Is rosin core solder good. I'm trying to solder some wire to a new deans connector but the solder will not stick, i keep getting an oily like film on the connector. Any ideas?

also does anyone live close to south march that can charge 2 batteries for me, a 11v15c li-po and a 1400mha Ni-Mh ?

Thanks

To get solder to stick you need to get both materials to the same temperature as the molten solder. If your soldering iron doesn't go that hot you may need to hold it to the surface, with some solder between, for several seconds up to a minute for really cheap ones.

Rosin core solder is all I use. Just make sure it contains lead and not just tin; the lead is much better (usually 20-40% lead, the rest tin) as its easier to use and produces a stronger bond. Pure tin can work but isn't as good (like most non-toxic things that replace old toxic things.) Rosin core means it contains a core of flux which aids the solder in sticking to a surface. The flux decreases the temperature needed for the solder to stick to other metals. The "oily" film is the flux melting out of the solder and sticking to the metal. If you heat it a little more the solder will then flow over the flux and stick to the metal as well.

If the solder just falls off or comes off with a flick after solidifying then I'd say 99% chance you didn't heat up the material it was sticking to enough. To make it a lot easier you "wet" both sides (such as the wire and the connector) with solder which means you coat them individually. Then it takes much less time to stick the two together as opposed to trying to combine the three parts (wire, connector, and solder) at the same time.

Is it a "gun" type soldering iron? I hate those and find them very difficult to use compared to a regular pencil type soldering iron.

When the surface is too cold the solder beads up on the surface like water on wax paper. Once its hot enough the solder spreads out almost like its soaking into the metal. When the wire is heated sufficiently the solder flows between the strands and literally gets soaked into the fibres.

A really hot soldering iron (700-900'F) will heat up the base metal quickly in the area being soldered before it spreads through the entire piece. If you use a cheap, cooler, soldering iron it will heat up slowly which can cause the connector to melt in the plastic housing of the deans plug which can warp it and the prongs on either side wont line up properly after that. Pure tin solder also requires a higher temperature for its weaker bond which can cause problems as well with warping. It seems counter-intuitive but a hotter soldering iron means less melting in the surrounding area.

so it's my soldering pen not the solder. I'm use a cold heat soldering iron with is a pain at the best of time and the solder i have is 60/40 Tin/lead and 1mm thick

I have never used the cold heat soldering pens so I looked it up:
http://science.howstuffworks.com/cold-heat2.htm

It uses the resistance of the solder itself so only heats the solder. If you where soldering on something very thin like a single strand wire, thin copper circuit board connectors, or something else with VERY little thermal mass it would work. But when soldering on thicker metals like airsoft gauge wire (14-18 gauge) and the large solid tabs on deans plugs, a "Cold Heat" soldering tool wont work.

You could try leaving it stuck to the solder longer to try to heat the underlying metal but with only some AA batteries it will probably take quite a while to heat.

I would find someone with a real soldering iron. The proper tools for a job always makes things a lot easier. I would offer to help but I live no where near March road

Thanks for you help LUTNIT, i got 12 gauge deans wire that i was going to use to scab on to the old connecting so i wouldn't have to open the mech box and rewire it right from the trigger switch, will it be fine or is it going to be a problem?

A lot of people will say splicing wires is really bad and adds a lot of resistance. I tested a bunch of wires purposely botching the splices to try to get high resistance; never happened. I used a cheap Canadian Tire volt metre but I couldn't get it to register even 0.1 ohm resistance.

Spliced wires do have a bulge and are stiffer in that section but aren't really an issue electrically. It really should be soldered though it will work if it isn't (I have received used guns in this condition )

(11-13-2011 12:39 AM)LUTNIT Wrote:  A lot of people will say splicing wires is really bad and adds a lot of resistance. I tested a bunch of wires purposely botching the splices to try to get high resistance; never happened. I used a cheap Canadian Tire volt metre but I couldn't get it to register even 0.1 ohm resistance.

Spliced wires do have a bulge and are stiffer in that section but aren't really an issue electrically. It really should be soldered though it will work if it isn't (I have received used guns in this condition )

From my experience:

I damaged in some wires in my mechbox and it caused the fuse to keep blowing, and eventually also caused the wiring to fail elsewhere.

Spliced/damaged wiring tends to increase resistance the more current you flow through it, in my experience. You may not notice it with a multimeter, but flow current through it, and you'll see the result.

I solder with silver solder, that I've got left over from electronics I used to do back in university. It's harder to solder with because there's no rosin built in, but I find it's less messy and easier to control. I own both a 25/45w soldering station and a cold-heat iron. Each iron has it's place. I like the cold heat for small wiring work, or work where I can't afford to get a hot iron in there, and I just want to heat the wire, whereas the full size iron is great for deans tabs and tinning.

I've run spliced wires in nearly all my AEG's where I remove the fuse. I have noticed no difference between spiced wires and rewiring the gun completely with quality wire of the same gauge. The amperage draw is the same and as such the battery life is pretty much the same. Voltage is based on the battery itself so no change there either.

Damaging wire inside a mechbox is totally different. It just causes the whole system to try to draw more and more amperage which blows the fuse. Spliced wires with good heat shrink over it doesn't do much.