Use of "tinned" electrical cable?

[thinwater]

If you are using chock blocks (screw terminals of any sort) in damp areas you can always use boot lace ferrules to seal the insulation. Just sayin'.

 

[thinwater]

Another common forum distortion is over participation by people arguing for perfection at any cost. A visitor would think, for example, that all sailors wear PFDs (lifejackets) 100% of the time, when in fact it is a minority.

We can argue tinned wire and the effects of corrosion on a damp boat over 40 years, but what I am sure of is that both me and the boat will be in the chipper in less than 20 years, so I'm not to concerned about a 40-year fix. 20-years, yes, so I'll use tinned wire in the bilge and for nave lights, and THHN in my nice dry cabin, and suspect both will be going strong in 40 years. Thank you.

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No one responded to the fine vs. medium stranding of non-tinned wire question. I can't tell from the posts which they are talking about.

 

[geem]

If you are using chock blocks (screw terminals of any sort) in damp areas you can always use boot lace ferrules to seal the insulation. Just sayin'.

You can if they fit. I use these with shrink wrap where possible but some LED light fittings are too small to make these connections. There isn't enough space in the fittings.

 

[snowbird30ds]

I recently changed my helm panel and had to modify the volvo wiring, was it tinned? No, but after nearly 40 years it was a bit tarnished.
If you solder the ends of untinned wire it's tinned, the blackening along the length makes no odds unless it corrodes through.

 

[coopec]

That is just not right. If you seek advice in this forum then choose to ignore it then that's fine but don't argue you are right. If you didn't get the advice you wanted you shouldn't have asked. You cannot heat shrink every end terminal on every device. Light fittings often have chocolate block type fittings. There isn't room to add crimp on terminals and heat shrink. These circuits will be susceptible to corrosion if you choose to use none tinned wire. It happened on my previous boat. All wire needed to be stripped out.
If you build your boat and sit in a marina or don't sail in poor weather you may well find you get away with none tinned wire for quite some time. If you have a leak from a hatch, deck fitting, etc and your light fitting gets wet from salt water you will possibly need to strip out your wiring and replace it. This is the kind of thing that does happen. It's why those with many years of cruising experience give you advise to this effect

Have you read my previous comments?

I'll say it again very slowly



Now have you got it?

 

[Stemar]

If you solder the ends of untinned wire it's tinned

True, but have you ever tried to get black wire clean enough for the solder to stick? I have. I don't bother now, I just replace it if it needs soldering.

 

[AngusMcDoon]

If you solder the ends of untinned wire it's tinned, the blackening along the length makes no odds unless it corrodes through.

Soldering wire ends used in mechanically made electrical connections has 2 problems. These are:

1) It creates a hard spot and hinge point that is often unsupported by the wire's insulation. The soldered wire is hard and inflexible and transitions to flexible unsoldered wire usually without support from the insulation. Movement and vibrations will cause bending at this interface eventually leading to fatigue failure. Although crimp connections also have this inflexible to flexible transition, when a crimp is done correctly the insulation is also crimped and supported so that there is no unsupported hinge point.

2) Solder has a high creep rate when mechanically stressed. This can cause joint failure much quicker than 1) above. If you solder a wire end and then make a mechanical connection with it, either crimped or some other kind of squeezed or screw down, the solder is mechanically stressed and slowly starts to deform plastically via creep. This will loosen the connection leading to possible failure, sometimes in only months. In addition it allows oxygen into the contact area initiating corrosion. The tinning on tinned wire is such a thin layer that any creep effect is negligible and crimped/squeezed connections are as good as untinned wire.

In situations where safety is a factor soldered wire ends in connections are explicitly banned. On a boat, you'll most likely get away with it, but have less reliable shorter service life wiring. Crimp and ferrule connections are cheap, quick and reliable and should be used preferentially to anything else.

 

[coopec]

Soldering wire ends used in mechanically made electrical connections has 2 problems. These are:

1) It creates a hard spot and hinge point that is often unsupported by the wire's insulation. The soldered wire is hard and inflexible and transitions to flexible unsoldered wire usually without support from the insulation. Movement and vibrations will cause bending at this interface eventually leading to fatigue failure. Although crimp connections also have this inflexible to flexible transition, when a crimp is done correctly the insulation is also crimped and supported so that there is no unsupported hinge point.

2) Solder has a high creep rate when mechanically stressed. This can cause joint failure much quicker than 1) above. If you solder a wire end and then make a mechanically made connection with it, either crimped or some other kind of squeezed or screw down, the solder is mechanically stressed and slowly starts to deform plastically via creep. This will loosen the connection leading to possible failure, sometimes in only months. In addition it allows oxygen in initiating corrosion. The tinning on tinned wire is such a thin layer that any creep effect is negligible and crimped/squeezed connections are as good as untinned wire.

In situations where safety is a factor soldered wire ends in connections are explicitly banned. On a boat, you'll most likely get away with it, but have less reliable shorted service life wiring. Crimp and ferrule connections are cheap, quick and reliable and should be used preferentially to anything else.

I'm not looking for an argument!

Angus what do you do if you want to connect a cable to a BUS BAR that has grub screws?

0:00 / 25:14 How To Terminate Wires 101 Tutorial. Crimp Solder Shrink [WIRING 101]

 

[AngusMcDoon]

Angus what do you do if you want to connect a cable to a BUS BAR that has grub screws?

Using bootlace ferrules is one possibility. The screw base grinds into the outside of the metal of the ferrule giving a good connection, and the wire strands are protected from breakage inside the ferrule.

A ferrule crimper only costs a tenner on ebay, and a multi-size kit of different sized ferrules another tenner.

You can also use blade crimp terminals if you don't want to buy another crimping tool. The terminals are a bit more per terminal than ferrules. Depends on how many you have to do. These terminals are also more tolerant of multiple insertions and removals than ferrules which get a bit mangled after first use.

With a long blade and double row of grub screws as in your image you can make 2 connections to each wire with these terminals if you want belt and braces. Ferrules only have the length for a single grub screw connection.

On that big common screw at the right hand end use a crimp on ring terminal which will be superior to just wrapping a bare wire round the screw which will have a tendency to squeeze out if screwed down hard.

 

[Sandy]

And I thought anchor threads were controversial!

 

[AngusMcDoon]

And I thought anchor threads were controversial!

No controversy really. It's all standard industrial practice that boils down to only 3 rules...

1) Use cable that is suitable for your application and budget.
2) Use crimp connections wherever possible.
3) Support and protect your wiring.

 

[geem]

No controversy really. It's all standard industrial practice that boils down to only 3 rules...

1) Use cable that is suitable for your application and budget.
2) Use crimp connections wherever possible.
3) Support and protect your wiring.

I would add, use conduit in areas where replacement would be difficult and install draw wires as you never know when you might want to add new wiring.

 

[AngusMcDoon]

I would add, use conduit in areas where replacement would be difficult and install draw wires as you never know when you might want to add new wiring.

Good boat builders do that as standard. On my previous Dragonfly I had trunking with mousing lines through them that didn't have any cables in them but were installed in case of future upgrades.

 

[geem]

I wish my boat did. In 1980 things were a little different

 

[thinwater]

You can if they fit. I use these with shrink wrap where possible but some LED light fittings are too small to make these connections. There isn't enough space in the fittings.
[/QUOT
Those sound like cabin lights, so they are in a dry location.

I'm not looking for an argument!

Angus what do you do if you want to connect a cable to a BUS BAR that has grub screws?

0:00 / 25:14 How To Terminate Wires 101 Tutorial. Crimp Solder Shrink [WIRING 101]

He was not arguing with you he was stating established engineering fact.

a. Don't use bus bars with grub screws with stranded wire. They are designed for solid wire (which cannot use crimp fittings). Same for chock blocks without pressure plates.

b. Crimp on ferrules.

c. Use medium stranded THHN type wire. Not optimal, but the coarser strands better withstand the damamge.

But soldering the ends and inserting those is known to be incorrect.

 

[38mess]

And I thought anchor threads were controversial!

I was just thinking this.
a few people harvest stuff off the net then spout it in here as their own experience which is dangerous. People with real experience are ignored. The trick is to work out who to listen to.

 

[Keith-i]

If you solder the ends of untinned wire it's tinned, the blackening along the length makes no odds unless it corrodes through.

Actually that’s not correct. The ‘blackening’ along a wire does impact its current carrying ability. Maybe not enough to affect a low frequency signal wire from an engine but certainly on something higher current.

 

[Capt Popeye]

I was just thinking this.
a few people harvest stuff off the net then spout it in here as their own experience which is dangerous. People with real experience are ignored. The trick is to work out who to listen to.

Well maybe good advice , BUT , I have never heard anything on these pages , ONLY READ stuff - what am I doing wrong ? {)#

 

[38mess]

Well maybe good advice , BUT , I have never heard anything on these pages , ONLY READ stuff - what am I doing wrong ? {)#

You know what I mean

 

[Capt Popeye]

You know what I mean

Yea I know , t'was only jesting a bit , to make a difference to the conflicting advice given to be read , etc