do) Cut some coarse saw teeth on one end. Drill through the other end to put a tommy bar through, and use it to drill through the foam. First make sure all existing electric cables are in conduits, otherwise you may damage them. You will need to withdraw your crude tubing "drill" frequently to remove the foam packed inside it.
I have never done this to a mast but used a similar technique to go through styrofoam underfloor insulation. I have also used a steel slug on the end of a thinner rod, with the steel heated by a blowlamp. It made a lovely neat hole, but I would not reccommend that method inside the mast.

 

[2222222]

Makes sense. Thanks. Not sure why they filled 'em with foam in the first place. I ca'nt see any advantage as the cables are run thru a conduit anyway so it ca'nt be to stop cable slap in the mast. Ho hum

 

[kandoma]

masts should be "watertight" in a rollover situation. If the mast fills up fast when submerged, then the boat may never roll back.

Peter

 

[Avocet]

I made the mistake of squirting builder's foam into Avocet's mast once to shut the cables up. After all, I thought, "what could possibly go wrong with a cable"?

That very winter, someone caught the end of it while on trestles in the boatyard and broke the VHF antenna. It was then that I realised what a mistke I'd made! I used lengths of 1" 16 SWG steel tube and joined the sections together as I got further up the mast like a set of chimney sweep's brushes. In the top I mounted a sort of drain auger claw and then I twisted the bottom with a tommy bar. It took me about 3 weekends to get to the top of the mast! Naturally, I ended up replacing all the wires (I wrecked them with the auger) but I can recommend three large cable ties at about 120 degrees to each other round the bundle of cables to stop them slapping the inside of the mast in future!

 

[SailingDoc]

I considered foam to stop the cable slap - but realised I might run into the same problems you've had. Instead, with the bottom of the mast off, I slid lengths of pipe 15mm insulation along the cables (which are not in conduit), taping each one to the next as they went in, hopefully to facilitate removal if that becomes necessary.

Brian

 

[2222222]

i had considered the pipe insulation trick. Thanks.

 

[2222222]

it's a pig of a job alright. Thanks.

 

[2222222]

good point.