I have been practicing soldering on a few scrap boards, etc, before I start moving onto real boards.

I have a small 25 watt iron which I have been using. I saw a small tutorial on joining a stranded-copper wire in which you were suppose to heat the copper from underneath (with the iron) and then with enough heat put the solder on top and it should let it flow around the join of the copper.

I did this, but after finding myself holding the iron under for at least 2 minutes or so, the copper didn’t get hot enough to melt the solder. I also find when soldering on boards it takes me at least 10 seconds to heat up the components enough to let the solder melt.

Would this be a problem of a poor Iron (Dick Smith branded 25watt Iron)? Or poor solder (Dick Smith Super Solder – 60/40% – 0.56mm)? Or just me doing something wrong?

I should also note that the solder says nothing about Flux on it, however I wouldn’t think this is the problem because I can’t even get the solder to melt without holding the iron there for long amounts of time. And when on boards, after I solder there is a browny-type burn speckled around the joints I have soldered.

Thanks for your time :)

I’ve never used the Dick Smith brand of soldering equipment so I don’t know whether it performs as bad as the name sounds or not. 25 Watts should be fine for tinning / joining small wires and connecting typical components to PC boards. 60/40 and .56mm diameter are also fine. I’ll bet that the solder contains a flux core unless it says “solid” on the label. This type of solder is rare compared to standard flux-cored solder, so you’d be pretty unlucky to have it.

My first piece of advice is to be sure your iron tip is thoroughly tinned before placing it against the wire or circuit board. Very little heat will transfer through a “dry” tip. Some solder is needed to form a heat bridge of sorts between the tip and component or wire. Try getting a blob of solder between the tip and wire. Does solder melt quickly and easily onto the tip? If not, chances are that the tip is oxidized and requires cleaning. Repeatedly wipe it against a wet sponge and apply solder until solder easily clings to and spreads over the tip. The flux in the solder will help to clean it. Always keep a coating of solder on the tip to prevent / slow down oxidation.

Rosin flux residues can look yellow / brownish and still be OK. For instance:

the “charred flux residue” isn’t that uncommon to see or problematic. If the board itself looks charred, that’s not good. The whole soldering operation should take no more than 5 seconds for typical through-hole components. Joining larger wires may take more time.

It could be that the iron is actually a piece of junk (or at least has an oxidized tip). If you just need to solder a few circuits and want to try a different iron, I’d recommend getting a 25 Watt iron from RadioShack®. I think they’re only $10 or so and I know they’ll get the job done, at least when brand new. If you’re going to be doing a decent amount of soldering and want something that’ll last, we sell a 25 Watt Weller iron that will last longer and is easier and more comfortable to use.

Let me know if this advice helps you out, or if you figure something else out, I’m sure others would like to know.