To Solder or Not.. That is the Question

[wingless]

Originally Posted by Ex-Calif

Nasa says avoid it

Here is the NASA specification defining their requirements on soldering properly.

[MarkSF]

I see an awful lot of airliners flying around, all with miles of wiring, and a high level of electrical reliability. So logically, it seems to me that they've hit on a technique to make connections reliably.

I'm assuming Boeing, Airbus, et al use crimps.

So they're good enough for me, too.

[travellerw]

Hhhmm this post has definitely been hot..

At this point, I don't see any reason to change my method since I know how to solder. I still believe its the most bullet proof method, even if it is "gilding the lilly".

I think what it boils down to.. Properly crimped connections are suitable, but if you have the skill, equipment and proper solder, then there is nothing wrong with soldering.

A couple of other items.. Lead free solder is required if you want your product to meet ROHS standards. There is nothing stopping a regular individual (even a repair shop) from buying and using leaded solder. Ebay is your friend (Kaina is a good brand).

As to Boeing, Airbus, ect... I have no idea what they use for connections. Would be interesting to hear from someone in that industry. A quick google search show military spec connectors being acceptable as both soldered or crimped.

[goboatingnow]

Originally Posted by Nicholson58

I use only marine grade pre-tinned wire. I use only silver solder and the appropriate non-acid flux. I use crimp connectors at all screw terminals. Sometimes, I solder the wires before crimping, especially small & very fine wires. I occasionally have to splice wires. For this, I use solder and then cover with heat shrink. Its messy, but I work 3M 5200 under the heat shrink before shrinking. This is waterproof. On very large crimps such as #4, 6, 8 and battery type 4-0 I first treat the wires with corrosion protection goop and then crimp. I have bought several so-called good crimpers & I am not confident in any of them.

What ya do if making up RJ 45 connections then ???

Dave

[d design]

Did someone say solder joints are weak? What a fking load of b*ll Shiyt! A piece of wire that is being pulled at each end until it breaks will not break at a proper solder connection but further down the wire. Problem is there is hardly any boatie DIYers that actually know how to solder. So yep get your Crimps out if you like but I'm soldering because it works for me...hah!

[model 10]

Aircraft use crimped connections, lots and lots.. I don't remember seeing very many solder joints. There are approved ways to make a solder joint but it takes forever and it's very old fashion. Of course on the inside of a component or a plug there are solder joints.
Shielded wires often have a solder joint to the shielding but it is part of the connector. It melts a bit of solder onto the shielding when you shrink it with a heat gun. They are usually used in radio systems where everything needs to be shielded.
The latest trend seems to be heat shrink insulation on the connector if it is in the wx or in an engine compartment. no extra heat shrink is needed. Crimp it, heat it and you are done.
I am sure glad all these other ideas I'm reading about in this post are not approved by the FAA. All the crashes would give air travel a bad name.

[Ex-Calif]

Originally Posted by wingless

Here is the NASA specification defining their requirements on soldering properly.

I didn't say NASA prohmibits it. They have specific criteria for when it can be used.

You posted the how to spec. A couple weeks ago in a different thread I posted the when to spec.

Did you read the spec you posted? I did not see anything about joining two wires...

[goboatingnow]

Originally Posted by d design

Did someone say solder joints are weak? What a fking load of b*ll Shiyt! A piece of wire that is being pulled at each end until it breaks will not break at a proper solder connection but further down the wire. Problem is there is hardly any boatie DIYers that actually know how to solder. So yep get your Crimps out if you like but I'm soldering because it works for me...hah!

Soldering a flexible strand wire, creates a hard point , furthermore it also creates a corrosion site. The loss of ductility and flexibility will cause premature failure in a situation where vibration is common. Many crimp terminals are not specifically tinned for soldering and it's common that a poor electrical connection is made, even if it " looks" right

Good crimp is best, that's the general industry practice for wiring looms. Of course worldwide amateur sparks know better !

Dave

[bletso]

I have been soldering for nigh on to 50 yrs., but we started crimping 25 yrs ago. Crimping is superior in many ways, but it takes, as pointed out, a good
crimping tool and lug. I manufacture industrial quality control equipment which operate in harsh environments. Before that I worked for another company who up until the 80's soldered everything. I ran into some very interesting and difficult problems with solder connection on occasion.

Yes it took a long time for me to be convinced of the merits of a good crimp connection. (Old school and all.) Also, as pointed out, soldering is an art and the new RHOS solders aren't worth crap, so it's even more important to get the proper tools and crimp. I can also assure you that many who say they can solder really can't, but with the right tools, almost anyone can crimp!

Remember as well the wire stripping. That is the source of most solder and crimp failure, i.e. nicked strands of wire. Take Maine Sail's advice. His article is well written.

[Maine Sail]

Originally Posted by wingless

This reply has good information and links on crimping and splices.

This reply shows how I implement staggered, soldered Western Union splices, using the wire to provide mechanical support.

Western Union / Linemans splices are, and have always been, intended for solid conductor wire. They are not intended to be used for stranded wire let alone the finely stranded wire we use on boats. NASA prohibits WU splices on stranded wire.

Originally Posted by wingless

All wiring should conform to ABYC specifications.

Seeing as you said that, in one of the links;

The ABYC does not consider a WU splice a "mechanical connection" thus a soldered WU splice is considered "solder as the only means" and does not meet *ABYC standards. Again the WU splice is intended for solid conductor wire. We don't use solid conductor wire on boats and in fact go to the far extreme and use very finely stranded wire..

*This came from an E-11 standards clarification question that was clarified by John Adey.

That said, on your own boat you can do as you wish, until of course you get a surveyor who actually knows his stuff for an insurance survey...

BTW I have not said don't solder. What I have said is crimp first then if you are competent and insist on soldering, feel free to. The keys are crimp first and that you are COMPETENT at soldering...... I still don't believe it is necessary, if proper crimping practices have been used, but if it makes you sleep better......

[Ex-Calif]

Originally Posted by wingless

Here is the NASA specification defining their requirements on soldering properly.

Sorry for the cross post...

As MaineSail said - it's basically your boat - no one is going to the moon so peace to anyone who wants to solder...

First of all I never join threads to convince anyone one way or another. It really is an uphill and frustrating battle. I will post why I do things the way I do and will challenge stuff that is posted that I believe to be urban legend or factually wrong.

My experience is people hold on to their paradigms tightly - including me - so I am always happy when someone presents factual evidence that shows I have a bad practice.

One can make a good or bad solder joint, one can make a good or bad crimp joint - Let's assume we make good joints. I then thought about why I believe what I believe.

I am always conscious of my long posts because nothing is simple and one liner posts never tell the story so, in honor of Dave Letterman here is Dan's top ten list for not soldering.

10 - I don't have a soldering iron at sea.
9 - tin is less conductive than copper - no need for tin
8 - solder does not seal the joint from water or other contaminants (see attached link) to a solder failure
7 - A bad solder joint is hard to detect without a SEM
6 - A solder joint by its nature is not stronger than a crimp joint
5 - Given the right tools for soldering and the right tools for crimping - crimping is easier
4 - A solder joint is not inherently more reliable than a crimp joint
3 - I believe that at the edge of the hard solder joint to the flexible wire a stress riser can exist that when placed under vibration can allow the wire to fail - i.e. wires don't "fail midpoint", solder joints don't "fail" in the blob- the wire fails "right next to" the solder joint - evidence of vibration induced HCF (high cycle fatigue) failure in the wire in my opinion. And the most likely vibration source in a boat is the engine.
2 - Not soldering is an ABYC standard

and the number one reason for no solder joints?

1 - I was trained and licensed as an A&P and was taught not to and passed a test that said it's not allowed under FAA regulations because of item 3.

I don't think many people know what a good crimp looks like - When done properly you can cut the joint apart and the copper and connector are close to one solid piece. They are literally fused under pressure. Most people think the crimp connector (bad word actually) is like clamping the wire to hold it in place. A better term would be "pressure fused connection" - BTW water doesn't get "inside" a good crimp. The weak point, same for solder joint, is the bare wire between the joint and the insulation of the wire - hence heat shrink need.

Here is a link to an outfit that has it about right -

Cable Crimping - Best Practices - BS7609 | ETS Cable Components

For a standard crimp you can basically dimensional test the crimp and know if you crimped too little too much or just right.

For an "authority" on the matter I hope you'd take NASAs word for it. They spent a lot of your tax money figuring this stuff out. If you want to be a "go to space" quality electrical harness assembler - you'd learn and apply everything in this document.

http://www.hq.nasa.gov/office/codeq/doctree/87394.pdf

Note in particular 13.3 - even NASA does allow for solder joints but pay close attention to what they say about supporting the wire and look again at my reason 3.

Here is a link to a lab that tested a failed solder joint - It is hard to detect a bad solder joint and all kinds of contaminants can get into a solder joint - in aviation some would be deadly.

Empfasis - Tin Whiskers: Risks with Lead Free Part I

If you made it this far - None of us are going to the moon and your trailer lights and your boat will be fine if you solder. I have soldered joints on boats and airplanes and I am not dead yet.

[Wotname]

I have been staying away from the crimp / solder debates recently - had too much to say about this subject in the past - suffice to say I crimp professionally, I solder professionally and I have calibrated various crimp tooling in the past. I don't intend to convince anyone of their entrenched positions.

But...

What makes some of you to think good crimps are gas tight?

It is just because you have read this from some manufacturers sales bumf or are you repeating some oft said mantra (maybe from the webbythingo) or because you have inspected / tested good crimps and found them to be so.

I believe some crimps (done in specialist labs) are probably gas tight but I have cut open several well made crimps made with calibrated tooling (and so forth). Once the ends were faced and polished and then viewed under high magnification, small voids were clearly visible between some conductors. They were clearly not gas tight.

This matches my experience of finding corroded terminals (both solder and crimp) in old marine wiring.

YMMV

[Dockhead]

Originally Posted by Canibul

What are you guys recommending for a good crimper? I've been unhappy with the 'stamped from flat sheet' cheapo crimper/wire stripper/small machine screw shearer I got at local hardware store. I've been using a crimper made for wire leaders instead, and essentially folding over a section of small copper tubing with a twisted wire connection inside. Then I turn it 90 deg. and crimp again. It's slow and take some time to get it right because it's the wrong crimper for the job. I see Amazon has ratcheting crimpers from $21 to over $80. Any recommendations?
I got a lot of crimping yet to do.

I use a Swedish Pressmaster tool. Cost about $150 (IIRC) and worth every penny. I have stress tested the connections, using good terminals (Molex etc.), and the wire breaks before it pulls out of the terminal. The wire and terminal are virtually welded together. With no solder wicked up the wire, the wire retains all its flexibility, so won't break if flexed.

The terminals I use are heat shrink, so no copper is left exposed to salt air.

In my opinion, this is the right way to do it.

Note that good crimpers need to be calibrated from time to time, if you're doing a lot of crimping.

[wingless]

Originally Posted by Ex-Calif

Nasa says avoid it

Originally Posted by wingless

Here is the NASA specification defining their requirements on soldering properly.

Originally Posted by Ex-Calif

I didn't say NASA prohmibits it. They have specific criteria for when it can be used.

You posted the how to spec. A couple weeks ago in a different thread I posted the when to spec.

Did you read the spec you posted? I did not see anything about joining two wires...

My review of the NASA specification does not state that soldering wire should be avoided.

Sorry for the incorrect link posted previously, the correct link is now provided, showing the NASA how-to use solder to join wires.

Also remember that while NASA standards are great, very few boats will be subjected to the rigors of interstellar travel. It is not expected that any Earth marine vessel ever will be replaced by V'Ger, regardless of the boat's wiring quality.

[Ex-Calif]

Originally Posted by wingless

Also remember that while NASA standards are great, very few boats will be subjected to the rigors of interstellar travel. It is not expected that any Earth marine vessel ever will be replaced by V'Ger, regardless of the boat's wiring quality.

On that we definitely agree. Pulling out specifications in forums is basically "who can google faster."

People are gonna solder or crimp based on what they wanna do.

Less than 1% will do it the FAA way or the NASA way.

We aren't wasting spending billions of dollars to put a man on the moon...

But I have seen a lot of messed up soldering and a lot of messed up crimping...