Crimp or solder electrical connections

[SED]

Being a belt and suspenders type guy I solder all connections and cover them with shrink tube, but an electrical engineer friend insists that crimping is better because it does not form a stress riser under the insulation which will lead to breakage.

I've experienced this type of failure once, but I've experienced many failed home crimps (not factory) that suffer similar vibration breakage, or more commonly corrosion and resistance. 

What will give the best long-term service home solder job or home crimp?

I'm adding a system fuse to a LMIII and want to do it right.
Thanks,
Shawn 

[ibis1]

Either method is acceptable if done correctly. If you crimp be sure and use the correct size connector and pack the connector with dielectric grease and use shrink tubing to further seal the connection. Quality parts and tools also go a long way to ensure a good repair. Good luck. 

[HardAspie]

I was always told to make the connection mechanically secure first, like twisting wires together, then solder it.

[Antietam Classic Cycle]

I've always been told to solder where there's no vibration and crimp where there is. <shrug>

[wymple]

I crimp, then solder whenever possible, followed with shrink wrap. My son pulls the insulation back, crimps, solders, and pushes the insulation back up.

[HardAspie]

That sounds good too!

[pyoungbl]

When I built my boat I did a bunch of research into this issue.  Salt water is mighty tough on electrical connections so doing it right the first time is important.  The crimp solution was the one recommended.  Why?  Well, solder creates a rigid joint that won't flex with vibration; each solder joint is only as good as the technique used and it's all too easy to get a cold solder joint; solder joints don't react well with our salty air. 

Bikes have even more vibration than boats, thus I think the answer is the same, better to have a good crimp on a connector that incorporates a high quality shrink wrap.  I use crimps (up to about 10 gauge wire) on my bikes and have no problems.  My supplies come from DelCity  www.delcity.net

Peter Y.

[SED]

Thanks guys!   WG has all the experts!    

Normally I try to do both without letting the solder wick up the wire away from the connector.  This time I used crimp and shrink tube on tinned wire ends because I couldn't get the 10 AWG connector hot enough for a good solder job.  Unfortunately I didn't think to use dielectric grease before crimping...  Oh well, easy fix.

BTW Peter, the friend recommending crimp only specializes in designing electrical equipment for yachts. 
https://www.bluesea.com/

[Triple Jim]

Normally I try to do both without letting the solder wick up the wire away from the connector.

That's what I settled on after many years of installing connectors professionally.  It's like an oil thread, there are many correct answers.  Choose the one that has the lowest failure rate for you.

[MGPilot]

I've always been told to solder where there's no vibration and crimp where there is. <shrug>

This ^

In aviation where vibration is a significant issue, crimping is the only accepted technique.

[Arizona Wayne]

I crimp or solder but not @ the same time.    Used do to appliance repair and use a Vaco #1900 crimper made for 10-22 gauge wire.  It has never let me down. It punctures the terminal into the wire.   

[canuguzzi]

When I built my boat I did a bunch of research into this issue.  Salt water is mighty tough on electrical connections so doing it right the first time is important.  The crimp solution was the one recommended.  Why?  Well, solder creates a rigid joint that won't flex with vibration; each solder joint is only as good as the technique used and it's all too easy to get a cold solder joint; solder joints don't react well with our salty air. 

Bikes have even more vibration than boats, thus I think the answer is the same, better to have a good crimp on a connector that incorporates a high quality shrink wrap.  I use crimps (up to about 10 gauge wire) on my bikes and have not problems.  My supplies come from DelCity  www.delcity.net

Peter Y.

 :1:

A proper crimp will not come lose. The idea that soldering a crimp makes it stronger isn't the total picture because strength does not equal durability.

Anyone notice that cables leading from your batteries are not soldered? Someone knows something.

[mach1mustang351]

I had a friend that worked for a place that made power supplies for military applications. When we did large electrical projects we would crimp the connections with an uninsulated butt connector, clean with alcohol, then solder the joint, and seal with shrink tube.  Usually in my real life where I want the best for the effort I get the shrink tube type connectors and crimp with a high quality tool and seal.

[dilligaf]

Good crimping tools are not cheap. If you do not have the proper tool, solder. 
Matt

[mtiberio]

NASA crimps... Just saying. You think they take the time to solder the bazillion connections in the old Shuttle?

That said, a proper solder with minimal wicking into the stranded wire and heat shrink for strain relief will not fatigue off... I did that on my old race bikes and never had a failure.

[blackcat]

Good crimping tools are not cheap. If you do not have the proper tool, solder. 
Matt

$335 bucks for this tool. I guess my crappy $18 dollar tool is not equal?



How about this compromise at $45 bucks?

[rodekyll]

The top one is what I use for network cable.

The bottom one -- eeeew.  Just eeeewww.

[Chuck in Indiana]

This ^

In aviation where vibration is a significant issue, crimping is the only accepted technique.

+1

[Rich A]

I usually crimp then solder.

My problem with crimps is that they sometimes don't fit perfectly; maybe that's because I use different types of wires as they are sourced from different places (and some are integral to the components being connected). I've tried several different (up to $100) crimpers, and some work well in one application not so well in others. `

I've had crimped connectors pull apart, but never had an failures of crimped/soldered or soldered connections.

Rich A

[charlie b]

All of the above.

I use a lot of Molex connectors on the bike (and other vehicles).  My crimp tool was $30 (for one size molex).  It works like a champ and duplicates factory crimp.  Using the a good crimp tool is key.

I have also been known to solder connections in some places.  When I do I also 'reinforce' the wire with shrink tube, sometimes two layers of it.

[Antietam Classic Cycle]

If you use "double crimp" terminals and a proper crimping tool, I'm not sure how they'd pull apart, since the terminal is crimped onto both the wire and insulation.

[lrutt]

If you use "double crimp" terminals and a proper crimping tool, I'm not sure how they'd pull apart, since the terminal is crimped onto both the wire and insulation.

+1 this solution. These make for a superior connection. I just got done re-furbing a harness for a 65 Honda CT200 using Vintage Connections terminals.

[Moto]

Good soldering can be better than bad crimping, but good crimping is best where there is vibration!

A good crimper automatically rolls and drives the small tabs near the terminal into the wire, and at the same time gently wraps the longer tabs around the wire's insulation to form a strain relief. Because the plastic insulation winds up holding the wire inside the strain relief, vibration is damped and not transmitted directly to the solid terminal crimp. Different types of terminals require different crimping, so good crimpers provide exchangeable dies that are suited to different types.

A good crimper with replaceable/exchangeable dies costs $35. It is from http://www.vintageconnections.com/, and is found part way down their home page. It comes with dies that are suitable for the types of connectors used on Guzzis (Molex or Hitachi, depending on the era). Other styles of dies for it cost $12 each type. Here is their guarantee:

"Our crimping tool manufacturer sells their tools worldwide, under a broad range of OEM brand names, such as GC Waldom, and Tool Aid, among many others. The tool model pictured above is the only model of ergonomic crimping tool from that manufacturer that offers a patented 30% reduced-compressive-force design, for ease of prolonged use. We're in our second year of retailing it [that is, their 3rd-generation version]. Are there better tools out there? Sure... if you don't mind spending from 200% as much, to as much as 1000% more money to buy FAA-certified crimping tools that are intended for airframe repairs. We're so sure our tool will make you smile,  that we promise you this: If you try our crimping tool and learn the crimping technique, and it doesn't duplicate the quality of the crimps in your original factory harness, send it back and we'll refund your original purchase price. Guaranteed. In our 11 years in business, and with thousands of crimping tools sold, only one crimping tool has ever been returned to us for a refund. Only one!"

I recommend it for use on terminals. For direct wire-to-wire connections away from the terminals I prefer to twist, solder and shrink-wrap. My electrical installations on bikes have been very reliable since I adopted these practices.

Moto

[canuguzzi]

If your crimps aren't holding, you're doing it incorrectly or using the wrong crimps or tools. Soldering can break down if subjected to vibration and/or twisting and movement.

If you are using stranded wire which is designed to flex why on earth would you solder it to defeat the very design the engineers put into the wire? Do you know more about it than they do?

[Mark West]

A proper crimp will make a better connection than solder every time. you do need the right crimp for the wire you have and the proper tool to crimp it. If the crimp has a strain relief, I see no reason to add solder. And for gods sake don't put any grease on the wire.

[Farmer Dan]

If you use "double crimp" terminals and a proper crimping tool, I'm not sure how they'd pull apart, since the terminal is crimped onto both the wire and insulation.

This type of connector is just about perfect.  I like to use molex connectors too.  Just make sure you use the right crimping tool and a good quality one.

[Jurgen]

A proper crimp will make a "gas tight" connection.  Adding solder won't make a difference since the solder can't flow into the crimp, it will only make the un-crimped wires rigid and fail under vibration.  On an aircraft different size wire cables save weight, therefor different size connectors are required requiring different dedicated crimpers (expensive).  With MC's we can get away with fewer sizes of wire and probably one good crimper.  Check the Waytek website for good crimpers and quality terminals at  www.waytekwire.com and yes, you can add grease to a terminal for waterproofing, but NOT before crimping.  J�rgen

[ITSec]

I crimp most of the time, solder on rare occasions. However, I almost always use the crimp connectors with heat shrink and seal type wraps. These keep the moisture out of the new connection point, and provide a full insulation-to-insulation cover over the crimp point. Posi connectors are another good solution, but are not easily available and may not have the design required for every application.

Where I know I will need to have a disconnection point, I use Molex connectors with the appropriate number of posts/receivers. If it's possible, I will use a shrink-wrap sleeve to the back (wire) side of the Molex connector's nylon shield.

[rodekyll]

All good advice.

I worked for a guy who told me  "solder is to fix your gawd-awful bad crimps."  So I learned how to crimp.  I've done a couple hundred or more on the trike harness so far and a guy'd be hard pressed to tell them from a factory job. 

When in doubt, look at what the oem did and how they did it in similar contexts. 

[wymple]

I don't solder to keep it from coming apart, I do it for conductivity. I only solder the tip of the wire, and crimp behind that for strength. And I crimp 1st, solder second. I do not have wires breaking off.