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Do you twist them together and then solder them or do you put solder on each wire end and then melt them together?
 

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Twist them together first before soldering is the correct method. You want the joint to be linear in the direction of the wire. What I mean by that is you should be able to slide a piece of heat shrink over your joint. The joint should not be 90 degrees to the wire. Strip about an inch from both ends. Hold them against each other and use a twisting motion grasping one wire in one hand and the other wire in the other hand and twist opposite of each hand. Cover the joint with the proper sized heat shrink tubing.

Vince
 

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Bullet Proof wire connections

Here's how I was taught to make soldered wire joints that absolutely will not come apart:
1. Strip 1/2" of wire.
2. Slip correct size heat shrink tubing over one wire. I use two sections of tubing. One's length is cut to fit between the insulation of both wires, the other is cut to overlap at least 1/2" of the insulation of both wires. You can use tape but tape ALWAYS comes loose eventually.
3. Overlap wire ends.
4. Using one strand of copper wire pulled from 12-16AWG wire, wrap the overlapped ends so the strands are secured. (think of the appearance of the knot on a hangman's noose)
5. Solder the joint.
6. Dress down excess solder and ends of wire wrapping to make smooth surface and fit shrink tubing.

This method results in a joint that is short, trim, and will not make an ugly bulge in the harness.

BTW, I also solder crimp-on connectors instead of crimping them. The insulation can be pushed off the connector for soldering and pushed back. Lots of extra work? Yes. Worth the effort? Definitely!

My thanks to Alex Davies, formerly of the X-Garage for this tip.
 

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My joint

My interpretation is to strip off some one inch of insulation off the wire, fan out the strands of the terminated wire, fan out the strands of the wire interleave the strands onto the which is to be tapped onto, twist together & solder.
_________________________________________________Rick....
 

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soldering wires

There is a type of solder made for electrical work. It is called rosin core, it doesn't corrode the connection. It is usually thinner than other roll solder so you don't transfer as much heat to your work. It is important to not move the soldered connection until the solder hardens, else the molten solder crystallizes and you have a bad connection.
 

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Doc here, :pimp:

Mine is similar to Mike's..

For most small jobs, use a 40 watt Controlled station OR pencil Iron.

About a pound of 24 Ga , 60/40 Rosin Core solder.

Strip Each wire Approx, 1 1/2 inches back.

Slide Shrink tube (approx 3 inches) over the wire, and another approx 1/4 inch smaller , and different color, with the black tubing. Twist the ends around the center of the wire at about 1 1/2 inches of the bare wire, one clockwise, one Counter Clockwise.. Trim ends.

Give the wire the "Tug" test for good mechanical fit.

Heat your wire and Solder From the Center out ALL at the same time, until the solder flows, and "Wick it toward the ends of the wires.

Your joint should be Clean smooth and SILVER, not gray, (gray is a "cold joint", if you get this cut out the section and start over.) Trim excess Whiskers.

Slide the shrink over the joint and heat to fit. Slide the second over the first and shrink. If you use a different color tubing on the second you can use it for "color coding" ) Black/Red tubing = 12 volt ect...

IF you use 60/40 Rosin core Solder, there should be no need for added Rosin on MOST small jobs.

Doc :pimp:
 

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use acid core solder in an automotive application, and you will be back to square 1 in months. make shure you got rosin core.
 

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I have tried all of them and I found the BEST joint is those that are striped, pushed together and then twisted together then soldered. As with any electrical splice you should use heat shrink tubing, so remember to add this first before putting the wires together.
 

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Your joint should be Clean smooth and SILVER, not gray, (gray is a "cold joint", if you get this cut out the section and start over.) Trim excess Whiskers.
You should not have whiskers to begin with. I was certified in aerospace soldering. Use a good wire stripper, sharp wire cutters, and cut thru just the insulation. For most wiring on cars, get a set or two of GOOD small wire cutters. A large pair of cutters like the type used to cut home electrical wiring is too large to do a proper job on smaller wires. The large type will crush and possibly not cut all of the way thru stranded wire like they do solid core wire. Believe it or not, there is an art to stripping, cutting, and soldering wires. When I went thru certification, it was unbelievable the number of people that could not pass the "cert test".
Do not "pop off" the insulation, but use your other hand to control the stripper. Break thru the insulation and let it pull away a small amount. Using a clockwise motion, "screw" the insulation off of the wire. For one, this will keep hand contaminants off of the wire, and it allows you to twist the wire tighter. Use a good resin core solder, or get a can of resin core flux. Put your iron under the wire and apply the solder to the top. The flux will heat up and the solder will flow wherever it is at. Do not bend the joint afterwards. Cover with the correct size of shrink tubing. If soldering in between two connections, make sure the shrink tube is slid onto the wire first. Also whenever you strip a wire, if you do not use the correct size of gage stripper and you use a smaller than appropriate size, you will cut the strands and when you do, you are also cutting away the pathway for electricity to flow. And always make sure that you use the proper gage of wire for the proper electrical connection. Too large or too small can be a potential fire hazard. Too small of a gage can have an effect on performance if used in an ignition type of application. Too much current flowing thru too small of a wire is the greatest risk for fire. Use fuses where applicable. They put fuse blocks in cars for reasons. And never ever just twist two wires together and cover with electrical tape. That is just asking for a problem.

Kevin
 

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302/Z28 said:
IMO the best strippers and cutters for automotive wire are made by Kline.

Vince
I always just score the insolation with my knife and try not to go so deep that I cut the wire then twist it off and twist the wire at the same time.
 
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