Cutting inspection "hole" in mast - possible, or downright stupid?

[Quandary]

A small hole or slot not more than about 10-15% of the mast width should not weaken it, it will be massively over strength near the ends where the bending moment is small. Then a bit of poking about with a bent wire coat hanger should allow the offending wire to be identified and part extracted and a few bits of sticky tape to attach it to another or the inside wall should silence it.
Though I do like the simplicity of Bikedafts suggestion of drilling a 20mm, hole and pouring in some eps packing lumps or beads (bean bag filling). If you do this it will migrate when the mast is horizontal but should fall back in to place when raised.

 

[Thistle]

Would this foolishly/dangerously weaken the mast?

Any ideas/suggestions of how to do it, assuming it would be safe/possible/practical?

Lots of contradictory answers, as you'd expect in a forum such as this. My suggestion would be to start with an email to the mast manufacturer.

 

[LittleSister]

Other potential approaches:

1) Cut a small hole at the height of the 'ting' sound, through which you push the end of a loop of 'stiff tape', then keep feeding in one end of the loop until it is pushing all the wires against the walls of the mast, then 'lock' it at that length.

The 'stiff tape' for a small mast could perhaps be a wide, heavy-duty cable tie type of thing. I am struggling to think of an equivalent larger version, but there must be one. You will want something that is fairly rigid laterally, and semi-flexible lengthways, and with some means of fixing/locking the length once you've pushed the cables to the side. A plate or rubber blind grommet could close the hole afterwards.

2) If with a small hole and endoscope you can identify the offending cable, apply small dollop of rubbery, not too strong, adhesive and hold it against the mast wall until set.

More generally, I think tensioning the wires is a mistake: you are never going to get sufficient tension on a wire/cable of any length to hold it off the walls of the mast, and will likely have more slapping than were the wire left loose with some surplus length.

I do sympathise. An early boat of mine had several unsecured wires in the mast (presumably lacking a conduit), which the slightest movement or swell would rattle/slap- drrrap! - loudly against the inside of the mast, for which the coachroof provided an excellent sounding board. It was one of the worst aspects of an otherwise great boat. Unfortunately, when I demounted the mast I was unable to gain access at either end, and I had to live with the racket it until I sold the boat. My sanity has yet to recover.

 

[Uricanejack]

Be gentle with me I'm thinking of below decks at a convenient height for working access.
Is it possible, without weakening the mast, to cut out a small (maximum "fist" size) inspection hole in the side or front or rear and then have a stout cover-plate well-bolted on to the mast.
My keel stepped mast contains halyards coax-cable and lighting cables. Something is in the wrong place and "tings" right next to my ear when I'm in my bunk. It is infuriating and sleep-depriving.

Leaving aside the obvious such as non-corroding metals/electrolytic action, shape-conforming "plate" etc, would this foolishly/dangerously weaken the mast?

Any ideas/suggestions of how to do it, assuming it would be safe/possible/practical? And if so,at what height between deck-head and cabin sole?


Many thanks for advice, one way and/or the other.

I’m certainly not an expert. However I would think yes on both counts.
My thought if the mast is intended to have a hole in it will have been done right and the mast will be fine,
Even if you enable you to inspect and see the problem, you will probably still have to lift the mast to fix it.
So why take the risk, just get the mast lifted and checked.

 

[Robert Wilson]

I’m certainly not an expert. However I would think yes on both counts.
My thought if the mast is intended to have a hole in it will have been done right and the mast will be fine,
Even if you enable you to inspect and see the problem, you will probably still have to lift the mast to fix it.
So why take the risk, just get the mast lifted and checked.

Yup, right in spades. The noise has not killed me yet, is not endangering the boat (I hope ) and can definitely be fixed at haul-out in 2020.

I am averse to cutting holes anywhere in my boat(s) but if the forumites had said "yeah, no sweat, easy-peasy, go-for-it" I'd have added it to the list for this winter.

One less job to fit in before April '20 :encouragement:

 

[dunedin]

I would not cut extra holes. Apart from anything else, Sod’s law dictates that in cutting the hole the drill and/or cutters will find the cable and damage the cable - one step forward six steps back.
We also have a tapping cable in lower section of mast. But I know the bottom of mast is open and easy to access when mast lifted. Next time it is out I plan to thread heating pipe insulation up the wires from the bottom. Zero chance I am cutting any holes before then.

 

[prv]

if the forumites had said "yeah, no sweat, easy-peasy, go-for-it"

Those of us who've actually done it, did

Pete

 

[Robert Wilson]

Those of us who've actually done it, did

Pete

Some people have all the luck!!
But what about next time, when Sod's Law inflicts itself

 

[William_H]

The mast on my little boat had 2 cut outs in each side of the bottom of the 8m I think about 90mm diameter round deck stepped mast. The cut outs carried turning sheave for jib and main halyards. With some corrosion and replacement of the sheaves extra 3/16 inch holes etc. With a bit of hard sailing over time the mast crumpled bulging out at the side so the mast shortened by about 1cm. My point is that you can get huge forces in column on the base of the mast. No, on a keel stepped mast there is no vertical load support at the deck. So as most people feel despite cut outs and slots in mast sides for halyards the proposed cut out sounds just too much of a risk. ol'will
As a matter of interest I had a mast man weld a collar around the base to recover strength. But latter that mast was lost in a contact with a marker post and later mast has slots for halyard exit at different levels to help keep strength.

 

[Robert Wilson]

Thanks for that. It's the sort of result I feared and I'm definitely not going to tamper with what is an essential part of the boat

 

[gwalarnyacht]

pour in those irritating polystyrene S shaped packaging things, at a hole higher up the mast eg halyard sheave, until pinging stops...

Have you done it? How did it work out?

 

[Graham_Wright]

How about a small hole (or 2 or 3) and injecting expanding form? A little at a time until the noise stops.

 

[PabloPicasso]

Are you cetain the 'ding' is from an internal wire and not some external component?

I'd start with a good look, outside above deck first.

I remmeber being aboard a sailing school boat years ago. A teenager aboard found it great fun, one evening, to ding the mast when he thought no one was looking, and then sit quietly back and watch the skipper's tourmented search.

 

[PaulRainbow]

Chances are, in the 6 years since the OP posted the question, he's either fixed it, sold the boat or got used to the noise

 

[SaltIre]

Chances are, in the 6 years since the OP posted the question, he's either fixed it, sold the boat or got used to the noise

15th Aug 2020:

Robert Wilson

 

[ducked]

A small hole or slot not more than about 10-15% of the mast width should not weaken it, it will be massively over strength near the ends where the bending moment is small. Then a bit of poking about with a bent wire coat hanger should allow the offending wire to be identified and part extracted and a few bits of sticky tape to attach it to another or the inside wall should silence it.
Though I do like the simplicity of Bikedafts suggestion of drilling a 20mm, hole and pouring in some eps packing lumps or beads (bean bag filling). If you do this it will migrate when the mast is horizontal but should fall back in to place when raised.

Might it potentially soak up potentially salty water leading to potential poultice corrosion, potentially potentiated by electrical potentials precipitated by dissimmilar metals?

If you sprayed a sticky goo inside the mast, that might quiet things down a bit, without preventing halyard movement. I have used sunflower oil as a panacea on cars, but in this situation it might grow mould.

Might actually be a job for Waxoyl

 

[bikedaft]

Have you done it? How did it work out?

No we learned to live with it. In addition my dad is now pretty deaf, so does not hear it...

 

[Malish]

An alternative to a soft gasket is to add cable tie spiders at regular intervals.

100% the way to go. Myself, I would avoid some of the earlier suggestions such as foam niblets, and do not be tempted by expanding foam as a quick fix

 

[Caer Urfa]

From a surveying point of view any holes in the main mast will have my alarm bells ringing no matter where they are or size

 

[NormanS]

From a surveying point of view any holes in the main mast will have my alarm bells ringing no matter where they are or size

It would be a strange mast that had no holes in it. Your alarm bells must be ringing incessantly.