flyingace451

Just went out and got me a soldering iron, flux, rosin core solder, and some electrical tape today in preparation for my first ARF that i get tomorrow. I decided to test it out (soldering that is) on some spare parts that could no longer be used in any of my planes. I heat up the soldering iron and as it heats up I get everything all prepped and set out. The soldering iron heats up, but it turns from it's new metal color, to a bronze like burnt color. That is my first issue. Is this supposed to happen to all new soldering irons? Moving on. Tell me if this is wrong or something. I dipped both wires in flux and tinned them both by letting solder accumulate on the tip and touching the wires to it. Now, is that the proper way to tin? Because now I have dried solder on my tip and it won't come off. Now, I held both wires together and touched the area where they touched to the iron. Solder on both remelted and I pressed them together and then let it dry. I unplugged the iron and insulated the wires with the electrical tape (I don't have any heat shrink tubing yet). The connection works because I tested it. But what about my approach to doing it, my iron's new color, and the dried up solder?

My first ARF, so I'm completely new.

jdetray

What kind of soldering iron do you have? A 25-40 watt pencil type iron is the right tool for our kind of soldering.

If you have rosin core solder designed for electronics work, separate flux is not necessary.

It is normal for the tip of the iron to discolor when it heats up.

Accumulating solder on the tip of the iron and then touching it to the wires it definitely NOT the right way to do it!

Read on ...

The Three Rules of Successful Soldering
1. Keep it clean
2. Make a good mechanical connection (where possible)
3. Heat the work, not the solder

Keep It Clean
Have a damp sponge or cloth handy, and wipe the hot tip on it before and after each and every soldering operation. Do this every time so that it becomes a habit. The result will be better, more reliable solder joints and a longer lifetime for your soldering iron tips.

Make a Good Mechanical Connection
Solder isn't really designed to hold parts together; it is designed to make a good electrical connection between them. So, whenever possible, make a good mechanical connection between the parts to be soldered before you actually solder them. For example, when soldering two wires together, twist the wires together first if you can. It's not always possible to do this, but if you can, it's a good idea.

Heat the Work, Not the Solder
Proper technique is to get the parts you are soldering (the work) hot enough that the solder will melt and flow over the parts without the soldering iron touching the solder. If you don't get the work hot enough, you can end up with a "cold" solder joint, one that is electrically poor and subject to failure. A proper solder joint will be smooth and shiny. If it is lumpy, dull, or grainy looking, it's a cold joint and may not be reliable.

Now some practical tips.

Your first step should be to tin the iron. Let the iron heat up, then apply a small amount of solder to the tip of the iron. It should melt very easily and coat the tip. Using a damp sponge or damp cloth, wipe the tip to remove excess solder, leaving a smooth, shiny coating of solder on the tip.

Find a way to hold the work very steady so the parts are held together and do not move while you are soldering them. Spring-type clothespins are useful for this. The parts (or wires) must not move while you are soldering them, or you risk cold joints.

To make a solder joint, first apply the iron to the work and let the work heat up. Keeping the iron on the work, touch the solder to the work. It should melt and flow over the work. In the case of wire, the solder should flow easily into the wire strands. If the solder does not flow when touched to the work, the work is not hot enough.

Remember: Wipe the tip on your damp sponge or cloth before and after each joint. Never let solder accumulate on the tip.

- Jeff

pilotpete2

Jeff gave you a great deal of info on soldering, the only thing I would like to address is the issue of the flux you used, as Jeff said, you do not use a separate flux in electronic work, just the rosin flux in the solder, if the paste flux you used is from the plumbimg department, it is acid flux and any work you have done will need to be redone and your soldering iron tip will need to be cleaned, acid flux will corode the copper wire completely off. If the flux you used is labeled as for electronic/electrical work, please disregard my rant
Best regards,
pete

jdetray

Good point, Pete. That acid flux is nasty stuff where any kind of electronics is concerned.

- Jeff

pilotpete2

Hi Jeff,
A few years back an older flying buddy of mine was lamenting that all the connectors that he soldered up seemed to fall apart in about 6 mos. When I asked what he was using, he replied, the same stuff I use to sweat pipes, Oatey #95 paste flux. I gave him a bunch of Kester rosin core, and he been ok since.
Best regards,
Pete

P.S. Where abouts is Napolean, I've spent a lot of time in the Dayton area, know that part of OH real well[8D]

jdetray

Hi Pete,

Napoleon is in northwest Ohio, not far from Toledo. It's a small city, but we have a nice [link=http://www.thistledownflyers.com/]R/C flying club[/link].

- Jeff

flyingace451

Wow that helps me out a ton! I guess I didn't need to buy that flux then (it was rated for electronics stuff so it didn't hurt anything) and I think I'll need a new tip as the one that came with it is extremely dirty and black after all of my improper use.[&:] When you say change color when heating, does that mean it changes back to normal afterwards? Or does it stay that color forever. If it's not supposed to stay that color, will that mean I need a new iron too?[:@] I'm glad I experimented on stuff that couldn't be used anyway. But I think I'll need to redo my ESC connector job.[:@][:@]

jdetray

Don't worry about the iron changing color. The only part that matters is the tip. Get a new tip, tin it, and keep it clean.

- Jeff

pilotpete2

Glad to hear that the flux was OK[8D], another point to consider, your new iron may be too hot, is it a 40 watt iron? if so it may be too hot for the work you are doing, if so, there is an easy fix. The best irons are the variable heat stations where the iron is usually a 40 watter, but the base unit has a variable output, so you can turn down the heat. Here's the good part, you can mount up a inexpensive light dimmer in a double outlet box with a duplex outlet, and bingo there is you're heat control. OK, Ok I know some people will be jumping up and down now as to how that dimmer is for incandecant lamp use only, translation, no fluorecent light, no motors, but a soldering iron is a pure resistive device just like a incandecent bulb and only a 40 watt one to boot. Your tip should only turn to a slightly darker color from heat, and should be wiped regularly on a damp sponge.
I should add, only attempt the heat control if you are comfortable with 120V ac household current.
Regards,
Pete

pilotpete2

Jeff,
I enjoyed visiting your field, looks real nice. Also sounds like you guys are very open to all types of models[8D] Our group is very laid back, and models of all types are appreciated. When our one 3D guru is doing his thing, no body grouses about hoggin the runway, they're more interested in watching and learning, when the same guy gets his 4 stroke SE 5a ready to go, nobody else goes up, they are too interested in his scale like handling of that plane. Here's the directions to our field
http://home.comcast.net/~trailduster/GFF.html

Best regards,
Pete