Dumb question regarding soldering

[crawdad]

Folks, in spite of the fact that I'm going to look like an idiot for asking this question, I'm going to ask anyway.
I can't seem to get my soldered wires to hold very good . I'm using a resin core solder and a 105 watt gun. When you solder wires together, do you hold the solder gun to the wire and heat the wire up and then touch the solder to the wire? Or do you just use the gun to melt the solder and let it flow onto the wire? I apologize for being ignorant about this sort of stuff, but I've always just twisted and taped in the past. Looks like I may have to go back to that unless some of you can give me a quick lesson in soldering. Thanks as usual.

[crunchbird]

I'm not a pro, but...First, clip and strip so you are soldering clean wires. You want a good mechanical connection between the two wires by twisting. Heat the wire and run the solder into the joint. If you just drip melted solder on, you might as well use wax. Soldering a wire to a connector also wants to be clean and strong as possible first.

A well-soldered joint is strong and conducts very well. You want a clean soldering tip that is "tinned" which means a layer of solder coats it. If the melted solder beads up the tip is not clean and should be sanded or wire brushed. The clean hot wire will also get smoothly coated when the solder runs in. Good joints just look like they are painted gray, without gobs of extra solder. A thin layer of a few atoms of solder between adjacent wires are doing the job mechanically and electrically.

My gun is 150W, but sometimes the tip isn't quite properly seated and then it won't get hot enough.

My dumb question: I used to have a can of an acid flux, or get flux-core solder. Is the resin core the same? I just grab something from Fred Meyer but not too sure it's the best.

[Bob Falter]

David is right, you need to have the solder gun tip tinned (coated with solder) and the solder should flow out across the tip, not bead up on the tip. It is best to tin them when they are new. If the tip has been heated several times without being tinned it get a coating on it that make it hard to tin. Try cleaning it with a wire brush but if you can’t get it to tin, pitch it and get a new one. The tip must also be tight in the gun. This is critical. You may have to tighten it each time you use it. Once you have this, get your wires ready to solder. Like David said, they need to be clean. Pull the trigger of the soldering gun and let it preheat. Touch a little solder to it. The solder should flow onto the tip and there should been some smoke. While keeping the gun on, shake, or wipe, excess solder off the tip. Touch the tip to the wire, then touch the tip with just a dab of solder. This little bit of solder will flow onto the tip and some of the wires and help the heat to be transferred to the wires. Give it a few seconds, then touch the solder to the wires. It should flow into (stranded wire) and around the wire coating it with a shiny silver color. It should not just glob onto the wire. If it does you are not getting enough heat. Resin and flux core solder are about the same thing. I wouldn’t use acid core. Hope this helps.

Bob
'79 Special

[nashville_bill]

The info you have been given is excellent. Make sure you end up with a shiny smooth coating of solder on the joint. If the solder is dull, it didn't get hot enough or the wires weren't clean enough.

Never use acid core solder on electrical connections. It will corrode!

[Jerry]

Just to confirm....hold the tip of the soldering iron to the wire joint, then place the tip of the solder on the wire, not on the gun. When the wire gets hot enough the solder will melt and flow into the wire joint.

On a side note...soldering wires does make the joint less flexible and more prone to breaking by vibration. I have taken to putting a bit of heat shrink tubing on the wire first (slide it away from the wire joint) then, when the joint is cool, siding the tubing over the joint and shrinking it down. You can use a heat gun made for this, or any heat source, such as a wooden kitchen math or propane torch. BE CAREFUL! This seems to take some of the strain off the solder joint itself and decreases the chance of a failure.

Some connections I just stake the wire to a crimp-on connector, then coat the connection with liquid electrical tape, available at most hardware or auto parts stores.

[crawdad]

Thanks very much fellas. I see several areas where I may have screwed up. I'll re-read over the post one more time and go out and give it another try. Thanks for all your help. I hope someone else can use it also.

[Jdwags]

another option

One of the sids, gave me an alternative..

they are called knife connectors.. they go on like crimp connectors, and then knife together, and with the splice shrink tubing they make a permanent connection..

I have talked to many long time car/bike guys that quit soldering the connections, as it heats the wires too much ...


I am looking for these connectiors myself..

[sixtysix]

one of the sids?

Sure it wasn't me inthis posting?

http://www.xs11.com/forum/showthread...ght=Fuse+Block

Here is what I said about knife connectors and a link to a file that shows how they work:

No actually I never use solder unless there is no other choice, it weakens the wire and makes it more prone to breakage. I use Amp knife connectors on all my wire splices, crimped with an Amp crimper these connections are gauranteed for life.

If you are really interested in these connectors here is a link to the instruction sheet that comes with the connectors. You will nee acrobat reader since it is a PDF file.

http://catalog.tycoelectronics.com/T.../21/159122.pdf

[sksxs1100]

if you are going to us heatshrink , go find "Anchor" brand marine gade heatshrink with adhesive lining. it seals the connection very well... i use the stuff every day at work and i have had no corrosion problems with wires that are submerged in water 24-7

[StanS]

Soldering

I am an electronics / computer engineer. I have spend years doing electronics assembly work. I grew up with building things outta Popular Electronics and taking all the electronics courses I could.

I know soldering. Part of what I do now still involves soldering every day.

I have also built automotive wiring harnesses and rewired cars (Porsche 356s and VWs and dune buggies).

Everyone here is correct.

When splicing wires together, first make a good mechanical connection and then solder it. Heat up the joint with the soldering iron...with a small amount of solder on it to help heat the connection. As it heats, touch the solder to the connection. When the solder starts to melt, add a bit more. The solder will (should) 'flow', that is, run along the wire(s) and not blob up.

If you use to much solder, hit or jar the joint and excess solder will splash off. (Hit it away from you...)

Rosin core and acid core solder are NOT the same. Only use rosin core for electrical work. The acid will eventually eat the wires.

When working on bikes (and cars) keep in mind that Yamaha does not solder ANY of the connections on these bikes. You also won't find soldered connections in any car. They use those damned connectors for a reason. It makes building it and servicing easier. When done properly they're more reliable than soldered connections.

If I have a bad wire, before I splice it I look to see what it takes to replace it (and then I splice it (maybe)).

Stan
XS1100LG '80 Midnight Special

[crawdad]

I'm glad I asked the question now. Got more than my moneys worth with this one. Good stuff to know. Thank you all very much.