boat wiring

[EuanMcKenzie]

I need to run in new cabling for the windscreen wiper as the existing is 30 yrs old and shot and leaking to earth.

It will take a fair bit of current. I know i should use tinned wire but can anyone advise on the right specfor a PVC sheathed cable.

Do you need crimps and if so what is best, soldered terminals or basic crimps?

Can you buy a two core or do you run separate singles. My earth bar is by the fuse box so two core would work best.

What size do you need for say 10 amps?

Where is the best place to buy it? Internet or Glasgow area would suit me.

A load of questions but hopefully someone who already has the T shirt on this one can help me here.

Euan

 

[sarabande]

Merlin have all the answers and do a very quick postal service.

http://www.merlinequipment.com/prod_area.cfm?area_id=37&ind_id=1

 

[jimmcgee]

maplin , great western road glasgow
http://www.maplin.co.uk/module.aspx?ITAG=SPEC&ModuleNo=20666&doy=30m5#spec £1.39 a metre

 

[VicS]

[ QUOTE ]
maplin , great western road glasgow

[/ QUOTE ]

Thats not tinned though

 

[nigelhudson]

Maplin do not appear to sell tinned cable - in fact it is not easy to get hold of unless you go to specialists like Merlin. If you use cable with plain copper cores then be sure to tin the ends with solder before you crimp them. I would also use some extra protection against water ingress around the connectors such as heat-shrink sleeving (also available from Maplins).

 

[macd]

...and if you can stretch to it, do treat yourself to a proper ratcheting crimping tool rather than the cheapo type. The best £22 or so you'll ever spend.

 

[cliff]

Unless I was planning on keeping the boat for a very long time I would not bother with tinned cable.

Melt some vaseline (old aluminium cigar tube is ideal as it is narrow and deep) and dip the ends in it, leaving them for a few minutes to allow the cable to warm up and allow the liquid vaseline to wick up the cable under the insulation. Crimp the ends on before you do this. Clean the outside and apply some shrink tubing. Job done.
--------------------

"Artificial intelligence is no match for natural stupidity"
sailroom <span style="color:red">The place to auction your previously loved boatie bits</span>

 

[PBooth]

I wouldn't tin the wire before crimping, the crimp won't be able to grip the now, solid tinned end of the wire properly. If you must, tin the connection after crimping on the terminal (a properly done crimp won't need soldering as well). I use an anti-corrosive spray (by Wurth) on all my electrical connectons. I'm happy using plain copper automotive cable, use the spray and where possible do connections in the small plastic waterproof jonction boxes from CPC, Maplins etc for a couple of pounds each.

Peter

 

[Jonny_H]

I have just replaced all the battery cables on my boat and got a local mechanic to solder the new terminals onto the wire - it forms a much better joint than crimping if done properly (Crimping crushes the cable and leaves small gaps - solder does neither of these).
If you do decide to crimp use a proper tool or get them hydraulically pressed - the cables we took of our batteries had been crimped with mole grips and a hammer (or so it appears) by the previous owner, and in many cases you could simply pull the cable out of the crimped terminal with bare hands - not very safe!

Jonny

 

[tangofour]

Soldering connections is not always a good solution. The stiffer joint that results, is prone to breakage when subjected to vibration.

 

[Scarboroughsloop]

A correctly crimped terminal will not leave air gaps and is actually gas tight. However correct crimping tools are not particularly cheap! I beleive tinned cable with a crimped connection is best - always ready to be persuaded differently though!

 

[VictorII]

On a boat as in all environments with lots of vibration, soldering is not a good solution. I am myself a trained electronics mechanic and all connections on the boat are crimped properly and then protected with heat-shrink sleeves, and spray or vaseline. I would never trust in soldering them even though I have all the right tools.

The danger lies in the solder heating up when the connection suffers from fatigue, resulting in sudden failure. In a crimped terminal any failure will be gradual from breaking strands. When connecting engine or alternator, sudden failure can be extremely hazardous. Breaking of strands can (and should) be checked, for instance annually. In hard to reach places, you can even do this "blind", by feeling the wire - once properly disconnected from the battery, of course.

 

[pappaecho]

I always believed the tinned wire philosophy, until my 29 year old Evasion which has crimped untinned wiring loom, which still works fine. The later (and bodged) additions did not work fine.
I replaced this secondary looms with new crimped and so far so good

 

[rhumlady]

Soldering prior to crimping will cause problems as the solder creeps when under pressure of the crimp. The joint will be loose after a period of use. This also happens with screw connections and plugs and sockets.

 

[st599]

[ QUOTE ]
Can you buy a two core or do you run separate singles. My earth bar is by the fuse box so two core would work best.

What size do you need for say 10 amps?


[/ QUOTE ]

The cable need to be de-rated in accordance with the Wiring Regs for location and number of conductors in the vicinity and correctly fused. Not something to be guessed at.

 

[whipper_snapper]

Never rely on solder alone. A properly done crimp is perfectly good by itself. I invariably solder after crimping (never before) and then apply adhesive lined heatshrink. It is true that soldering creates a hard spot in the wire which is more vulnerable to fracture, but personally I accept that as the price of an electrically better connection. The heatshrink gives a lot of additional support and I have never had one fail.

 

[halcyon]

In the 80's and 90's when I was supplying the production yards with switch panels, we went on to solder joints for attachment on panel. This was at the time on a cost / production through put factor. Based on around 5.000 panels, and 150,000 joints over a 20 year time scale, I have yet to come across a fault. Over the same time scale I have come across many faults with crimped terminals, not so much from crimping, but metal fatigue at the terminal fixing to the switch. During that time we also used tri-rated swtich gear cable, which is not tinned, for power cabling, for signal cables we used tinned wire. I have found some power cables black, but some as bright as new in the same harness, but neither have caused a big problem.
In all cases the cables were cable tied, and fixed to avoid movement.

But we never soldered before crimping, and I would strongly advise not to.

I have found the big problem was the use of cheap switches, circiut breakers, fuses ets, not how you connect them up.

Brian

 

[EuanMcKenzie]

thanks for all your advice. The summary of which seems to be spend the money on the right crimping tool and make sure the joint is sealed and it will be someone elses problem in time to come!

Another job for the list

Euan