Soldering vs Crimping

[crazy steve]

I just couldn't stand this anymore...

Every time I read about someone recommending/doing soldered wire connections on a bike or car I cringe. You'll hear guys say 'that's a better connection', but if you look at any factory bike/car harness just try to find any soldered joints that aren't on a circuit board. There's reasons why the factories don't solder and it's not because of cost either.

In the electrical industry, it's been illegal to splice/terminate wires with solder for years; only mechanical means are allowed. Why? Because solder, when subjected to a high heat situaton, will melt. Another issue is the heat needed for soldering destroys the wire's annealing and makes the copper brittle (so now it will break much easier). But, you say, crimp connectors don't have a good record; too many fail. True, but that's not the connectors fault but rather the crimping method that's at fault. With the correct crimp, you can retain both the electrical and mechanical characteristics of the unbroken wire.

The problem is the use of insulated crimps. They're convenient, but the compromises needed to make them work also reduces their reliability in these applications. One thing to keep in mind is that none of the 'generic' wiring connectors you'll find at parts houses were invented for vehicle use; all have been 'adapted' from the electrical industry. There's several problems here...

1. To avoid ruining the insulated sleeve, you don't get a 'full' crimp. The 'standard' insulated crimping tool you'll find nearly everywhere with it's 'football' shaped crimp opening only gives you about a 70% crimp at best. So you've reduced both electrical and mechanical strength. The fix? Use a uninsulated crimp and this type of crimp tool:
http://www.idealindustries.com/prodD...lti-crimp_tool
These feature a 'U' shaped crimp opening and will give you closer to a 100% crimp. These are available from several sources, with Ideal, Klein, and T&B all offering versions. My personal choice is the T&B (the original inventors) as their openings have tighter tolerances, but any will be an improvement over a 'standard' type. These are about $25+/- at most electrical supply stores. Look for them at swap meets/garage sales too; most people don't know what they're for, so you can get them cheap. The one I use the most is probably older than me, has three crimp holes (the newer ones only have two), and has no other functions (no cutter, insulated crimper, etc). It does give a 100% crimp.

2. Insulated crimps don't 'support' the wire insulation. If you look at any factory termination, there's two crimps; one on the copper, and one to the insulation. The insulation is a big part of the wires strength, and failing to 'transfer' any stress from the termination to the insulation can lead to strand failure. You can buy this type of crimp, but they and the special crimp tool are both expensve. Using uninsulated crimps/shrink tube and overlapping the shrink 1/2" to 3/4" onto the insulation will be equal.

3. Insulated crimps aren't sealed; with a 70% crimp and it's open end, there's plenty of places corrosion can get a foothold. As designed, these are only rated for use in dry, vibration-free enviroments with no movement. Not exactly a motorcycle...

Can't find uninsulated crimps? Just cut the plastic sleeves off; that's the difference. A properly crimped, uninsulated splice/termination with shrink tube over it will have all the same qualities as an uncut wire.

Now, before anybody says 'I've been soldering wires on my bike/car/etc for years with no problems!', I'm not going to argue with you. That can work, but either you used a lot of care about where/how you did it, or you've been lucky. This is the right way to do this, that's what I'm saying.

'78E original owner

[trbig]

In the electrical industry, it's been illegal to splice/terminate wires with solder for years;

Hmmm.. All those solder connections on all the weapons systems of all those jets I did that the electronics departments at Mcdonald/Douglas, GE, and Lockheed recommended.

If you do it properly, and use a heat sink to avoid insulation damage and remove the flux.. which is corrosive and the major problem.. you'll be fine. I'm betting you don't see it much on cars because you can mass produce crimped wires much more cheaply and quicker.


Tod

[Larrym]

An Old Connection Revisited

crazy steve,

When you're right you're right. Unfortunately, historically those who were right while everyone else was wrong didn't have their ideas welcomed with open arms. Copernicus? Galileo? Each one was right but that alone wasn't enough to keep things from getting real awkward.

Yeah....lots of folks are not gonna like it when their preferred crimping tools, connectors, and methods are recognized as something made my Fischer Price only suitable for ages 4-6 years. Losing those candy-colored insulators is gonna be a hard sell. It's Fun! It's Easy! And don't it look purty with all those neon bright colors??

Black or Grey glue lined shrink tubing just don't look the same. No dazzle or pop.

It's ok, steve. Keep trying to drag us into the 21'st century even if we go kicking and screaming every step of the way.

Just don't be surprised when instead of you leading us forward, we all band together and try to drag you backwards forcibly.

Some traditions are too important to abandon.

[Geezer]

I could agree with you more. I only use non insulated splices, crimp them with a ratcheting crimper and then insulate them with heat shrink tube.

BTW, I now carry a ratcheting crimper for 24 bucks in case any one needs one.
http://www.oregonmotorcycleparts.com/connectors.html

Geezer

[Ivan]

Well....

Most manufacturers of automobiles, at least the big three, made us crimp and solder on repairs, but yes factory terminals were crimped.

Personally I am partial to those weather tight heatshrink crimp terminals. They are the best of everything right in one package, with the sealing wax included.

I also agree on the proper crimp tool. That makes all the difference.

I really really really hate twist and tape. Anyone who knowingly does that around me risks an ass chewin'.

[crazy steve]

Hmmm.. All those solder connections on all the weapons systems of all those jets I did that the electronics departments at Mcdonald/Douglas, GE, and Lockheed recommended. ...

Tod

You're confusing two different fields; electronics vs electrical. Soldering is standard practice in electronics, but is illegal in electrical, and ill-advised on vehicle electrical.

'78E original owner

[81xsproject]

solder, solder, solder.

[Yard Dogg]

I was on an electrical forum just the other day where there was a discussion about making good solder joints. In electronics, which means pretty much anything that has to do with copper wiring, rosin core solder must be used. The weakening of copper I think your referring to, is when you use an acid based solder, because the acid in the solder continues to eat away the copper at room temperature. The rosin core solder does not. All the factory crimped connections I've ever come across in automotive were crimped and soldered by a press solder machine of some type. I was having trouble making the solder flow over the wire as it ideally should, it just kept rolling off. I had to go purchase some "Lead free solder paste with non corrosive flux" to make the rosin core solder work the way it should. In my experience I've had bad luck with soldering on wiring. I'm not sure if I keep getting crappy batches of rosin wire or what, sometimes it goes great, other times it will not flow into the wires. I usually end up using the not jacket crimps and shrink tube. I prefer solder, cause I think it is a better connection, but crimping and shrink tubes work real well too if I can't get the solder to stick.

[crazy steve]

...The weakening of copper I think your referring to, is when you use an acid based solder, because the acid in the solder continues to eat away the copper at room temperature. The rosin core solder does not...

The type of flux has nothing to do with it. While acid-based flux will eat electrical connections, it's the heat needed to get a good solder joint is what causes the problem.

'78E original owner

[Yard Dogg]

The type of flux has nothing to do with it. While acid-based flux will eat electrical connections, it's the heat needed to get a good solder joint is what causes the problem.

'78E original owner

You've got me thinking now. Honestly I hate soldering, it's a pain in the neck. I usually end up crimping anyway. So I started looking around to see what temperature copper recrystallizes and you should see the ridiculous pages I'm bringing up. It's like trying to read advanced Greek. I think I'll stick to crimping. I can make trustworthy crimps.

[trbig]

You're confusing two different fields; electronics vs electrical. Soldering is standard practice in electronics, but is illegal in electrical

You are the one confused. I was refering to the electrical connections and cannon plugs that are multi-wired ends on bomb racks, missile launchers, guns, etc, as well as other connections on just about everything. You'll have plugs that have male and female pins that you join together, but the back side of those pins will be soldered. I was not refering to circuit boards or electronics. The military uses almost exclusively SOLDERED connections to wires, not crimps. Look under a microscope, and crimping actually damages the wires. Soldering is recommended by all the suppliers who's parts are serviced that I stated as well as many others. You have to take classes to get certified to do this, but a properly tinned and soldered connection is going to be a MUCH better complete connection electrically than a crimp.

Do I crimp wires? Sure.. it's easy and fast, but no, I don't think it is the best alternative.


Tod

[Larrym]

Heretics Must Burn!!

Is this a bad time to mention that I use the ABYC standards for my connections?

American Boat + Yacht Council= Crimp, solder, tinned wire, tinned connector, stress relief, glue lined shrink tubing, and labels??

You gotta see what happens to an unsoldered, store-bought, automotive BUTT splice crimp connection in less than 6 months in a marine environment. Still pretty and blue insulation on the outside.

On the inside it kinda scares me that NATURE (not man) is responsible for that color green and so much of it.

I've seen better connectivity in wire-nuts.

[b.walker5]

Steve, while I agree with your reasoning behind using uninsulated crimp joints, as a registered electrician with over 30 years in the field I'm afraid I dont quite agree with your disdain of soldered joints. In this country the use of solder in the electrical industry isnt illegal and in many cases it provides an electrically better and stronger joint than any crimp is ever going to. We have an AC multiple earthed Neutral (MEN) system with 240V single phase and 400V three phase being the common low voltage supplies. When terminating the main neutral on the Earth/Neutral bus bars in the DB solder lugs are preferred as there is less chance of a high resistance joint causing heat and potential fire. There are many other instances where solder is preferred for the same reason, including underground cable joints, and when equipotential bonding of copper water and lead waste pipes soldering is mandatory. There are, however, some guidelines around the selection and use of solder appropriate for the job in hand, i.e tin/lead and/or silver content. It's worth noting that lead waste pipes havent been used in new housing for years but are commonly encountered in older housing. Copper water pipes are still widely used and is preferred to uPVC and Poly Butynol.

In automotive applications I prefer crimped joints and terminals, and i dont use the insulated crimps 'cause theyre crap even without the insulation, but it's more out of convenience than anything else. Soldered connections in the right application are fine and provide much lower resistance than crimps, but I do accept that in areas subject to movement and vibration extra support may be needed, and it's hard to imagine doing the pickup fix with crimps.

[crazy steve]

Ok, I'll take these in order...

Tod: No, you still are confusing electronics and electrical. Yes, solder is commonly used in the electronics industy, and on more than just circuit boards. And they don't refer to 'Aircraft Electrical', but call it 'Aircraft Electronics'. But in the electrical field, solder connections are illegal 'unless part of an approved assembly', i.e. is a factory assembled item and has a testing lab approval such as UL. If I had a current copy of the NEC, I could quote the pertinent section but what it says is ALL field connections 'shall be made by mechanical means', no exceptions. Any sort of electronic gear I ever installed (fire alarm panels, freq drives, etc) always had mechanical terminal strips for the field wires. And THE big difference between 'electronics' and 'electrical' is the circuit current and available fault currents; where most electronics operate at currents measured in milliamps, that's not the case in electrical circuits. Even a bike battery can deliver 500 short-circuit amps, and that's way more than enough to melt a solder connection. Also keep in mind that on aircraft (particularly military), there's several differences that you won't find anywhere else; these things are routinely removed and/or checked, and I'm sure that one of the checklist items is the integrity of the solder connections. They also use higher strand-count wire, so the wire is much more flexible and much less prone to vibration failure. If we had to have buildings wired and maintained to MilSpec, we'd still be using oil lamps...

Larry: Yeah, marine (particularly salt water) is a very tough environment. The big trick here is sealing the connecton. The reason I don't like solder connections is they break much easier. Like I said, heat makes the copper brittle. Here's a test you can try; put a butt splice on the ends of a piece of wire, soldering just one end. Then put the splices in a vice and bend the wire back-and-forth. I'll guarantee the soldered end will break off in 1/3 or less 'cycles'. Another issue with soldering is once you've damaged the annealing, it corrodes easier (don't ask me why, I just know it does). If I were doing a marine splice, modern 'sealing' type shrink tube should do it. On a termination where you'll still have an 'end' showing, I'd apply a bit of solder to just the exposed end (after crimping) to seal it, then do the shrink. I used to solder too, but after having multiple failures over the years (in every case, the wire broke right at the junction where the annealing was gone) I quit doing it and haven't had one go bad since with a proper crimp.

Butch: I've also been an electrician for over 30 years (third generation to boot! Not that that counts...) and soldered connections have been illegal here for longer than that. Why I don't like them in this use is covered above. But at work, I have seen some old installs that have failed though, and according the engineers I've talked to, they saw enough failures under high-current/high heat conditions that the method was outlawed. The reasoning was a slightly higher-resistance mechanical connection that has a much better chance of surviving high heat is better than a lower-resistance connection that may fail. A lot of it has to do with what kind of overcurrent protection is being used, as here nearly everything is inverse-time circuit breakers which have been known not to properly clear a short. I do know that grounding/bonding is still a bit of a 'black art', as over the years I've seen things that were required at one point become illegal and vice-versa. I'm not going to claim I know why; not even the engineers could always give a clear explanation...

The last thing to come in before I retired was 'fault current' calculations; you had to know the primary fusing at the transformer, it's KVA, and the size and length of the feeders to the service. This determined the RMS 'fault' rating of the breaker (minimum of 10K amps, up to 200K, and not to be confused with amp rating) so in a fault the breaker could clear the short without ionizing internally and maintaining the circuit. I believe you use fuses much more 'down there' and they're actually a better way to clear a problem.

'78E original owner

[crazy steve]

Here's a test you can try; put a butt splice on the ends of a piece of wire, soldering just one end. Then put the splices in a vice and bend the wire back-and-forth. I'll guarantee the soldered end will break off in 1/3 or less 'cycles'.

Actually, if you don't want to waste a couple of butt splices, here's an even easier/better test.

Pull one strand out of a piece of wire, making sure there's no nicks in it (this will skew the results). Tin one end with solder. Now, holding the tinned bit in one hand, see how many times the wire will bend at the tinned/untinned joint.

Then see how many times it takes for the other end...

'78E original owner