Solder vs. Crimp vs. Both

[Figment]

Nathan's uninsulated terminals post got me thinking about soldering vs crimping vs belts-and-suspenders.

Right off the bat, I don't understand why anyone would use non-crimpable solder terminals. My experience with these is that (unless working on a bench) it's impossible to keep the terminal properly positioned while heating. Ya gotta crimp a little just to lock the two together.

So really the question is about the benefit of soldering a crimped terminal?

To my way of thinking, the benefit of soldering a crimped terminal is that (years down the road) the solder eliminates the corrosion on the surface of the wire, which progressively reduces conductive contact area, building resistance (heat), causing voltage drop, etc. I would swear that I've seen empirical data to this end, but most of my books are packed so I couldn't find it last night. 12-volt bible? something by Don Casey perhaps?
Anyway, my point is that the crimp is there to hold the terminal while soldering, and to hold things together if the solder should embrittle and fracture. The solder is the long-term connection.

The key there is "long-term". I'm not going to lie and say that I solder everything on my boat. I don't. I solder most connections. Let's get real.... soldering is time consuming, messy, and (I don't have a butane iron) inconvenient because it's shorepower dependant. My rule is to solder:

-Anything I expect to last more than a season.
-Anything hypersensitive to voltage fluctuation (instruments, etc)
-Anything carrying 5 amps or more.
-Absolutely anything in the bilge or engine compartment. (though I avoid terminal fittings in the bilge)

I gather that I'm in the minority on this. Most boaters I know don't even know how to solder. I'd be interested to hear from others about what they actually do on their boats.

Heatshrink.... now there's another ball of wax...

[David]

I agree with you that many boat owners just crimp and I am one to crimp, solder, and heat shring tube the terminal. I think it is the best defense against corrosion. Also, I would verture to guess that many who are soldering are using acid core solder instead of electronics-quality silver solder and doing more damage than good.

If done right using the right technique and right materials the wiring will be as bullet-proof as it can be.

[dasein668]

My feeling is: in a perfect world, yeah, crimp and solder. On the other hand, my boat is just now starting to show real wiring issues (hence the upcoming gut-job) and lemme tell ya.... the wiring is horrendous! Poorly executed crimps, with no heat shrink, and exposed, corroded wire. Yup. Miserable.

BUT, the wiring is still functioning. Yes, ugly, and potentially dangerous, but still workin.'

So.... what to do? I think that a properly crimped terminal, with well-applied adhesive-lined heat shrink tubing, strong mechanical fastening, drip loops, etc. obviates the need for solder. Yes, solder may give you that little bit of something extra, but a properly heatshrinked crimp connector is pretty good insurance against corrosion. As much as anything else, I'd say. When I do the boat, I'm going to go with PROPERLY crimped terminals with well-applied adhesive lined heat shrink.

I guess my feeling is crimped and soldered is not bad, but probably not completely necessary either, provided that high-quality materials are installed correctly, and with care.

[David]

I suppose the rule of thumb I use is this: For a high amp wire to a battery post or to a distribution post, would you simply crimp it or would you crimp AND solder and heat shrink, etc. In all cases I would solder high amp runs to lower the resistance as much as possible and know that in the middle of a storm when things are flying around that wire isn't going to come loose. Since I apply the rule to high amperage wires, should I do no less for low current wires where resistance is even more critical--wires that are powering critical systems onboard? Having said all that it required completely rewiring the boat to follow my own rules.

Crimping versus soldering will always be a controversial issue, especially with older boats.

[dasein668]

I would argue that from a mechanical strength standpoint, if a crimp is going to fail, a soldered joint certainly would too. Again, its a question of proper installation. A properly crimped terminal is mechanically stronger than a solder joint.

In terms of resistance, yes, a soldered joint will have somewhat less resistance to current. My feeling is that this is the only really strong argument for soldering.

Absolutely, a soldered joint will give you "that little extra" but my feeling is that it is not critical to a good installation. And for me, the arguments against it--messy, time consuming, challenging to properly execute aboard a boat--outweigh the benefits, especially for a boat used primarily for daysailing and coastal cruising, as most of our boats are.

I'm not saying one shouldn't solder. Only that I'm not going to.

[Tim]

In an age of high quality crimpers, tinned copper wire, and excellent adhesive/waterproof heatshrink material, I believe soldering is unnecessary and without particular benefit. I don't believe it should ever be used as a stand-alone method. Can it be used in lieu of heatshrink waterproof material? Not a fan, myself. Does it add to the quality and strength of a crimped, heatshrinked connection? Debate to your heart's content; I don't have the answer. In my opinion, it's unnecessary and adds no particular value.

A good crimped connection on properly-installed tinned wire will never come apart, and when covered with properly-applied heat shrink, corrosion should not become an issue. Test every crimp by pulling on the wires. It's annoying when sometimes they come apart (and they do), but if it comes apart this way, it means that it was not properly installed and therefore it would have only been a matter of time before it happened at an inopportune time. If the crimp holds when the wires are pulled in this manner, it's highly unlikely it will ever fail down the road.

Neither connection method makes allowances for improper installation, of course; mere sloppiness/improper installation practice accounts for 90% or more of failures seen in the real world. Most boat wiring that I see defies description in its badness.

I believe there no reason to ever run wires through the bilge, except for the bilge pump. There are always other ways, and it's worth the effort and extra time to find and use them. Boatbuilders place equipment in the bilge because it is easy and saves time. That means more profit, and/or a lower starting price for that boat model. When faced with the option of placing wiring or electrical equipment in the bilge, stop and consider other locations. I'm hard pressed to think of a time when no other option will be present (except for bilge pumps).

The long and the short of it is that one must do what makes oneself comfortable and satisfied with their own work.

[Figment]

I'm not trying to beat up on you, Tim. You just happened to be the most easily quotable....

...I don't believe it should ever be used as a stand-alone method. Can it be used in lieu of heatshrink waterproof material?

Couldn't agree more on the stand-alone issue.
Heatshrink is likewise a no-brainer. Always heatshrink.

...when covered with properly-applied heat shrink, corrosion should not become an issue.

On this I disagree. I've had heatshrink-protected connections suffer alarming corrosion. Perhaps my application technique is deficient.

mere sloppiness/improper installation practice accounts for 90% or more of failures seen in the real world. Most boat wiring that I see defies description in its badness.

Amen to that. When I bought Figment, much of the boat was wired with LAMP CORD, twisted&taped connections.

I believe there no reason to ever run wires through the bilge, except for the bilge pump.

again, Amen. I would further testify that bilgepumps should be hard-connected with a twisted, soldered, direct wire-to-wire connection, protected with heatshrink. but then, I'm a solder nut. :)

Indroducing yet another semi-debatable issue: Heatshrink.

Let's face it, this stuff ain't cheap. Or, I should say, I have yet to find an economical source. I'm constantly fighting the urge to skimp with heatshrink.

I use it as a measure of corrosion protection, but primarily I use it as an insulator. I'm a bit of a nut when it comes to the potential for current to start jumping where we don't want it to jump. My battery cable terminals are an overzealous example..... After applying heatshrink to two of my terminals, I had to actually cut some away to expose enough metal for the fitting to sit properly on the terminal bar.

I think it's Don Casey who proposes the guideline of a full inch of overlap onto the insulated part of the wire. On a bilgepump direct wire-to-wire connection, for example, that uses a full 3" section of tubing. Assuming that you wreck one section somehow (I usually do) that means that a bilgepump installation uses a whole $5 pack of tubing! That kind of thing adds up really quickly when rewiring an entire boat.
When applying to a typical stake-on or ring terminal, I generally snip the store-bought length of tubing into three sections, which leaves about 1/4" of overlap onto the unviolated insulation.

Am I the only skimper in the bunch?

[Dave, 397]

I buy it at the local commercial hardware store...it's between 2.80 and 4.00 for a 3-foot stick depending on diameter.

Dave

[David]

The long and the short of it is that one must do what makes oneself comfortable and satisfied with their own work.

Amen to that!

[JetStream]

Just a couple of clarifications for the good posts already presented:

Any crimped terminal that is done properly (i.e. ratchet crimper with proper dies) will form a gas tight joint that is every bit as good as solder, and have a low resistance as it entails cold flow of the tinned copper inside the joint. If solder is used (only in addition to a good crimp - not in lieu of), you must allow for some additional support of the wire as it can break from vibration where the solder has wicked up the wire strands. Even good quality electronic solder uses rosin flux that is hygroscopic (absorbs water) and should be cleaned before applying the heat shrink.

For heat shrink, it is extremely important to be sure there is no air left in the connection. Trapped air = trapped moisture = corrosion. In the old days, we squirted a little RTV into the connection before shrinking. Nowadays there is quality heat shrink material available with an adhesive wall. When it shrinks, you get a nearly impervious joint that is very bullet proof. An added advantage is gotten by using white or other color coded heat shrink, where you can mark the wire's function with black permanent marker.

[David]

Any crimped terminal that is done properly (i.e. ratchet crimper with proper dies) will form a gas tight joint that is every bit as good as solder

I would disagree about such a connection being air tight. Crimped connections will wick up salt water and give you green fuzz in a couple of days. It is anything but air tight. The combination of proper solder to a crimped connection and properly sealed with shrink tubing will give you the best defense against salt air and moisture. Furthermore, if you are supporting the wire every 18 inches per ABYC then there is little change for vibration and movement.

[JetStream]

I figured that I might generate a little typing activity when I sent in the post about gas-tight joints. The only reason I can stand behind my post about the gas-tight integrity is my earlier work as an electrical engineer producing panels for the now disappeared nuclear industry. Their specs were mil and higher. I have personally done pull tests etc. on proper joints and can attest to the integrity. The only time I have seen crimps fail, (and the soldered ones failed as well) was in high temperature cycling where the connection extruded from the crimp unless the crimp (connector) content was all nickel. The real problem arises when the homeowner doesn't have the proper crimp tool and doesn't get the cold flow that is required. If that is the case, I endorse soldering plus crimping as long as adhesive lined heat shrink is added for wire support.

All of the above views are also endorsed by ABYC.

May your connections be as fair as your winds.

[Guest]

Why is heat shrink better than using a liquid electrical tape such as that from Home Depot available in assorted colors for around $5 a can? Or why not use a dab of polyurethane sealant? And what about terminal ends - you can't effectively heat shrink some of those types due to plastic covers and their tip shape? Liquid sealants may sometimes be unhandy to wait for drying, but it's not always handy and certainly more costly to use heat shrink.

I've used either heat shrink or liquid sealants depending on the job.

James384

[Figment]

I quit using "liquid electrical tape" after I had an application chafe through really quickly on a connection that wasn't even particularly chafe-prone. Perhaps a few more coats would've been in order, but I lost faith and swore off the stuff.
And MESS!!! gah! At least drips of solder pop free with a little bit of ice, once you dribble that goop onto something, I've found that it's a real pain to cleanup.

So.... I think that if this thread has taught me anything, it's Different Strokes for Different Folks. Solder, crimp, heatshrink, liquid..... it sounds like we each have our own favored methods.
In my experience, the thing about using a "favored method" is that one's work quality is likely to be far higher than if one were to adopt a "foreign method".

Of course, the above only holds water as long as one's favored method isn't "Twist-N-Tape" or (hey, we've all seen it...) wire nuts. ;)

[Ray Henry]

Well, I don't think it takes THAT much more time to crimp AND solder. Regardless of the benefit arguments, it's got to be better than either one alone!

Also, for those that use heat shrink -- here's what I do. Just after slipping the heat shrink down over the crimped and soldered connection and before applying the heat, I squirt some silicone caulk (squeeze tube with a VERY narrow cut tip) into BOTH ends of the heat shrink. Then apply the heat.

This guarantees me a water and air-tight fitting for about 5 extra seconds of work. That way you don't need three inches of overlap, either.

All of these were crimped and soldered:



For my battery lug connections (2/0 gage), I used a lug crimper onto the wire, then drilled a 1/8 hole in the end of the lug at the sloped part giving access to the wire ends. I used a torch and heated the lug (and thus the wire tips) and fed solder into the hole util it wicked up the wire and filled up the cavity remaining in the lug terminal.

Then I heat-shrunk (?) with the added silicone the whole affair.



That's what I do. Sorry, didn't mean for this to be a diatribe.

Ray (newbie on the forum)