Question on Crimping Terminals.

[George7941]

This is from page 48 of the current DelCity catalogue (could not find it on their site) and it has puzzled me for the longest time. Their crimping instructions for non-insulated terminals (whether butted or brazed seam) shows the indent opposite the seam. I always put the indent on the seam since it seems to me there is a less of a tendency for the seam to open up when the indent is not opposite the seam.

Where am I going wrong, if I am?

 

[Kiwi_ME]

But it seems clear the seam-side *will* open up if you don't contain it in a concave die when you compress the fitting.

 

[cornfused]

Are you using the correct type of tool?
Some are made specifically for insulated or non insulated terminals.

Usually I like to use the ones with the shrink tube on the end cause that glue really helps hold the wire in well.

 

[Chris142]

I've always done it the way that they show to be correct. I'll solder it too if I can.

 

[George7941]

Originally Posted By: Kiwi_ME
But it seems clear the seam-side *will* open up if you don't contain it in a concave die when you compress the fitting.


Sure, but assuming that the correct die is being used, my concern is more with long term use, the way they have it the seam could open up later and relax the crimp force on the copper wire.

Quote:
Are you using the correct type of tool?
Some are made specifically for insulated or non insulated terminals.


Yep, I have separate crimpers with the dies for insulated as well as non-insulated terminals.

Quote:
I've always done it the way that they show to be correct. I'll solder it too if I can.


I solder for weatherproofing. Soldering will seal up one end of the crimp and the other end gets sealed up with heatshrink.

 

[Kiwi_ME]

I don't really see what event would cause the seam to just open up one day - it's very strong mechanically and may even age harden somewhat. As regards the soldering, I've done the same but really don't think it's a good idea for numerous reasons, including that the heat may relax some of the crimp tension.
A better idea IMO would be to saturate the strands in silicone dielectric grease before crimping.

 

[George7941]

Ok, let us consider what happens when the crimping tool relaxes compression force on the joint. The relaxation force is acting outward against the wall of the terminal and, with the recommended way, the force is at right angles to the wall of the terminal at the seam where it is the most vulnerable (butted seam). A force at right angle to the wall has the most leverage and is thus most likely to open up the wall.

 

[Torino]

No matter how careful one is on the crimping procedure a stress condition is formed. This stress results in failure. Solder the joint and provide some support to avoid (as much as possible) flexing at the solder and wire juncture. I REALLY don't like doing the job twice. John--Las Vegas.

 

[Kiwi_ME]

In my DIY (and engineering) experience the style of crimped connector under discussion is not nearly as reliable as the type you will find on a production vehicle at every electrical connection outside of a PCB. And you won't ever see those soldered for numerous reasons.
But, on the other hand those crimps are of the type that presses the "ends" into the wire (like a "B" shape) without leaving a gap.
I think it's just a matter of different crimping technologies and production engineers will have great incentive to get it right.

 

[severach]

I always solder to make the connection weather proof and vibration resistant. A hand crimp doesn't apply enough pressure to swage the connection.

Weatherproofing the connections solved the need for solder. Before that aging equipment would work poorly simply because the exposed connections had corroded.

 

[Dualie]

I just started using Crimp, solder and seal connectors on anything i give a rats [censored] about. SO far so good

 

[doitmyself]

For those who "think" their method is correct, be it crimping, soldering, or combined, you should google the subject and execise your OCD. Aviation, boating, and car enthusiasts argue the crimp vs. solder methodology ad-nauseum.

If memory serves, soldered connections are forbidden in aviation and the boat building industry "standard" also recommends the use of crimps only. Someone correct me if I am wrong. These are two harsh environments that "favor" crimps only.

Here is an excerpt from one site: http://www.virginiawind.com/tips/060801_02.asp

"Most crimp terminals are designed to be crimped, not soldered. If the crimp was done poorly, solder won't save it. And if the crimp was done properly, solder is unnecessary. In fact, soldering a crimped terminal may weaken the mechanical connection, may reduce electrical conductivity, and may damage the terminal. As a general rule, you should not solder a crimp terminal."

"In the final analysis, a soldered connection is neither inherently better nor inherently worse than a solderless connection. Each has its advantages and disadvantages, and each may be appropriate or inappropriate for a given application. The key to a successful electrical connection is to remember that, if you choose to solder, you must be able to solder properly, and if you choose to crimp, you must use the proper tool and select a solderless terminal that is suited both for crimping and for its intended use."

I"ll let you guys study why poorly soldered connections can be as bad as a mediocre made crimp. It's a fascinating debate, IMO. Nearly all of my crimping is on indoor building work that is less demanding.

Cheers.

 

[tom slick]

The majority of connections I've seen on military cargo aircraft were crimped but they did use some splices with solder built into the shrink wrap.

These are the best crimps I've seen (molex style) they are OEM on many wiring harnesses.
http://www.molex.com/tnotes/crimp.html

 

[severach]

That was a pretty lame article.

Weather is the problem and there are different ways to solve it. While tracking down a voltage rise on a GM one wire sensor I pulled apart the wiring harness because I thought that one of the in harness crimped common grounds might have corroded. Though 15 years old the 8 wire crimp was still flawless. I soldered it anyways since I had disturbed the tape seal. No change in the voltage drop which was elsewhere--out in a weathered connection.

Here GM sealed the wiring harness. I sealed the connection with solder. Other connections are sealed with silicone, weather proof connectors, or swaging. So long as the connection is sealed it doesn't matter what crimp or solder standard is followed. If a connection is not sealed then some sealing method must be chosen or the connection will not last.

I've worked on 15 year old boats where not much still works because of corroded crimped connections. If the connections had been soldered they would have still worked perfectly. Weatherproof would be fine too. Pick something because crimped connections out in the open will fail sooner than a crimped connection sealed by the worst available method.

First step is to fire the morons that don't look at aging equipment to find their mistakes. The second step is to ignore engineers who's primary job is non obvious planned obsolescence.

The debate is one sided for me. My soldered connections never fail.

 

[Kiwi_ME]

Have any of the proponents of soldering for "weather-proofing" considered that the "connection" end of the lug has exactly the same problem as the "wire" end? Both ends rely on the elastic properties of metals to make an electrical connection.

Take apart any multi-pin electronic sensor connector in a modern vehicle that resides outside the passenger compartment. Note that for each conductor the inside is a pair of mating lugs pretty much like we are discussing here, although usually with a "B" type crimp. Note that the entire connection from one end to the other is sealed against moisture ingress, not just the wire terminations. Note also, you will never see them soldered.

 

[George7941]

Originally Posted By: Kiwi_ME
Have any of the proponents of soldering for "weather-proofing" considered that the "connection" end of the lug has exactly the same problem as the "wire" end? Both ends rely on the elastic properties of metals to make an electrical connection.

Take apart any multi-pin electronic sensor connector in a modern vehicle that resides outside the passenger compartment. Note that for each conductor the inside is a pair of mating lugs pretty much like we are discussing here, although usually with a "B" type crimp. Note that the entire connection from one end to the other is sealed against moisture ingress, not just the wire terminations. Note also, you will never see them soldered.


I solder for weatherproofing but under different circumstances than when you have mating connectore sealed at both ends.

Consider a ring terminal used for grounding an accessory you have just installed underneath the vehicle where it will live in a very harsh environmwent. If crimped, moisture will still wick into the wire strands and will invariably lead to a "green" death at the terminal. Soldering and heat-shrink will prevent moisture wicking.

 

[Steve S]

I crimp on the non seam side . Take off the plastic and do some crimps and look at them.

 

[brianl703]

One small problem with solder joints is that they can break due to vibration. I've seen it happen more than a few times.

As far as waterproofing goes, silicone dielectric grease or Nyogel 760G (available as Ford Terminal Grease) or some other type of grease designed for the purpose works fine.

 

[Steve S]

Originally Posted By: tom slick
The majority of connections I've seen on military cargo aircraft were crimped but they did use some splices with solder built into the shrink wrap.

These are the best crimps I've seen (molex style) they are OEM on many wiring harnesses.
http://www.molex.com/tnotes/crimp.html
THANKYOU!!!

 

[severach]

Originally Posted By: brianl703
One small problem with solder joints is that they can break due to vibration. I've seen it happen more than a few times.

Solder only connections can break from vibration. Crimp them first then they won't. The crimp provides the structure and the solder makes it solid. The worst problem for soldering crimped connections is that the solder wicks out along the wire which extends the leverage of the stiff part. This puts the wire at greater risk.

There's always silver solder for high stress joints.