Joining thin wires

Sinc

Sinc

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How do the experts connect thin wires such as those in NMEA cable or compass bulbs for instance. At the moment I use ordinary screw down terminal strip connections but I can't believe this is best practice.
I've searched the net for connectors without success.
Any thoughts
 
For truly 'in-line' connections I use solder and adhesive lined heatshrink and try to secure the joint to something solid.

But I avoid such connections as much as I can, I guess I treat them as extending the leads rather than making a connection if you see what I mean. I make normal connections to busbars or distribution points with crimped terminals. I have an irrational hatred of chocky-block having seen some obscene installations.
 
whipper_snapper said:
For truly 'in-line' connections I use solder and adhesive lined heatshrink and try to secure the joint to something solid.
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That's how I do it. I expect a torrent of responses to say the solder creates a brittle point in the connection, but I've never had one fail. In any case, all types of connection involve a mechanical transition from solid connector to flexible conductor.
 
Me too. If you use adhesive lined heatshrink then you're not relying on the solder for its mechanical strength anyway.
If you want to put further strain relief in, then lay the wires together in the same direction then twist them together, not just the bared metal but the insulated part as well, then solder and cap with heatshrink. More difficult to make truly waterproof though, and not as easy to thread through a conduit or whatever.
 
These are signal cables, rather than power cables. So, it is essential that there is a good electrical connection, to be certain that there is no loss or distortion of the signal.

Solder and shrink-wrap would be the norm, I would think - the other staple of electronics, wire-wrapping, is probably not suitable for use in the usual tight spaces of a boat. Mechanical connections may well introduce signal distortions, caused by point contacts between surfaces that will certainly get oxide layers on them pretty quickly even if they are clean to start with.

Soldered connections must be good, with no dry joints. And as others have said, the soldered joint should not be relied upon for mechanical strength; it should be supported mechanically in other ways.

Connections to plugs or sockets will of course be soldered, with mechanical support of the cable .
 
SlimRick said:
I use the gel filled connectors - BT use them for their jointing. If you PM me your address I'll pop a few in the post to you.
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You beat me to it. I was walking along street across from my home and saw a tupperware box - full of gel-filled connectors.
I have no idea who could have left it there so I took 'em home to prevent a child accidentally mistaking them for sweeties.
 
Have to admit, my NMEA connections are choc-blocks inside small plastic boxes. I'm sure there are better ways of doing it, but I don't think this one is actually bad.

Pete
 
The other methods described here are fine. But get rid of the screw connectors asap. They have no place on a boat, or car for that matter. You will get problems.
 
Thanks Guys.
Never thought of googling 'gel filled connectors'
I was trying silly things like 'join thin wire' and 'small crimp connectors'
:D
 
I like soldered connections for permanence, however, for the NMEA spaghetti junction, I like to be able to modify/upgrade configurations, so I use a 'chocolate block' on a nice high and dry bulkhead, and leave plenty of slack on the wiring. Not neat, but effective.
I also keep an updated drawing of all the NMEA wiring and particpants in the maintenance folder.
 
Behind the instrument panel I've crimped pins onto the ends which go into a long chocblock screwed to a piece of ply and stuck onto the hull. Elsewhere (e.g. the connection between the short wires from the at-helm chartplotter to the long cables I run back to the instrument panel) are the little gel filled ones.

Advantages of the non-sealed (ie chocblock or similar) solution (where dry and practical) are ease of debugging and ease of adding in an additional "listener" to one of your nmea talkers.
 
The small jelly filled connectors are OK and very easy to use but bear in mind they are designed for solid conductors not the multi stranded stuff used to transmit NMEA data and may damage a few of the strands. To extend data cable use tinned multi strand shielded twisted pair cable of between 24 & 28 AWG and connect either at a barrier strip using mini crimp ring connectors and adhesive lined heat shrink or for in line connections use mini ferule crimps, again with adhesive lined heat shrink. If you do solder (effectively turning the multi strand into solid conductor) then make sure there is support on each side of the joint to help prevent vibration fracture.
 
I don't trust the gel filled 3M connectors - a bit too close to scotch blocks for me!

Solder joints are frowned upon now and on the NMEA course I did the only approved method is to use crimp connectors, I use the ones with the glue heatshrink ends - I believe that this gives the best possible reliable joint - we also use exclusively marine grade tinned cable. The only thing that can go wrong is if the wrong crimping tool is used.

(I have never had a problem with soldered joints either - especially with glue heatshrink over the top!)
 
Cookee said:
I don't trust the gel filled 3M connectors - a bit too close to scotch blocks for me!
Click to expand...

I've seen these used outside, at the top of a telegraph pole exposed to coastal winds & rain on Anglesey. Some of them have been there for 20 years and the connection is still excellent - I'm more than happy to use them on my boat :)

Edited to add: There was a batch of more rectangular shaped ones that BT used to use that had a tendency to undo themselves after a few years, so I'd be wary of those.
 
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