Masthead Light Wire

[hurley]

Hi

I need to replace the masthead light wire. My mast is 10 meters long.

The chandlers are wanting to charge £3.00 per meter which seems really expensive to me. I expect I could get a "suitable" alternative from B&Q for a fraction of the cost, but wanted to ask if anyone knows a specific rating etc that I should use.

I need to try and keep the twin core cable as thin as possible as the apertures on the mast a pretty small.

Thanks in advance for your advice

Regards Nick

 

[hurley]

Previous to my earlier post, could I just use an old 240 volt wire taken from my old electric lawnmower. Its twin core and thin enough. ???

 

[PBooth]

Hi, try a local auto electrician, they will have some twin sheathed cable 0.75mmsq will be fine or try Maplins or CPC. Someone no doubt will say 'you must use marine tinned cable' which costs many times what automotive cable does. My boat is wired totally in auto cable and its fine.

Peter

 

[VicS]

[ QUOTE ]
Someone no doubt will say 'you must use marine tinned cable'

[/ QUOTE ] You must use marine tinned cable.


But my boat is wired with ordinary domestic stuff and is all OK 30 years on. I coat the wire ends with some silicone grease.

 

[ebbtide]

Why not take this opportunity to replace with THREE-core cable? That will enable you to add a masthead tricolor to the allround white, surely a bonus on a small yacht where we're so easily unseen.

 

[Boathook]

Use the biggest cross sectional area wire you can. The voltage drop on the 10m in the mast and the rest round the boat does make a difference to the brightness. I rewired mine recently and used 2.5mm 3 core multi strand and coated the ends with silicone. The old stuff removed was 30 years old and 3 core multi strand ...........
PS I only renewed as I did not have enough slack to fit into the new masthead light.

 

[William_H]

I would suggest 3 squid per metre of 4mm cross section wire is absurd. I am looking at an oz catalogue with exactly the wire you want for 1 squid per metre. www.biasboating.com.au or www.whitworths.com.au
However that is for the preferred wire tinned twin reasonably heavy.

You can use what ever you want almost. Non tinned wire will corrode ad be almost impossible to reterminate after a few years but may keep on doing the job. Wire that is too light will give a volt drop which means the light is not as bright as it should be. Your old lawn mower cable may be all right provided it is protected by a suitable fuse ie 5 amp.

So as with so many things you can do it right or do it rough. You take your choice and accept the consequences. After all we don't all drive around in Rolls Royces because we insist on the best. On the other hand to have the best in cable is not that expensive or at least it shouldn't be. good luck olewill

 

[TheBoatman]

Basic answer ~ Yes.

I use standard off the shelf domestic 0.75mm sq twin & earth because I run a tricolour plus and all round white. I don't bother with marine grade tinned wire because of the cost and I can see little or no advantage to paying huge prices just because it has "marine" stamped on it.
What I do is, I don't solder the connections ~ I use special electrical crimps on the terminal ends and I always make sure that the cable outlet from the light fitting is well sealed with silicone and I tape the light fitting with self-amalgamating tape, i.e. no water can get in!!!

I stress that this is what I do, I've no doubt on this subject other members will have a different opinion!

Peter.

 

[Anthony]

1) please dont use 3 core thereby having 2 positives and 1 negative connection, all wiring should be equally balanced.

2) regular cable will corrode over time, if you have ever tried to reconnect old corroded cable to a new replacement light fitting then you would do it right the first time and use tinned cable.

3) for a 10m mast use at least 2.5mm, 0.75 is very small if you do the calculations.

Anthony

 

[TheBoatman]

Anthony
I've successfully used standard 3-core 0.75mm cable for masthead lighting over the past 20 years.

[ QUOTE ]
2 positives and 1 negative connection, all wiring should be equally balanced.


[/ QUOTE ]

I use 1 positive for the tricolour and 1 for the all round white ~ the two are never used at the same time, therefore I only use 1 pos & 1 neg at anytime, i.e. I've got them balanced?

[ QUOTE ]
regular cable will corrode over time

[/ QUOTE ]

Yup your right all cables will corrode given enough time. What I'm saying is that standard cable will corrode nearly, but not quite as fast as tinned type ~ why waste the money. Just allow some extra slack in your average standard cable and re-make the ends every couple of years!!

[ QUOTE ]
for a 10m mast use at least 2.5mm,

[/ QUOTE ]

I can't argue with that because the greater the cross section of the cable the lower the power loss ~ however I have a 10+ mtr mast and I've found that my 0.75mm cable still shows a bright enough light that conforms with the ColRegs ~ you choose!

Peter.

 

[Anthony]

If I was to put tinned cable anywhere it would be in the mast, as its typically the one of the most awkward place to check / replace. In the general scheme of things 2.5mm2 tinned cable is not very expensive compared to say the usual argument of whether to use tinned battery cable, whos cost can soon get very expensive. It is also open to alot of corrosion compared to most cable that remains inside the hull in the relative dry.

Yes .75mm cable will work, its a question of performance. I am not going to type the calculations all out here, but basically the voltage drop is outside the accepted standards.

It is generally a performance rather than a crtitical safety matter, althgough that said if all I have at sea for someone to see me at night is a single bulb, then I would want to get it every conceivable chance to shine as brightly as it was intended to.

As I have stated before on posts, people come on here looking for help, I and others give our help as best we see it. Its then up to the induvidual to balance all that information and make the decision that best suits them.

Anthony

 

[TheBoatman]

Anthony

[ QUOTE ]
I and others give our help as best we see it. Its then up to the individual to balance all that information and make the decision that best suits them.


[/ QUOTE ]

I agree wholeheartedly!

Peter.