RadioMan
Recruit
That quote is by JiFaire from another Place, at another time. Having been putting wires together professionally for 40 years now, his post bothered me and I told him so. However, his logic is quite sound and is discussed below.
Jim & I have been discussing this offline for a while now and I believe we're in agreement to the following:
IF you're going to solder the wires heed the above warning to use rosin-core solder! NEVER use acid-core solder, or flux, on anything electrical!!!
Also keep in mind that most solder is a combination of lead and tin, neither of which is a very good conductor of electricity. Make a good, mechanically and electrically sound, joint first - The solder is just there to keep the joint from coming apart - Period. Heat the wire (not the solder) and flow the solder into the joint. Always obey the 3 Second Rule. If you have to keep the iron (or gun) on the joint for more than 3 seconds you don't have enough heat to do the job. This is very important because what's going on is the wire (in this case) is sucking the heat from the joint. Obviously this is heating up the wire beyond the joint. Common wire is soft drawn copper. When you heat it up enough it becomes hard - heat it enough and it becomes glass hard. A bit of vibration and it will break, usually right next to the joint. Getting a proper soldered joint actually takes practice and the correct iron or gun and solder size for the job. There is also silver bearing solder available. It takes a lot more heat to get a clean joint with the silver, which will get the wire glass hard in the hands of almost anyone without a bunch of practice. If you’re not quite adept at soldering, I would avoid it and stick to 60/40 Rosin Core Solder.
That being said. You'll notice that all wire connections from the factory under the hood are crimped, not soldered... In fact, the major electrical trouble spots under the hood are soldered devices - The FSD and module for the wipers come to mind right off. In any area where heat and/or vibration are a concern crimped connections are the electrical industry standard.
So why do knowledgeable folks, like Jim, recommend soldering over crimping?
Here's the rub: You can goto WallyWorld, or places like that, and get a crimp connector kit. This is what most would do. This stuff is junk and will cause all kinds of problems later... Even though soldering a wire splice is almost always inferior to a crimped splice, using the wrong stuff negates any advantage that crimping gives the connection and will bite you sooner or later. You might just as well take your chances with solder.
I used to teach soldering - there's actually some art to it as well as the mechanics of doing it right. Crimping, on the other hand, pretty much just requires the right tool, connector, and orientation of the connector in the tool.
A good, permanent, crimp connection must be made with the right hardware and tool. The common stamped metal tool with the wire stripper built in is NOT the right tool. You can get a real crimping tool at almost any electrical supply house. I've also seen good crimp tools at Home Depot and Lowes. They are forged steel and actually designed for crimping (and occasionally cutting) wires. The forged tools keep the hammer and anvil alignment straight, while the stamped tool allows them to wander about a bit – This is not good.
Personally, I hate insulated crimp connectors. While there are some good ones out there (soft nylon insulation), the type with the hard plastic insulation (usually PVC or hard nylon) is very hard to get a good crimp with, and you can’t see the joint. If they are all that’s available I always remove the insulation. The other problem with them is that there is only one correct way to put the connector into the tool. You can’t see the seam with the solid color insulation very well. If you use quality, uninsulated connectors that are properly sized to the wire you’re splicing and crimp them correctly with the right tool you will always get a better, more stable splice than you can by soldering.
I always put a bit of NoAlOx on each wire before inserting it into the connector and then rub on some non-acidic silicone on the joint before putting some heat shrink over the joint. This gives you a corrosion proof connection. NoAlOx is a trade name for an anti-corrosion paste. There are several others, anyone of which will work. Home Depot, Lowes, and others carry similar products. They work on a molecular level, so just put on enough to coat the wire and rub it in. A big glob is counterproductive. I’ve made thousands and thousands of splices and terminations and am still using the same tube of the stuff that I bought in like 1980. The stuff should also be used on all of the terminals to ground. Again, just a light coating is all that is necessary or desired. BTW - Silicone that smells like vinegar is acidic – Don’t use it or all your good work will be for naught. The wire will corrode.
I should note that there are situations where a crimped joint will fail. Corrosion or big differences in the expansion of the metals used are two. Aluminum wire presents both of these problems. The other is tension. A spliced connection has to have some slack in it, or the wires will probably pull out eventually.
In closing – If you’ve decided that soldering is still the way to go for your situation, do yourself a favor and Google “Lineman Splice”. At least you’ll have an electrically and mechanically sound joint to work with. The BIG drawback in soldering automotive wiring is that stranded wire must be used for its flexability. The little strands get hardened by the heat way faster than a solid wire would.
Do it right and it will last. Do it haphazardly and it will come back to bite you – Probably when you least need a problem. This seems to apply to more than just electrical connections… :frown5:
