properly splicing wires

[JHZR2]

Hi,

Im doing a bit of audio istallation in my 91 BMW, and so I need to do some wire splicing.

Ive seen two main varieties, tin the wire, twist the tinned wires, and then re-solder tight; and the other being to mesh the untinned wire strands, and then add solder to the twisted wire strands to make them tight together.

Which is right? Ive done both, and have had both be correct enough to have an essentially zero ohm added resistance, per my fluke multimeter.

Also, is it worthwhile to tin the wires if they are being put into a crimp connector? It seems to me that this helps to make better connections.

Thanks,

JMH

 

[Pablo]

Get some solder shrink sleeving. It's used for space reliable hardware.

I am not a crimp fan at all.

 

[alreadygone]

If you're gonna get out the soldering iron, either of your first mentioned methods beats crimping. First slide a piece of heat shrink over one of the wires though.

Bob

 

[Tempest]

I used to work in a wire harness factory for a few years that made parts for slot machines. Either method of solder will work. When we had to do it, we simply soldered the wires side by side (like a butt joint), and never had problems. As said above, put some heat shrink over one wire first, solder, then use a heat gun to constrict the shrink.

Crimping is very reliable if you have one of the fancy cam crimpers that limit the pressure for you (we used specialized press machines for production work). If all you have is the cheapo pliers that just smash the lug, forget it.

 

[chas3]

for solid wire, i use a western union splice (and solder it).

for smaller gauge stranded i just tin both ends and then overlap the tinned ends and solder them together.

for bigger gauges, the lap joint would be kind of bulky, so i would intertwine the wires and then solder. big means like 10.

 

[Russell]

what is "solder srink sleeving"? Is this different from just shrink tube/sleeving you can get just about anywhere?

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Get some solder shrink sleeving. It's used for space reliable hardware.

I am not a crimp fan at all.

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[Pablo]

Quote:

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what is "solder srink sleeving"? Is this different from just shrink tube/sleeving you can get just about anywhere?

Quote:

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Get some solder shrink sleeving. It's used for space reliable hardware.

I am not a crimp fan at all.

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They be this

 

[williar]

I was told to never depend on solder for the mechanical strength of the connection. Thus, always twist the wires together first, back over the wires with the ends of the twisted wires pointing in opposite directions. Shrink tubing is much better, and neater, than tape for insulation. I'm not familiar with "solder shrink sleeving".

 

[DriveHard]

Best electrical connection would be to twist the two bare wires together first...then solder.

 

[Pablo]

See my link - I'm not familiar with the brand I googled - looks like China Khrap - but the description is clear enough and the picture is adequate. In the butt splice solder shrink sleeve connectors the wires go in from each end and either mesh the wire strands or overlap tinned wire. Then the splice is heated – solder reflows, x-linked shrink sleeve shrinks down, and adhesive band on each side is activated. We have ohm-ed and pull tested these for years. Extremely reliable, idiot proof, strong and low resistance. Many (50+, maybe 100) satellites in space right now have these.

 

[Tempest]

That's a pretty neat gizmo Pablo! We never had to use anything that fancy since they don't launch slot machines into orbit...

 

[Master ACiD]

im also not a fan of crimp connectors. but i do take crimp connectors and solder them to the ends of wire if i need that sort or wire end.

i recently made a new ground cable for my cars engine. i has a length of 2 foot 100 strand oxygen free 2 gauge copper cable laying around from when i installed my audio amplifier. i went to lowes and bought a pair of crimp on copper terminal ends so i can bolt the ground wire to the engine and the chassis.
i slid on 2 lengths of heat shink first of all. (dont forget the heatshrink!). next i put the terminal ends in the bench vise and heated them up with a propane torch. while that was warming up i stuck each end of the copper wire in the end pieces so they would get nice and hot as well. when everything was nice and hot i apply solder to the end pieces and it got wicked right down into the bottom and coated the wire too so i think its a good connection. you know its a good sonnection when you apply solder and it just disappears. but just to be sure i grabbed the extremly hot pieces with my battery cable crimping tool and gave it a good squeeze. so now i have a cable thats got a pressure (crimp) connection as well as a glue (solder) connection. finally slide the heatshrink on while its still warm and it sucks right down to perfection.

so whenever possible i like to solder and crimp. the best of both worlds. but if its just some speaker wires or something small, ill just solder and heatshink it. my own speaker wires are all soldered and shrinked, even the ones which require crimp on connectors (like the subwoofer sound cable and amplifier power cables)

 

[moribundman]

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im also not a fan of crimp connectors. but i do take crimp connectors and solder them to the ends of wire if i need that sort or wire end.

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I use crimp connectors, solder the wire to the connector, let the connector cool, then crimp the crimp tabs to the wire's insulation.

When splicing, I use the butt soldering method for small gauge wires. I use of course heat shrink tubing or more and more often cold shrink tape for convenience.

 

[Papa Bear]

marrettes...

 

[moribundman]

I've never ever used a wire nut.

 

[Pablo]

I've used plenty of wire nuts for house wiring. They actually work fine, but there is proper install and bad install....like anything. Mori - What do use for junction boxes, switches, adding outlets and stuff? Solder and shrink sleeve?

 

[moribundman]

In that case I call an electrician. The wiring in American homes that I see is done so poorly I refuse to touch it. My wiring efforts are limited to hobby projects and my car.

 

[Pablo]

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The wiring in American homes that I see is done so poorly I refuse to touch it.

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I can't argue with you there. I once had a home with a "garage conversion" - some reprobate candidate from Thor's School of Electrical Geniuses had alternated his hot and neutral through the garage at each outlet (never assume an N in a single phase home wiring set up doesn’t have potential!). Not sure where he picked up this “hot” tip. I knew it before I bought the house and leveraged his lack ‘o permits, etc for a good price. Fixed all his stuff for low $, sold house for good gain. But I’ve seen all sorts of nasty stuff, even in my latest few houses - done by the original builder with electricians trained on the run from the border. My dad was an electrical contractor, so I can handle most normal stuff safely………famous last words.

 

[moribundman]

The wiring at my current place looks like something from a Russian space station.

I'll have to take a picture of the phone wiring in the basement for you guys. It's indescribable. The PacBell tech almost started crying when he had finally managed to get my DSL line working.

 

[TallPaul]

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The wiring in American homes that I see is done so poorly I refuse to touch it.

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Which is why I refuse to call an electrician. I know if I do it myself it will be done right or else I have nobody else to blame. Why pay someone to do a shoddy job when I can at least try to do a good job? The one time I called in an electrician, and a supposedly reputable one, we got ripped off and the guys didn't know what they were doing. Had to call them back out to fix what they screwed up. Resulted in a letter writing campaign and involved the BBB. Finally got a hundred dollars back but still felt overcharged.

In my new-to-me used motorhome we were running the air con off the generator (5500 watt) and started smelling burned plastic. Opened the electrical compartment and found where the #10 solid wire from the gen-set connected to the (presumably #10) stranded wire leading to the circuit box, the wire nut was melting on the hot side. Would eventually have shorted on the box. It appeared that the connection was very poor. I re-stripped and put a new wire nut, taking advice from someone on the IRV2.com site to make sure the stranded wire extended about 1/16" farther than the solid. Ran the gen for several hours on a 90 F day and no excessive heat anymore. Also taped them for extra security. Just think if some boneheaded electrician did a poor connection like that in your wall?