To Solder or Not.. That is the Question

[travellerw]

So... I came across some information recently that shocked me.

The ABYC does not allow solder as the sole means of electrical connections (funny even NASA supports this). Further research then showed that most people do not solder and simple rely on crimped style connections.

This seems to go against all my experience in other industries (automotive, small engine, ATV). When I make connections (especially on an ATV) I will crimp the connection, then solder, then cover with "sealed" shrink tube and finally cover with longer shrink tube (non sealed) for strain relief. Been using this method for 5 years or so and have never had a single failure (in 1000s of connections). I can only imagine that an ATV would be a harsher environment then a boat. Those connections are subject to high vibration due to high engine RPM, plus continual dunking in nasty liquids (marsh/bog water).

I've had some people comment that I "go to far" when it comes to connections, but I disagree. Anyone that has chased down an electrical fault will know what I mean. The time and heartache is worth spending a little time making sure the connections I make are bulletproof.

So my question to you... Do you solder? Do you use "sealed" shrink tube?

and a bonus question... Do you use tinned wire?

[goboatingnow]

Originally Posted by travellerw

So... I came across some information recently that shocked me.

The ABYC does not allow solder as the sole means of electrical connections (funny even NASA supports this). Further research then showed that most people do not solder and simple rely on crimped style connections.

This seems to go against all my experience in other industries (automotive, small engine, ATV). When I make connections (especially on an ATV) I will crimp the connection, then solder, then cover with "sealed" shrink tube and finally cover with longer shrink tube (non sealed) for strain relief. Been using this method for 5 years or so and have never had a single failure (in 1000s of connections). I can only imagine that an ATV would be a harsher environment then a boat. Those connections are subject to high vibration due to high engine RPM, plus continual dunking in nasty liquids (marsh/bog water).

I've had some people comment that I "go to far" when it comes to connections, but I disagree. Anyone that has chased down an electrical fault will know what I mean. The time and heartache is worth spending a little time making sure the connections I make are bulletproof.

So my question to you... Do you solder? Do you use "sealed" shrink tube?

and a bonus question... Do you use tinned wire?

Well to ignite the war....

A proper crimp is gas tight. It is far more resilient that a soldered one, as soldering creates a hard point in the otherwise flexible strands, leading to failures

If you examine your cars wiring loom, you will not see soldered crimps.

I stress the term " proper crimp". The main problem with crimps is that people use cheap or crappy crimps and even crappier tools. A proper crimp tool is an expensive tool and is tailored to a manufactures set of crimps.

IN my long experience as an engineer, crimps are generally superior to soldered connections, especially where movement or vibration is a factor.

Adhesive lined shrink tubing is not a good guarantee of anything really. It may not render the fitting waterproof, nor may it actually add much in the way of strain relief to the cable. Good crimps come complete with mechanical strain relief that physically grips the cable.

Personally I use good quality uninsulated crimps and then cover with a cable marking cover. Sometimes I use an adhesive lined, primarily to just keep the cover in place. Personally I prefer crimps I can inspect, rather then buried under an adhesive cover.

I don't think NASA supports soldered crimps, I worked in the defense industry and they didnt.


I personally have a Europeans view on tinned wire !!!
dave

[Greenhand]

What you describe does not use solder as the sole means of connection, either. Why would it surprise you that ABYC does not allow it?

I believe crimping is easier for a DIY to master than soldering.

The wiring that my electrician told me is probably original (1987) has a crimp connecting all the cabin light wires where they come into the distribution panel. No solder, no shrink wrap, just a crimp.

When you say "sealed" heat shrink, do you mean the adhesive lined?

My preferred crimp connections have the built in heat shrink.

[transmitterdan]

I don't know what NASA group you worked with but my experience is they do not allow solder as sole means of supporting a wire connection. Even where solder is permitted the wire must remain fixed in place without the solder. No standard I know will permit a solder connection where but for the solder the wire would fall off/out.

[phorvati]

Crimping is only more resilient due to vibration prone environment.
Solder gives lower resistance, prevents salt, moisture and dirt from penetrating the crimp and impeding the flow of electrons, and it would be better if it were not for vibrations.

If crimping was better circuit board components would be crimped and not soldered.

[Canibul]

I've now replaced dozens of old wire connections on this boat I'm working on. I've seen everything from wire nuts to solder joints by previous owners. I, too, came from a background in which we first tinned wires, then soldered them. But what I've seen on the soldered joints that have been in this boat for over 20 years has changed my thinking. I don't know whether it's the different metals, or the acids/resin core solder or what ,but the soldered joints look terrible, and the wire often has mechanical and corrosion problems adjacent to the solder. The best stuff I've seen was all higher quality butt joints.

I've stopped using the aluminum butt joints, and started making my own out of copper tubing. The really small stuff they use for gas pilot lights works really well. I cut it up a batch at a time with a Dremel. I figure the copper to copper connection, well insulated and supported, should be a good crimp.

[travellerw]

I was pretty sure there would be tons of opinions on this one.. So here is a couple of things to clarify.

1. Yes you are correct, crimping then soldering does meet the ABYC standards, just not soldering alone.

2. I was vague about the NASA thing. It is correct that the wire must be supported by other means.

3. Yes I mean "Adhesive" lined shrink tube.

Although I have a background in engineering, my opinion is based on experience. The company I own does repairs/warranty and upgrades in motor sports. The most common failure (by far 10 to 1) are crimped wiring connectors. These include everything from crimps done by the customer (cheap stuff) to manufacture crimps from the factory. Not all failures are due to crimping though, some are due to failed plastic housings on push together connectors.

In any event, the method I described above has been bulletproof for me under some very rough use.

I also 100% disagree that shrink tubing provides little to no strain relief. A double shrinked connection (with double wall tubing) will be as strong as anything else IMHO.

P.S. Yes the proper solder is also crucial. Acid core solder has no place around wires.

[goboatingnow]

Originally Posted by phorvati

Crimping is only more resilient due to vibration prone environment.
Solder gives lower resistance, prevents salt, moisture and dirt from penetrating the crimp and impeding the flow of electrons, and it would be better if it were not for vibrations.

If crimping was better circuit board components would be crimped and not soldered.

I must disagree. a proper crimp results in a gas tight connection , note that a gas tight connection between the relevant metals is fully watertight.

Soldering unless done very well, does not necessarily prevent moisture from entering the joint. But it definitely does weaken the strands creates corrosion sites and other issues.

Circuit board components are soldered because primarily the method suits mass production, is cheap and can be mechanised.

Do you think a major company with a reputation like AMP creates crimes that needs soldering !!!

crimps correctly applied, provide for a low resistance connection, and with the added security of mechanical strain relief.

Note I exclude all those cheap plastic crimps you buy in an auto parts store and crimp with a $5 hand tool - pure junk.

dave

[transmitterdan]

Originally Posted by phorvati

Crimping is only more resilient due to vibration prone environment.
Solder gives lower resistance, prevents salt, moisture and dirt from penetrating the crimp and impeding the flow of electrons, and it would be better if it were not for vibrations.

If crimping was better circuit board components would be crimped and not soldered.

Soldering a wire into a lug is only slightly better than a bad crimp. Even then it's a race to see which one will fail first.

Circuit boards don't use crimp because generally there are multiple solder joints per component and very little vibration happens at the solder connection. If the component were allowed to vibrate the solder joint would fail rapidly. Also many (nearly all) surface mount components are securely glued to the board prior to soldering. Those that cannot be glued are secured by other means. In the old days of circuit boards with through hole components the military specifications called for some of the pins to be clinched over so the component could not fall out before soldering. They did not allow the solder to be the sole mechanical fixing means.

It is a fallacy that solder has lower resistance than a crimp. Solder has much higher resistivity than pure copper. A proper crimp is a gas tight metal to metal bond and no ordinary solder will have lower resistance. A gas tight crimp will not permit salt or moisture to intrude on the connection.

63/37 tin-lead solder has resistivity 0.145 micro-ohm-meter. Copper has resistivity 0.0168 micro-ohm-meter. Copper is almost 10 times better than ordinary solder. The only solder that comes close to copper is Indium/Silver or pure Silver which no one can afford and are difficult to apply properly.

[JK n Smitty]

My "go to" source for information on marine wiring is Maine Sail/Compass Marine. He did a really good how to article on marine wire termination where he did some strength testing. In one he found that a properly crimped 12 gauge wire would support close to 95 pounds while just shrink wrapped will only support 10-16 pounds. He then did a more scientific based test comparing crimping tools where he found quality crimps to hold up to 193 pounds.

IIRC, Maine Sail has said that soldering is ok when done by someone that knows what they are doing but it is kind of a lost art. That is one of the reasons he is not generally in favor of the connection. With good tools a crimp connection becomes easier to perform well.

Personally I crimp and use adhesive shrink wrap. But as Stu says, your boat, your choice.

Jesse

[lonesoldier0408]

Cannibal,
Thanks for the copper tube tip. I'll definitely give it a go in the future. What are your thoughts on dielectric.? What are your thoughts on dipping the tip of the crimped connection in molten solder.? I use liquid electrical tape on connections exposed to the elements.

[MarkSF]

Originally Posted by Canibul

I've stopped using the aluminum butt joints, and started making my own out of copper tubing. The really small stuff they use for gas pilot lights works really well. I cut it up a batch at a time with a Dremel. I figure the copper to copper connection, well insulated and supported, should be a good crimp.

I'm not sure what you mean by aluminum butt joints. The crimp butt joints from Ancor et al are tinned copper.

[levm]

I support Travelrew wholeheartedly. One can philosophize forever about the relative resistance of this metal or that. My experience is that just crimping or just soldering will cause problems down the road (usually at the worst moment).
Solder crimp and cover with heat shrink tubing is the only ticket for a peace of mind.


Sent from my iPad using Cruisers Sailing Forum

[travellerw]

"JK n Smitty" That was a very insightful response, exactly what I was looking for.

I agree %100 on anything from "Maine Sail". His posts/experience are nothing short of gold.

Thank you...

[Dockhead]

Originally Posted by levm

I support Travelrew wholeheartedly. One can philosophize forever about the relative resistance of this metal or that. My experience is that just crimping or just soldering will cause problems down the road (usually at the worst moment).
Solder crimp and cover with heat shrink tubing is the only ticket for a peace of mind.

Sent from my iPad using Cruisers Sailing Forum

My experience is different - joints with solder in them are brittle and fail quickly by the wire breaking off. A good crimp (technique plus a $100+ tool plus Molex or other top quality joints) is bomb-proof. No theory - just my personal experience, FWIMBW.