

| Subject: | Re: Soldered Connections...Not! |
| From: | Karl Batzler |
| Date: | Sun, 31 Jan 1999 18:43:52 -0800 |
Bill said: >So where do you get copper crimp on connectors? I think the only ones I've >ever seen for sale are aluminum (?). And many that came stock on vehicles >appear to be aluminum. But they don't seem to corrode. >Bill That's because the copper crimp connectors are generally coated with nickel or zinc to prevent corrosion. Karl Batzler 84 Vanagon 87 Audi 5000 S La Quinta, CA -----Original Message----- From: Davidson <wdavidson@THEGRID.NET> To: vanagon@GERRY.VANAGON.COM <vanagon@GERRY.VANAGON.COM> Date: Sunday, January 31, 1999 10:02 AM Subject: Re: Soldered Connections...Not! >So where do you get copper crimp on connectors? I think the only ones I've >ever seen for sale are aluminum (?). And many that came stock on vehicles >appear to be aluminum. But they don't seem to corrode. >Bill >90 Westy Syncro >-----Original Message----- >From: Carl Turner <CarlMarin@AOL.COM> >To: vanagon@GERRY.VANAGON.COM <vanagon@GERRY.VANAGON.COM> >Date: Sunday, January 31, 1999 9:43 AM >Subject: Re: Soldered Connections...Not! > > >>David Writes: >><<<<<<< >>Subject:Soldered Connections >>I think you are missing the point with soldering - or you have never seen >>it done correctly. Your examples of failing solders are not from a wire to >>wire connection but a wire to a component / circuit board connection. If >>you are soldering two wires together you must do what is called a "western >>union" connection first. This is where you strip the wires say 1.5 to >>2.0cm and put them parallel to each other so the cut end of one wire is >>next to the begining of the plastic covering of the other. Then twist the >>wires so they make a mechanical connection first. The wires should be able >>to hold together without solder. The next step is to do a propper >>soldering job where you heat the wire and not the solder thus advoiding a >>cold solder. Use decent solder that contains a very small amount of flux. >>I use the Radio Shack stuff. After you make this connection I will bet >>anyone one hundred bucks that it will NOT break. If you waterproof it with >>lithium greese and seal it with very snug heat shrink it is almost as good >>as an uncut wire - just a little stiffer where the connection is made. >> >>Crimps do have their place and work well when done with the right tools. >>They do tend to leave some part of the connection open to the atmosphere >>which makes it prone to rust and eventually failure. >><<<<<<<<< >> >>I'm afraid you'd loose that 100 dollars David! Soldered connections used >on >>equipment subject to vibration, cars, airplanes, rockets are especially >prone >>to fatique failure. The type of soldered joints used on connectors and >>splices in the mil-spec environment are highly speciallized and the specs >for >>how these wires are then harnessed and strain relieved are very specific. >The >>wiring on our Vanagons doesn't even come close to this standard. Most >wiring >>on General Aviation aircraft and most experimental homebuilt aircraft (as >Ken >>W. alluded to) is done with proper solderless crimp connections. >> >>A proper solderless crimp connection fits a proper size crimp fitting to >the >>gage wire, is compatible in material, ie copper on copper wire, aluminum on >>aluminum wire and so on. The joint is then "sealed" as it were with a >>generous length of shrink wrap that not only keeps out corrosive >environment >>but also serves to strain relieve the joint. One problem common to us all >I'm >>sure is working with the crappy crimp connectors they sell down at the >local >>flaps. They usually have some plastic cover with huge water catching cups >on >>the ends. I never really figured out what the point of those were. I >often >>just cut the plastic cover on these type of crimps off, slide one or two >>lengths of shrink wrap on the wire before crimping, do the crimp thing, >slide >>the heat shrink over the joint and warm it up ( proper heat gun, not a hair >>drier or a match please!) Resulting joints stay dry, and maintain the >>ductility of the base wire and should not corrode if you used the proper >>material crimp (remember dissimilar metals corrosion?) If the wire you are >>connecting is grubby, it should be cleaned with some scotchbrite before >>crimping. Really, the key to neat and tidy crimp connections is using >shrink >>wrap over top of them. Those blue and yellow plastic covered things they >sell >>at the auto parts store do not make for neat connections unless modified as >I >>described above . >> >>Now to the problems with soldering. Soldering can be used to solve >connection >>problems certainly. For example, you can't get a good fit for a crimp >>connection or you are joining wires of different gage or you can't get the >the >>store to buy the right crimp connections (I've been there, believe me!). >So >>what you want to do is try and create a solid mechanical connection before >you >>solder by twisting the wires together or whatever (or dare I say...use a >crimp >>sleeve) You then want to use a minumum amount of solder, not so much that >you >>coat the joint with a shiny blob of metal (I know, it looks good but its a >bad >>idea). What happens is the multistranded wire wicks the solder up along >the >>length of wire well away from the joint making that length of wire very >>brittle and prone to fatigue failure. The flux gets wicked up even further >>into the wire where it can have a corrosive effect over time (even rosen >>flux). Just take a bit of wire scrap and solder a really big blob of >solder >>to the end and really burn that baby in. When cool you'll be able to >actually >>feel how the wire has been stiffened under the insulation where the solder >>wicked up. So if solder you must, practice on some scraps till you can get >>the 1/4 inch at the end soldered but can still flex the wire beyond the >>soldered bit. You're on the right track now for an acceptable soldered >>connection. The joint should now be shrink wrapped, maybe a couple of >layers, >>each a little longer than the one underneath, to give a nice strain relief >to >>the wire. The wire should now be strain relieved with proper clamp in the >>installation so it isn't buzzing as you roll down the road or fly through >the >>wild blue yonder (depending on your personal conveyance of choice). As >>further argument in favor of my assertion, notice that all automotive >wiring >>used multistranded wire rather than single solid wire conductors. This is >for >>flexiblility and thus longer fatique life. By soldering your multistranded >>wire and binding up the strands for a significant length you are creating >>something that looks like solid single conductor wire. Anybody wiring >their >>cars with Romex? >> >>Carl Turner >>
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