solder vs crimp

[Shadow Catcher]

The great debate solder versus crimp connections!
I'm a great fan of soldering connections and yet I hear the debate and the arguments that if you're using connections in a vehicle when you want to crimp the connections because they're less likely to fail because of vibration. One of the things that drove this questioning was that I remember 35 years ago that NASA went with a heat shrinkable solder connector in the wiring for the space shuttle. This had a central portion that had what I'm presuming is probably a silver solder with an outer heat shrinkable tubing with a sealant/glue. This was applied using a heat gun and they were very expensive.
I have been making solder connections and using heat shrink tubing around it to reinforce and seal out moisture for years, but this is primarily in a static environment.
According to the NIST national Institute of technology there is less resistance in a soldered connection, a plus when you're dealing with DC .I know how to make a good solder joint and my question is has anyone ever had a failure as a result of a soldered connection?

[emiller]

The only time I have seen one fail is one one of my mechanics solder a DC air compressor connection on a fuel truck here and it just carried two many amps so one it heated up the solder melted enough to pull out from the vibration. I try to solder most connections. we also go through a lot of heat shrink here. Most of our wiring is in explosion proof conduit. On my trailer not too much soldering just crimping and it works fine. I guess it would depend on your climate if you have a problem with corrosion.
Eddie

[jss06]

I soldered most of the electrical connections with heat shrink tubing on my old CJ-5 when I built it for rock crawling. I never had a soldered connection fail. Ever. I had multiple instances of crimped wires pulling out of the connections.

This was in a high abuse environment with lots of stess on the wiring harnesses as the Jeep gets bounced all over creation. I even started soldering my crimped terminal connections to keep them from pulling out.

I will solder all the wiring in my trailer so I don't have to worry about it.

BTW, you can get the heatshrink solder connections if you want them. they have them at Fry's electronics. I am sure someone in your area could get them for you. All you need is a small butane torch (creme brulee torch) to heat them up and melt the solder.

[MikeW]

I have been using the solder/heat shrink method for many years on RV, auto, marine and other applications. I can't recal ever having had a soldered joint fail due to vibration. I have, however, seen crimped connections fail due to corrosion.

Crimped is standard in aviation though, done correctly (takes the proper tools) a crimped connection can be as good as any other.


Your mileage may vary

[asianflava]

Crimps are perfectly fine, I think they get a bad rep because so many people use crappy crimpers and don't use the correct mandrel for the size of wire they are crimping. I'm also not saying that soldering is an inferior method. It's just a little labor intensive on a busy day at the stereo shop.

I installed the stereo system and alarm/keyless entry in my old truck shortly after I go it. I crimped all the connections. Alarms have lots of connections if you've never put one in. I had that truck had for 13years and 205K before I traded it in. I never had any problems with the connections.

I do use separate dikes, strippers, and crimpers. The crimpers are Mil-Spec ratcheting crimpers that I inherited.

[urban5]

As a Master Electrician, I ALWAYS solder my connections on automotive, or trailer applications. Crimping puts two different forces on a connection. One the squeezing force, and the other only comes into play when the vehicle is moving. It is frequency vibration. A good example to use so that you can see how two different connections fair in different circumstances is by using a toothpick. Take a toothpick between your index finger and thumb in one hand, and do the same with the other hand, then bend it back and forth ( toothpicks are brittle, but it will flex). Then use a pair of pliers to squeeze one side, and put the other side between your index and thumb, then try to flex again. You will find the toothpick breaks at the squeeze point. It is not scientific but it gives you the gist of what I am fixing to explain.

All Electricity has harmonics, and/or frequency. In a lab, with perfect circumstances DC does not, because its sine wave is stable and straight. AC flexs between pos and neg creating its frequency. In real life the same holds true for Ac, but DC has a slight change. DC gets noise, induced on it because in modern cars the alternator actually produces AC, which is converted by Diodes into DC. This is what creates the most induced noise on a dc wire. This noise combined with road vibrations, and mechanical vibrations, can make (and does in most cases) the wire break at the squeeze point of the crimp connector. Also failure can come from these same vibrations combined with the grip of the crimp on connection, to make a wire back out of the connector. How do you stop the back out? Squeeze it harder. What does that do? break down the wire.

When you solder the connection you essentially make the two wires, one, electrically speaking. Because the resistance of the connection while there, is so small it doesn't matter. Why? Osmosis. Osmosis (speaking as to electrical theory) means that the electricity travels along the out side skin of the conductor. Your wire should be stranded (solid will fail, and should never be used in autos,campers,trailers,boats, etc.) so it has more surface area to travel on stranded. A crimp on grips only the outside of the outside conductors, where as a solder not only does the same, but it also works its way around all the conductors, and grips them all. This not only makes the best electrical connection, but it also makes the best mechanical connection.

Hopefully this clears it up for you (if I did not go on a rant, or get off on a tangent). If the object moves solder its wires, mechanical will fail.

P.S. the heat shrink tubing with glue can be found at your local electrical supply store, as underground rated shrink tube. It isn't cheap, but you are paying for pure awesomeness as a waterproof covering for a solder joint. Install it with a heat gun only, start in the middle of the tube, work your way around and out. This makes the center shrink and excess glue works its way to the outside, when the hole thing is shrunk down there will be excess glue come out of the ends to seal the tube even better. Be careful cause it will burn the sin out of you. Course if you sin a lot.....

[urban5]

I just read Asianflava's post and would like to make a couple of comments. He seems to be a stereo installer (sorry if I got that wrong) which means he makes these connections for a living. He probably knows the "feel" of a crimp on being crimped to spec, but most people do not.

Also he uses a mil-spec racheting crimper. Not everyone has one of these in their tool box. I personally have never seen a racheting crimper for connections ranging from 16-12 AWG (not saying they don't exist, because I am sure they do. Just pointing out they would be hard to find). These would put the correct crush on a crimp on connector.

Lastly to say that a connection you make never fails would be a mistake. I have even had connections I have done fail. Of course my work carries a two year warranty, so I would see if it did. Is it rare? Yes, but it has happened I am man enough to admit it (meaning nothing against Asianflava, just meaning sometimes its hard for us professionals to admit).

Have I seen soldered connection fail? Yes, but it was a connection to a 3 phase motor that was on a CNC machine, that ran 24/7. With enough stress anything can fail. Your just change the odds, when you choose your connection method.

Exclaimer: I do not mean this post to cause any offense to anyone, just relating from experience.

[jss06]

Lastly to say that a connection you make never fails would be a mistake. I have even had connections I have done fail. Of course my work carries a two year warranty, so I would see if it did. Is it rare? Yes, but it has happened I am man enough to admit it (meaning nothing against Asianflava, just meaning sometimes its hard for us professionals to admit).

Have I seen soldered connection fail? Yes, but it was a connection to a 3 phase motor that was on a CNC machine, that ran 24/7. With enough stress anything can fail. Your just change the odds, when you choose your connection method.

Exclaimer: I do not mean this post to cause any offense to anyone, just relating from experience.

No offense taken. I was simply stating I have never had a soldered connection I had made on my jeep fail. But I was an eletronics tech major in college and have a lot of experiense working with solder, circuit boards and wire. Dont ask me about connections I made while I was learning.

[MikeW]

All Electricity has harmonics, and/or frequency. In a lab, with perfect circumstances DC does not, because its sine wave is stable and straight. AC flexs between pos and neg creating its frequency. In real life the same holds true for Ac, but DC has a slight change. DC gets noise, induced on it because in modern cars the alternator actually produces AC, which is converted by Diodes into DC. This is what creates the most induced noise on a dc wire. This noise combined with road vibrations, and mechanical vibrations, can make (and does in most cases) the wire break at the squeeze point of the crimp connector. Also failure can come from these same vibrations combined with the grip of the crimp on connection, to make a wire back out of the connector. How do you stop the back out? Squeeze it harder. What does that do? break down the wire.

When you solder the connection you essentially make the two wires, one, electrically speaking. Because the resistance of the connection while there, is so small it doesn't matter. Why? Osmosis. Osmosis (speaking as to electrical theory) means that the electricity travels along the out side skin of the conductor. Your wire should be stranded (solid will fail, and should never be used in autos,campers,trailers,boats, etc.) so it has more surface area to travel on stranded. A crimp on grips only the outside of the outside conductors, where as a solder not only does the same, but it also works its way around all the conductors, and grips them all. This not only makes the best electrical connection, but it also makes the best mechanical connection.

Great explanation! I will say that the connections I make at work (mostly low voltage DC) are crimp connections (actually are mostly crimped ferrules in terminal blocks) but are in a very low vibration enviroment (digital printing presses). The ferrules are crimped with ratcheting barrel crimpers.

[jimqpublic]

When I wired my towcar, I wanted the best. I never want a high-resistance connection which is what often happens over time with plain crimps.

My method was to start with tinned marine cable. Then I crimped, soldered, and protected with adhesive-lined heat-shrink tubing. The heat-shrink prevents any flexing from vibration, and it makes a waterproof seal which should prevent corrosion. Wires protected by plastic loom and zip-tied in place. Grommets when passing through metal.

By the way, to keep my pants up I use belt, suspenders, plus an elastic waistband.

[Larwyn]

I understand how a bad mechanical connection can induce noise in a circuit, but do not see how electrical noise in a low voltage, relatively low current DC circuit can cause a crimped connection to fail mechanically. If there is arcing or movement at the connection it was not properly crimped.

I still feel that an amateur or inexperienced "wireman" stands a better chance of getting a mechanically sound, low resistance connection using quality crimp on connectors with the crimping tool (preferably a ratcheting version) recommended by the manufacturer of the connectors than with solder.

The person who has developed the skill to make a good solder joint probably already has his own opinion of which method is best. I was trained by the Air Force back in '68 to solder everything, then worked in protection and control of power generation and transmission/distribution for the last 25 years where soldered connections only see very limited application while there are many thousands of crimped connections in every control house.

I can make the connections properly either way and feel that a properly soldered connection is superior to a properly crimped connection. However, I know that a properly crimped connection will survive the stress put on it in automotive applications, is much quicker than solder, and requires less training and skill. I crimp 'em myself, only occasionally solder anything. The only real advantage of solder in this case is that a good soldering gun is less expensive than a good ratchet crimping tool.

[Larwyn]

By the way, to keep my pants up I use belt, suspenders, plus an elastic waistband.

What no glue and staples????

[Cliffmeister2000]

I was trained by the Air Force back in '68 to solder everything, then worked in protection and control of power generation and transmission/distribution for the last 25 years where soldered connections only see very limited application while there are many thousands of crimped connections in every control house.
.

I was trained in the Air Force also, in 1975. Trained to solder and to crimp. Later, working at Beech Aircraft in Wichita, KS, I went to NASA soldering school for a week.

All that said, sometimes I solder, and sometimes I crimp. I've seen how aftermarket trailer hitch installers attach the cabling for the trailer electrical, and I'm pretty sure whatever you do will be better than that.

[Larwyn]

I was trained by the Air Force back in '68 to solder everything, then worked in protection and control of power generation and transmission/distribution for the last 25 years where soldered connections only see very limited application while there are many thousands of crimped connections in every control house.
.

I was trained in the Air Force also, in 1975. Trained to solder and to crimp. Later, working at Beech Aircraft in Wichita, KS, I went to NASA soldering school for a week.

All that said, sometimes I solder, and sometimes I crimp. I've seen how aftermarket trailer hitch installers attach the cabling for the trailer electrical, and I'm pretty sure whatever you do will be better than that.

The most time consuming and painful part of wiring, to me, when I was in the Air Force was bundling the harness with lacing twine. By the time you finished lacing up the cables in the back of a piece of equipment your fingers were all raw and covered with all the adhesive tape out of the first aid kit. These days it's just a bunch of plastic wire ties tightened and sniped with a ty-wrap gun and your done. The new way does not look as good till the door is closed, then they look just the same................

I agree that just about anything is better than the squeeze on connectors used by most hitch installers, but even they seem to work out just fine most of the time. I keep some in the tool box on the truck for emergency, get it home type of repairs. Have seen them covered with "mud, blood, and beer" and still working.........................

[Cliffmeister2000]

The most time consuming and painful part of wiring, to me, when I was in the Air Force was bundling the harness with lacing twine. By the time you finished lacing up the cables in the back of a piece of equipment your fingers were all raw and covered with all the adhesive tape out of the first aid kit. These days it's just a bunch of plastic wire ties tightened and sniped with a ty-wrap gun and your done. The new way does not look as good till the door is closed, then they look just the same................
[/quote]

We used "waxie tie cord" at Beech. I wonder if that was the same stuff you used in the Air Force? I was pretty good at it, too! I still remember how to do it. That stuff lasts forever! Zip ties deteriorate with age, sometimes as little as a year!