Crimp Connections

[CleviteKid]

Are they any good? What if I solder the wire strands first, then crimp? Some of my colleagues have investigated crimp connections in a home appliance, and the results are at
CRIMP (http://cs.pennnet.com/Articles/Article_Display.cfm?Section=Articles&S&Subsection=Display&ARTICLE_ID=214068)

You may need to fill out a free registration to see this, I did not.

Dr. Lee :cool:

[CareyWeber]

Originally posted by CleviteKid:
Are they any good? What if I solder the wire strands first, then crimp? Some of my colleagues have investigated crimp connections in a home appliance, and the results are at
CRIMP (http://cs.pennnet.com/Articles/Article_Display.cfm?Section=Articles&S&Subsection=Display&ARTICLE_ID=214068)

You may need to fill out a free registration to see this, I did not.

Dr. Lee :cool: Dr Lee,

I crimp then solder and cover with heat shrink.

Carey

[MTTwister]

DR Lee - I like Careys' approach - I've found it's real difficult to get a good crimp on a pre-soldered strand. Also - by the time I've laid into a pre-insulated connector to get a good crimp - I've practically eliminated the value of the insulation. :rolleyes:
Now I wonder how many bum crimps I have.. I will be real careful on the 120v stuff in the future, for sure.

[moondoggie]

Good Day!

A properly-crimped connection is as good as soldering.

At a local vendor, I found crimp connectors that heat shrink. In other words, you crimp the connection, then heat shrink it. The heat shrink contains an adhesive that oozes out both ends of the crimp connector. After heat shrinking, the connector is completely sealed, so no corrosion can occur. These also used to be available from Marlin P. Jones, an overstock electronics supplier.

I've personally had no luck soldering connections on vehicles. They always broke off at whatever point the solder crept up inside the insulation, after a few months or years service. I've NEVER had one of these crimp connectors give trouble.

Blessings!

Brian Johnson, #5044

[CareyWeber]

Originally posted by moondoggie:
Good Day!

A properly-crimped connection is as good as soldering.

At a local vendor, I found crimp connectors that heat shrink. In other words, you crimp the connection, then heat shrink it. The heat shrink contains an adhesive that oozes out both ends of the crimp connector. After heat shrinking, the connector is completely sealed, so no corrosion can occur. These also used to be available from Marlin P. Jones, an overstock electronics supplier.

I've personally had no luck soldering connections on vehicles. They always broke off at whatever point the solder crept up inside the insulation, after a few months or years service. I've NEVER had one of these crimp connectors give trouble.

Blessings!

Brian Johnson, #5044 Brian,

Broken soldered connections are a sign that you used to much solder and it flowed down the wire under the insulation making the wire stiff and then it cracks where it tries to flex.

I have soldered connections on my truck that have lasted well over 120K miles. When I worked as a mechanic at a trucking Company we soldered all connection period and we were required to remove cimped on connectors.

Carey

[moondoggie]

Good Day!

All of that being true, it doesn't change the fact that a properly-installed crimp connector is as good as soldering.

My experience with soldering connections on vehicles is limited. I found that it didn't matter how far up inside the insulation the solder may have travelled, or whether it went up the insulation at all. Wherever the solder ends, the connection transitions from solid to flexible, & it always broke there.

An example would be installing a replacement lift pump without the proper connector on it. If I soldered it in, the solder ends somewhere. The wires are twisted together, soldered, then heat shrink tubing installed over the wire prior to soldering is moved into place over the splice & shrunk. I even tried multiple layers of heat shrink, with the 1st layer longer than the subsequent layers, to move the stress over a longer portion of the wire. Still no joy.

I suspect this is just another one of those things I'll never get the hang of. :( The good news is, the heat-shrinkable sealed butt splices I discussed previously work great for me.

Please take in the spirit given, which is, at least for me, ALWAYS the desire to learn more from you folks, who generally have experienced things I haven't & probably know more about such things than I do. :D Thanks for your feedback.

Blessings!

Brian Johnson, #5044

[JeepSJ]

Having wired many vehicles, both using aftermarket kits (Centech/Painless) and totally hand built custom setups on everything from a stock early Bronco restoration to Formula Ford vintage racers to unlimited class desert trucks, I have to say that nothing beats a properly soldered joint. If I have something happen in the field and I need a quick fix, I use a crimp style, then cut it apart and solder and cover with shrink tubing when I get back home. I use soldered joints wherever I can. In the spaces where I can't solder, I use a non-insulated connector and cover it with shrink tubing.

This is not to say that you can't get a good joint with crimping, because you can. Uninsulated crimp better than insulated, probably for no other reason than you can get the connector properly inserted into the tool. And, that it not to say that you can't get a good crimp on an insulated connector, because you can.

If you are going to crimp, then spend a few extra $$ and buy a quality crimping tool. The crimpers that have two flat surfaces (usually included in the el-cheapo kits at your local auto parts store) are worthless, except in an emergency. The best crimper will have both jaws curved like this )). Also important is the location of the seam in relation to the crimp. Always crimp like this )0-), where the )) are the jaws of the crimper, the 0 is the terminal, and the - designates the location of the seam.

There is a correct and incorrect way of soldering as well. You do NOT want to twist the wires. You want as much contact between the strands as possible. It is better to fan out the strands so that it looks like the end of a piece of rope, then butt the wires together so the strands are all intertwined, then roll it between your fingers to smooth the joint, then solder it.

When we get moved into our house at the beginning of December (and out of this !@#$% condo) and I get my garage unpacked, I'll take some pics and post them. I have to build a glow plug circuit anyway... I'll try to get something posted before the end of the year.

Moondoggie - the crimp terminals with the built-in shrink tube are excellent. Moisture, oxidation, etc... are brutal on crimp joints. Those terminals are right up there with the uninsulated with shrink tubing. Everyone should be using those as a minimum.

[Peter J. Bierman]

At work we use all kinds off wireconectors from pre insulated to those sealed things and soldering.
All work fine on heavy equipment when the right tools are used, as stated by JeepSJ, and use the right size crimp!

Things you don't want to do are:

Use any kind off pliers for crimping just the right tool!
Use those blue thingys that cut through the insulation off both wires and then click tight.
Use any kind off solder fluid stuff couse it;s corrosive and will go inside the insulation and eat the wire core away.

If you stick to this you'll be fine ;)

Peter

[tom.mcinerney]

A GOOD crimp of a quality connector on clean wire is as good as solder. Cheap connectors poorly crimped are garbage. Good connections in an environment with vibration require insulation support and/or stress relief.
Never crimp AFTER solder.
If solder: Always use electronic solder (as 60/40), rosin-core for electric/electronic junctions. The rosin is mild flux, inactive at room temp, not very soluble.
Don't use acid core solder , or acid flux (HCl for steel , or the ZincChloride-containing soldering paste favored for plumbing sweat fittings) on electric/electronic joints.
[I once wired a boat with running lamps...all connections corroded thru in 2 weeks salt air/spray...i used paste flux to aid cleaning the wire strands, oblivious to the fact that i was seeding the joints with acid that the salt air would maintain an active corrosion cell!]

[moondoggie]

Good Day!

[sidedump]

Here is the sandard for proper connections set by Mobile Electronics Certification Program or MECP.
Terminating the end of a wire should be done as carefully as possible. Most connections today are done with a crimp tool which attaches the wire to a solderless crimp-on connector. Whenusing a crimp-tool, the seam of the metal berrel, unless it is seamless, should be in the concave part of the crimper's jaws. This makes for a secure mechanical connection. Fore connections in the engine bay of a vehicle, it's important to solder the connection and then heat shrink the connection and terminal withe a piece of shrink tubbing. The tubing must cover the bottom of the connector (where the wir enters to connector), as well as go all the way to the top of the connector. Cover as much of the copnnector as possible. (This is not possible with a ring connector.) When the connection is firmly attached to the firewall, it is good practice to apply noncorrosive grease to the screw headand the terminal.
The only drawback to crimping is that over a period of time, oxidation can build up between the wire and the connectors. This oxidation causes a degradation in the electrical connection. In othe words, it causes resistance which will hurt the overall performance of the unit involved.
Solder should be applied so that it flows over the connection. For best results, the iron should be held below the wire while applying the solder from above. This allows the solder to flow from the top of the wire to the bottom more uniformly. Remember to heat the connector, not the wire. Two or three "balls" of solder (a cold solder joint) is not good enough because they will contain air bubbles and either break off or have little to no electrical connection value. Merely slodering a connector, therefore, is not adequate. Soldering is an electrical connection only, not a mechanical connection, and will not have the long-term strength necessary to keep up the integrity of the connection.
There a text book answer..... :D

[JeepSJ]

"Never crimp after solder" is excellent advice. However, you can solder after crimping, and doing so will increase the quality of the electrical connection. Good point, sidedump.

[LanduytG]

Crimps are good but you need a quality crimp tool and connectors.

greg

[jspringator]

I use Ancor rachet crimper, and Ancor crimp connectors. Then seal them with shrink tube. West Marine sells them.

[Turbine Doc]

Quality of the crimp & using proper tool is so critical for a MIL spec quality connector we are required at work on our engine harnesses to use a tool that is calibrated & certified to make uniform crimps.

This is overboard for our needs but it does highlight sensitivity to quality of the crimp. In flight engines and jets we use on ships shock & vibes are real world obstacles to rekon with, crimps properly done allow for 20+ years of service, soldering isn't required.

Mil spec tools/connectors ain't cheap and usually out of real for most, for those things that I feel the need to be as fail resistant and affordable I can get I look to marine crimp connectors like you find a a boat supply store, better quality than the typical made in China kit at auto parts stores, plus socket is filled with dielectric grease/silicone working as a moisture barrier to longer resist corrosion problems.

[dcalex]

Yikes.....everybody has their story and they're sticking to it tongue.gif ...Me too.

If I want a connection that I want to be trouble free.....it gets soldered...period....I too like to crimp, solder, then shrink tube. The crimp holds my work...(generaly while I'm standing on my head and can hardly even move my elbows), the solder eliminates any corrosion problems, and the shrink tube gives it mechanical protection. The first thing I do with a new trailer when I get it is cut all the connections and solder them. I don't have troubles with trailer lites.
Some good advice has been said here re soldering. I'll add my own two-bits worth. The mantra for soldering is clean & hot. Clean is easy, but too often we get in a hurry and don't pay enough attention to it. Hot is easy too, but needs an explanation. The soldering iron or gun should be very hot. If not, you wind up holding it too long on the work and the wire (being a good heat conductor) conducts the heat way up the wire away from the joint. Solder flows toward heat....thus you wind up with a stiff piece of wire where it will flex and break. If your soldering say, an 18 gauge wire, you shouldn't have to hold the tip to the joint more than 3 -4 seconds. If you do....take the tips from the gun and clean where they clamp into the gun....they're corroded and it's not getting hot enough. The solder on the completed joint should be very bright...like a new dime...that indicates a good hot solder job. If it's dull, greyish looking...it's a cold joint and you need to re-heat it....after cleaning the tip contacts.
I haven't tried the new sealing crimp connectors yet, but I hope they're what they say they are.

[moondoggie]

Good Day!

Well said! As before, the only REAL reason I brought up the heat-sealing crimp connectors is so folks would know there's another option out there.

Please take in the spirit given :D , but no matter how you solder, there will always be a place where the soldered wire ends & the un-soldered wire begins, which means there will always be a place where the stiff soldered wire meets the flexible un-soldered wire. That's where all my solder joints broke. I probably didn't strain-relieve them with enough layers of heat shrink tubing, I don't know. I'm EXTREMELY pleased with the results I've obtained with these heat-sealing crimp connectors.

Blessings!

Brian Johnson, #5044

[tom.mcinerney]

On my dad's boat a tech used the heat-sealing crimp connectors on all ignition circuits about ten years ago. They're now as good as new. I'm impressed; although the crimp may not be first class, the combination of a good crimp, an airtight seal, and insulation support via the seal, makes these a worthy contender. I plan to start using them sometimes.

[gmctd]

For many years, now, I have crimped, soldered, coated the joint with Permatex Black RTV, then immediately heat-shrinking over that.

The RTV oozes out the ends as the tubing shrinks, providing oil\water-tite seal and additional flex strength.

Wipe the connective terminal with lacquer-thinner before the RTV cures.

Looks like factory splicing, 'cept theirs is beige.

[moondoggie]

Good Day!

Wow - that sounds like another great way to get a reliable solder connection.

Thanks & Blessings!

Brian Johnson #5044

[Stray Cat]

Wow! What a string...lot's of feedback; some good, some bad. I saw only one mention of MilSpec (Military Specifications) in the whole string. Unfortunately, I took five weeks of MilSpec soldering training! It seems that there is not enough about soldering to fill five weeks, but there is. I will address what MilSpec says about this particular question. If you are going to crimp a commection, which MilSpec generally doesn't agree with, you must first strip and tin the wire being crimped. The wire should be stripped to just longer than the connector that it will be crimped into without nicking the conductor or disturbing the manufacturer's twist on the wires of the conductor. "Tinning" the wire is coating it with solder. The tip of the iron should be hot enough to melt the solder quickly and flow it away from the tip and toward the insulation without melting or burning the insulation in the process. The solder flow should be stopped at a distance from the insulation equivalent to the thickness of the wire (i.e. for 14 gauge wire, a couple of millimeters). You should be able to see the original wires, with their original manufacturers twist, through the shiny solder; otherwise you have used too much solder. The tinned tip should be more rigid that the un-tinned wire, but still flexible enough to bend rather easily; otherwise you have used too much solder, or overheated the wire. Then the connector may be crimped to the wire usingthe proper crimping tool. According to MilSpec, you NEVER solder after a crimp connection has been made. The explanation for this is that the heat required to bring the connector up to a temperature that will flow the solder will damage the wire and insulation. That being said, if done carefully, I personally like the strip, tin, crimp, solder, and insulate method for termination connections. I like the strip, tin, solder, and insulate (no crimp) method for in-line connections. Although, I will use butt connectors for non-critical connections because of their ease. Don't even ask me what MilSpec says about soldering on multi-layer circuit boards!

[autocrosser]

If you want a good crinp connection you should use one of the ratcheting mil spec crimpers with jaws designed for that particular connector/wire size. They aren't cheap but they do the job. that's why you find them on sircraft and other critical equipment. Using a cheap hand crimper is asking for trouble on critical connections. Also solid wire doesn't do good on crimp connections. You don't get the deformed compression.

Soft materials like aluminum wire compresses after being crimped and sometimes starts to develop heat at the junction that multiplies with time. That's why is isn't used much anymore unless special connectors are used.