How to Crimp Little, Tiny Wires

[skipmac]

OK. Right up there with anchors and guns, how to crimp/connect a wire.

Have followed all the threads on crimping but unless I overlooked it, have not seen this question addressed.

I am finding more and more electrical devices (like LED light fixtures) with wire leads of very small wire. Usually unmarked but I'm guessing AWG 25-30? So what is the best way to connect this to a larger gauge wire that feeds in from my panel or wiring harness? The smallest I usually have coming off the panel might be 16-18 gauge which works fine with a standard crimp fitting but will not hold the tiny wires attached to the device.

I will now make a public confession to doing some of these in a way that is probably wrong. If the wire on the device is a little larger say in the range of 20-22 gauge I sometimes strip a longer section, double over the wire to make a larger bundle so it will hold in the crimp. For really small wire I have again stripped a longer section of the wire and inserted it all the way through the butt connector so when I crimped the larger wire from the panel it also captured the small wire for the device.

When I did computer work I used mini-pins for data cables but they're a bit of a pain and don't directly connect to a regular crimp fitting. I have seen some uninsulated spade terminals for smallish wire but haven't seen one for the really small stuff. Would prefer using butt connectors anyway that are easier to heat shrink and seal.

Do not plan to make solder joints. However I don't expect expressing that preference will prevent recommendations to the contrary.

[DeepFrz]

What you have been doing is perfectly acceptable as long as you get a good solid crimp. Cover with heat shrink.

[djmarchand]

You can use the pink connectors. Double the small wire so it will be secured and cut off half of the strands of the 14 ga wire.

David

[Lake-Effect]

Originally Posted by skipmac

OK. Right up there with anchors and guns, how to crimp/connect a wire.



I will now make a public confession to doing some of these in a way that is probably wrong. If the wire on the device is a little larger say in the range of 20-22 gauge I sometimes strip a longer section, double over the wire to make a larger bundle so it will hold in the crimp. For really small wire I have again stripped a longer section of the wire and inserted it all the way through the butt connector so when I crimped the larger wire from the panel it also captured the small wire for the device.

You can get lugs for AWG#22-18 (red insulator). When the wire's even smaller I have done the doubling thing too. If the wire wasn't nicked while stripping, and the doubled wire is held firmly enough when crimped, I think it's OK.

The "long-strip and poke through" is also OK.

I personally like this sort of splice connector:



-one less crimp than a butt splice, and easy to seal by squirting goo into the end after crimping.


Other options, when joining the small wire to something larger:
- terminal strip and right-sized lugs, or a compression-type terminal-strip
- automotive-type 2-pin connector (eg Molex)

... assuming this will always be accessible

[The Garbone]

I use 3m scotchlocks on my fine wiring. Twist together to provide strain relief then cut off the 2 ends even leaving isulation, crimp on filled scotchlock. They are submersible, quick and pretty much foolproof.

[MarkJ]

Lake Effect does what I do.

It's the NMEA wires and their associated power wires that piss me off.

I twist them together and use a butt plug.... Maybe there's a better word?

It works as well as anything.

The wires are so stupidly small... Only a few hair widths to join or to join onto a proper size wire, or even worse to try to put into a switch panel.

[Cotemar]

Folding the wire over to make it double will work fine.
That’s what I do also.
I do not use a crimp tool on these small connectors thought. I just use a pair of wire cutters to crimp without cutting the connector. I do it twice just a little space apart, so as to leave two small flat crimps.

[Dsanduril]

I generally go the fold over route (and it works fine) but...

If you want to join a really small wire to a 14-18 butt splice, you can get an electrical wire ferrule and crimper (McMaster-Carr) for the really small wires. Crimp a ferrule onto the wire, then put that into the larger butt splice. They're really made for landing on terminal blocks, etc, but also do a good job of increasing the wire diameter. Of course, yet another tool to own

[River Cruiser]

I solder & use heat shrink tubing or the fold over & twist if crimping.

[colemj]

I often find that doubling the wire and crimping causes a strain point on the single thin wire left in the insulation and then it breaks there. So I usually double the wire back against the insulation, put the whole piece into the fitting and crimp - being sure that the crimp wall is on the bare wire itself.

This does not provide a solid cold moulded crimp, but works well for communication wires like NMEA0183 or very low current devices like LED indicator lights.

Mark

[skipmac]

Originally Posted by colemj

I often find that doubling the wire and crimping causes a strain point on the single thin wire left in the insulation and then it breaks there.

That is one of my concerns using this technique although so far the only really small wires I have had to deal with have been in protected spaces with no strain or vibration so hoping breakage won't be a problem.

Originally Posted by colemj

So I usually double the wire back against the insulation, put the whole piece into the fitting and crimp - being sure that the crimp wall is on the bare wire itself.

This does not provide a solid cold moulded crimp, but works well for communication wires like NMEA0183 or very low current devices like LED indicator lights.

Mark

I like this idea. Think I'll try that on a couple of connections.

[skipmac]

Originally Posted by Cotemar

Folding the wire over to make it double will work fine.
That’s what I do also.
I do not use a crimp tool on these small connectors thought. I just use a pair of wire cutters to crimp without cutting the connector. I do it twice just a little space apart, so as to leave two small flat crimps.

Don't know if I could do this with wire cutters without cutting the insulation on the crimp. I have a small pin crimper that I use for this. Not the perfect tool but does work. Just found a new ratchet tool I'm going to try. Not sure what it's actually designed for but it's smaller than an Ancor ratchet crimper but bigger than the pin crimper. May be just the ticket.

[F51]

Originally Posted by skipmac

Just found a new ratchet tool I'm going to try. Not sure what it's actually designed for but it's smaller than an Ancor ratchet crimper but bigger than the pin crimper. May be just the ticket.

Skipmac, please report back when you have tried the new crimper. I doubt I'm the only one who would like to know mfr, model number and vendor if you have success.

[Lake-Effect]

Just so everyone is appraised, some of the stuff we're talking about here would not meet ABYC electrical spec (doing some of this from memory):

- doubling the wire before crimping. I have done it, but only on my own stuff. ABYC would say if that's necessary, you have the wrong size or type of connector
- folding the wire back onto the jacket and crimping on that. It's a compromised crimp, period. It's not the gas-tight metal-on-metal under serious compression that you get from a proper crimp. it could pull apart. It could corrode. I wouldn't do it.
- crimping with sidecutters. Unprofessional. Even the non-ratcheting cheapo crimpers would do a better job than side-cutters.
- soldering. ABYC is not officially against it, but the connection must be physically secure before the soldering; soldering can't be the sole source of mechanical strength. Also, ABYC doesn't accept that a twisted splice in stranded wire (eg Western Union splice) is mechanically acceptable. Given all this, and the fact that soldering also makes a flexible stranded wire into a brittle solid wire at the joint... there's really not much practical application of soldering in the normal course of boat wiring, when you can meet approval from a good crimp connection.

Also, re wire 'thinness', ABYC currently wants power-carrying wiring to be a minimum of AWG#16. This is because of wire strength when pulling, and also from the pre-LED days when most boat DC loads were more than a couple of amps. I'm told they may soon approve thinner wire gauge in proper application (eg NMEA2000 interconnect, LED lighting) if it's in a suitable jacket for pulling.

Last thing - I believe than no connection should ever be intentionally under physical load, so you should plan your wiring so that any connections are accessible and positioned so they never experience physical stress. No connection should ever have repetitive bending stress on it.

[goboatingnow]

I would always use small uninsulated crimps and then heat shrink. Small crimps are readily available from electronic supplies

Dave