To DIY'ers-how not to wire things

[jkstill]

Originally Posted by joff

When you crimp + solder, your crimped connection now contains the brittle solder/copper alloy. All you did was waste time and a perfectly good crimp on a soldered joint and you didn't even save any time.

I appreciate the input. I've had a few years practice and do know how to solder.

The issue of not soldering a crimped joint doesn't seem that clearcut.

Here's a couple articles, one clearly against the practice, and one that tells how to properly do it. Granted, the second article is for larger wire than you will probably find in a car.

It may or may not apply to smaller wire.

http://www.ch601.org/resources/crimpsolder.htm

http://www.connex-electronics.com/?u...imp_guide.html

Personally, that's all the time I have to spend on looking up info on it.

Anyone else have anything?

[joff]

Originally Posted by jkstill

I appreciate the input. I've had a few years practice and do know how to solder.

The issue of not soldering a crimped joint doesn't seem that clearcut.

Here's a couple articles, one clearly against the practice, and one that tells how to properly do it.

Good info.

Yeah, I agree its definitely not clear-cut. :-) There are places for both.

I remember hearing NASA mostly uses crimp connections because anybody doing a solder joint has to be certified. A good crimp connection that is 99.9% the same as a solder joint is easy to make with the proper tool, proper hardware and proper prep and requires no skill (which is usually good for quality).

Being in the electronics industry though, its hard for me to imagine there being any question as to the reliability of soldering. We employ 3 full time soldering professionals for prototypes and repair work and have product lines with 20 years of production history and 100s of thousands of boards built so one can imagine the cumulative reliability data acquired. If there was anything wrong with solder joints, we would see it in our repair dept and in production yield stats and I'd be (as well as the rest of the industry) trying to find alternative ways to manufacture electronics.

Some further useful facts to contribute:

One of the biggest surprises to be learned about soldering is that rosin flux residue becomes corrosive at high temperatures. It is very important to clean the solder joint (acetone works best). It is not apparant immediately, but over the course of several years an invisible amount of flux can eat heat shrink, wire, and cause problems.

Also, the electronics industry recently got hit with B.S. (IMHO) Eco-legislation (RoHS) that requires us to take the lead out of solder. Soon it may become difficult for Joe Blow to get leaded solder which is superior in every way to the new "Greener" solder. Without the lead in solder, a phenomenon called "tin whiskers" causes solder joints to grow metal "hair" which can cause shorts to anything nearby. They take many years to grow such that the real hit to electronics reliability probably won't be known for 5-10 years. It also requires a hotter iron, easier to make a cold joint, doesn't flow as well, and is more expensive. It is also interesting to note that high reliability industries such as military and aerospace, have been given convenient exceptions to this new lead-free solder legislation.

[REVIT93RX7]

There are tools for every application. It is a matter of determining the environment one is using the wire in. Crimping will work is some applications and solder works for others. In the auto industry I think either one is fine. It just comes down to the skill of the person doing the work. Space I think is some cases dictates which method to use. Solid wire verse stranded wire is also an issue.

[scotty305]

I agree with joff. Most people who dislike crimping have probably seen the results of low-quality crimp connectors and tools used by people who haven't got much experience using them. With the proper equipment and training (or even plenty of trial and error), it is much easier (and faster) to make a very reliable crimped joint.


I have seen soldered joints in which the wire near the solder literally corroded and crumbled away, they were at least 3-5 years old and you could see yellow/brown traces suggesting that the flux had not been cleaned (I'd suggest using rubbing alcohol applied with a stiff-bristled brush, and then a rag to wipe clean). The solder joint was still intact but the wire immediately adjacent (where the flux had flowed to) had corroded and broken and there was lots of powdery residue.

There is a thick plastic-like heat shrink material (I think it's called SCR) that will do a better job of insulating and protecting joints (whether they are solder joints or crimped splices) compared to regular thin heat shrink. Dual-wall (adhesive) heat shrink is nice also.

If you are using cheap auto-parts-store crimp connectors (butt splices) with plastic surrounding the metal, heat the plastic up before crimping (use a heat gun if possible, or by breathing warm air on it if that's all you've got). Use the notched end of a universal crimp tool; the color-coded "insulated" crimp tool sections that are perfectly concave on both sides won't distort the butt splice enough and it won't grab the wire well enough.

That said, I've soldered more than a couple electrical connections in cars and haven't seen or heard of one fail yet; maybe I'm lucky. When possible I try to use crimps.

[jkstill]

Lots of good info here.

I hadn't considered the corrosive properties of flux.

I'm also familiar with RoHS- the company I work for designs electronic systems for cell phone and medical use. As you say, getting solder may become a problem.

Maybe it's time to invest in some high quality crimping tools.

[albertomg]

SO since we are on the topic of crimping.. I can't solder to save my life. B/c of that, crimping would be more reliable for the few times that I do electronics. Can one of you knowledgeable folks recommend a good crimping tool and crimp connectors?

A link to the products would be great.

Thanks.