Wire joins: solder vs. butt connector

[Brian D]

FWIW, airliners use crimped connections 99.9% of the time. The FAA has found that soldered joints are prone to failure due to vibration. I use the uninsulated butt crimps with heat shrink as mentioned above in any car I work on.

George, I know Luke was kinda subtle but I would never use the scotch locks in any of my cars. I've pulled the wiring out of quite a few old cars and those things always (always!) have a lot of corrosion in them and in some cases I have seen them melted a bit, indicating a lot of resistance in the connection. No bueno, my friend.

[s_ribs]

Luke-

The one thing making me completely cool (and perhaps leaning towards some days) is that manufacturers use some sort of crimp connection for everything except computer boards! The only solder I see is in conjunction with a crimp (ex: battery clamps).


I am curious how proper heat shrink tubing affects life-time of soldering? On important connection points in the engine bay I use adhesive lined tubing regardless of solder or crimp connection.

[jeffw]

I saw Luke's post a while back - I know what you're referring to.

Luke is wrong. (sorry Luke!!!)

But, he got me thinking about it - so I started asking a few people. I asked two MIT engineers (one that works building medical devices - crazy stuff) And I asked a third engineer that is an actual god damn NASA solder instructor.

All of them said that it's fine and normal practice to solder wire. The only time there is an issue is then you don't have the wire supported and it does a ton of bending right next to the solder joint. Basically - anything on your e30 will be fine. Any quality solder made for electronics is fine - solder till your heart is content. NASA requires RMA solder, and that's what all the wiring that is soldered on the space shuttle uses.

I'm not really a fan of butt connectors either. You're suppose to do a 5 pound pull test after you splice them - and you should be fine. I'll tell you something I've become a HUGE fan of - these "quick splices". I buy them from 3M by the 100's - and like everything else 3M makes - they are kinda awesome. Really easy to tap(t-into) or extend a wire. You can remove them with a screwdriver it's almost like they were never installed. Once removed there will be a small nick on two sides of the wire's insulation that usually closes up on it's own. Or a bit of electrical tap on the wire if you're really worried about it. But much better/faster/quicker than a butt connector.

Give them a go - almost any hardware store sells them. I've started including them in the gauges I sell cause they just make such a good connection, carry tons of current if need be, and don't f-up your wiring. Not as good as soldering - but great when you need a quick splice and don't want to hack into anything.

I only use butt connectors but thats cause i been working with andy lol. and I must say graves these t taps, in my opinion, are crap. they work well for a wire or two but i would never use them to do a full install.

[matt]

I am with Luke.

I will crimp every time over soldering.

[StereoInstaller1]

If any of you could show me a solder joint that has been in a car for more than 5 years that isn't corroded I might change my opinion...but butt connectors still win, especially in the professional world, where seat/dash/carpet burns and soldering while upside down etc make it damn near impossible to get any work done and maintain quality.

You guys have to remember that the average solder job is crap, as is the average crimp. A proper crimp (and EVERY SINGLE crimp of mine passes the 5lb test, unless it is 20ga or higher wire) is best IMO, but as far as typical hackery, I will take a hacked crimp over a crappy solder joint any day.

If you are one of the rare few who can solder correctly, have at it. Having taken apart hundreds and hundreds of solder joints and seeing how none of the manufacturers use solder on any wire tells me my proof is still correct. I am all about learning something new though, so shoot me a link to this new "non corrosive" solder/flux.

And George...fucking scotch locks? What bullshit is that? Maybe if you are dealing with .5A or less, but if you are running ANY kind of power through that you are an absolute fucking retard. Microscopic contact area, piss poor oxidization resistance, etc...scotchlocks are crap. I have seen so many of those actually melted from "out of spec" use...well, I just do not do bullshit like that, ever.

Luke

[s_ribs]

I've come to prefer soldering... but only do it if you learn to do it properly!! Seriously, soldering takes time to learn - a bad connection is a bad connection. Done right they are good connections and aren't bulky so things stay clean looking.

When I need something quick (or I don't trust my soldering skills) I have shifted to using uninsulated butt connectors. I like to put heat shrink tubing on my joints, and uninsulated connectors are much thinner/bulky than insulated ones. Also, from what I understand butt connectors are better in high movement or vibration areas.

Vampire clips... I hate 'em! Great for testing before cutting up wires though. ;)

[nmlss2006]

Thanks George and Jean! I'm glad to know I'm not the only one who's.. not a fan of butt splices. And I hear what you're saying about possible fraying of the wire at the end of the soldered piece, but I agree, in an E30 that should not be a problem, except *possibly* for solder joins that were in exactly the wrong place on the engine harness (some wires do move as the engine moves). I like the 3M connectors, though I have to wonder how well they work and if they weaken the wire by cutting it? I'll trust your judgement though :).

[george graves]

EDIT - Luke thinks 911 was an inside Job, and that the moon landing was a hoax. I'll just let that preface that to this conservation.....Also his "corroded solder joint" argument is totally invalid. This is his red-neck customers that soldered wires with "plumbers copper pipe" solder and/or flux. Not electrical solder. Yes, that will mess up stranded wiring in a hurry. So sorry Luke, wrong again. And if you really want to know all his "PNC" crossovers that he sells, they are all soldered. Every joint is a solder connection. So yea.

-----------------

I saw Luke's post a while back - I know what you're referring to.

Luke is wrong. (sorry Luke!!!)

If I was installing stereos for a living - I'd use them, they would save time, and let me move more cars. But they are far from "best practice" - if it's you own car, take the time to do it right.

But, he got me thinking about it - so I started asking a few people. I asked two MIT engineers (one that works building medical devices - crazy stuff) And I asked a third engineer that is an actual god damn NASA solder instructor.

All of them said that it's fine and normal practice to solder wire. The only time there is an issue is then you don't have the wire supported and it does a ton of bending right next to the solder joint. Basically - anything on your e30 will be fine. Any quality solder made for electronics is fine - solder till your heart is content. NASA requires RMA solder, and that's what all the wiring that is soldered on the space shuttle uses.

I'm not really a fan of butt connectors either. You're suppose to do a 5 pound pull test after you splice them - and you should be fine.

[Jean]

I hate butt connectors with passion, so I always kester solder and use heat shrink over the soldered connection for a good electrical/mechanical connection that also looks clean.

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=370-080

[nmlss2006]

Luke especially has been very negative on solder joins because of corrosion from the flux residual in the soldering. I was, however, under the impression that modern solder spools with RMA rosin cores did not have oxidation issues - whereas the 'normal' RA core does. Could someone shed light?