I'm trying to solder something, and for some reason it doesn't seem to be working.
If i put a strip of metal across the points without solder, it works. The circuit is fine.

Soldered? Nothing. Intermittent connection at best.

What am i doing wrong? I've tried to finish the circuit with a foil strip (that worked), a copper strip is intermittent.

Help!

An intermittent fault elsewhere or rubbish soldering. Must be.

When you say 'something'. Is it something that is meant to be soldered?
Could just be that the flux you have isn't active enough for the base metal you're trying to solder.

I think you may need to accept that your soldering may be rubbish. Strip all the joints clean with solder mop or a solder sucker and start all over again with fresh solder and flux?

If that doesn't do it then without seeing it I've no idea what will.

I'm sorry your vibrator is broken:(

Admittedly it's a first attempt at soldering so it could easily be that. It has been soldered before so yes I think it's meant to be soldered. i didn't think it was an intermittent fault before as without solder it was fine.

Ian – could you explain in idiot terms what you mean by flux etc?

You're not trying to fix it yourself are you?! Send the thing back!

Too late now, he's butchered it.

Most solder will have flux in it already, should say on the label.

If possible, forget the metal strip and just use a small bit of electrical wire. Put wire on contact, hold down with tip of iron, then after a few seconds, touch the contact with the solder. If it doesn't melt instantly, remove and continue heating. When the correct temp is reached, the solder will flow across everything…remove iron but don't move the wire at all. If the solder is a smooth shiny dome its good, if it looks dulled or has balled up, its a dry joint and needs redoing. Its important to heat both wire and contact so they are both hot otherwise the solder won't flow.

You'll probably find that the metal strip is conducting too much heat away from the contact and iron isn't powerful enough to get everything hot enough.

I'm sorry your vibrator is broken:(

What did you do to break his vibrator?!

Sounds like the flux isn't coping with the surface to me. If you'd tell us more about what you're soldering it might help 🙂 Or you're using a piffling iron on a large contact volume.

If the solder is a smooth shiny dome its good

Solder shouldn't be a dome, it should be a nice slightly concaved cone, dome's are too much solder (and possibly other problems)!
Good:

bad:

I don't know what he's soldering…a flat contact on a PCB would have a raised dome of solder would it not? Not a big blob, just a slight bump.

Edit: your pics just loaded, I see what you mean now by concave cone. I was thinking of a wire laid across a pad rather than inserted through the PCB from the reverse side, leaving the lead sticking out of the solder.

Flux is a concoction of chemicals that aids the solder sticking to the metal. Normally it's built into solder designed for soldering electronics together, but generally not if the solder has come from the plumbing section of B&Q. In which case you'll need some external flux (available from the same place)
Does the joint you've made look nice and shiny with a smooth join exactly like these?

/edit Coffeking's beaten me to it 🙂

What did you do to break his vibrator?!

after where it's been you expect me to touch it ??

I can't think of an example of a domed solder joint, it's being pedantic as it could be a perfectly usable joint, but it's too much solder to me. Even the most heaped up, 3 wires twisted together and soldered flat onto a rectangular pad will come up with concave sides if you don't flood it.

after where it's been you expect me to touch it ??

No, well, no again anyway. 🙂

it's a contact strip to a circuit board from a cell

Try gently sanding the strip and then cleaning it…probably dirty so the solder won't stick.

Coffeeking…yeah I think we are agreeing but I just didn't describe very well… B on top line.

Yup, we were arguing the same point 🙂 I spent 3 hours last week going over and over and over soldering technique with students who still couldn't manage to get an LM298 onto a board without 50% dry joints. Maybe I'm in the wrong job!

I used to sit and watch my dad soldering for hours as a kid – I thought he was some kind of god for being able to do it so well, so neatly, so deftly.

I recall (this was some 35 years ago) he would first ensure everything was clean then heat the terminal wire with the gun then 'wipe' the solder on and down onto the circuit board. He would always keep direct heat well away from the circuit board as they are very delicate. The gun was always free from solder when he started a join – the solder only going on when the terminal wire was heated.

I loved the smell 🙂

Tip needs to be tinned slightly to get heat transfer (or you'll sit for hours with the tip on the lead) but needs to be kept nice and clean between joins. I tend to direct heat the pads but only if they're a large pad and not for very long (you don't want them to lift!) but sometimes it is possible to use the wire to transfer heat to the pad. Either way it's not too important, you just need to get the pad up to temp or you'll get the solder floating on the pad and not connecting. My usual technique is to contact the wire with the iron, about 3mm up from the pad, slide it down to the pad and feed in the solder (against the wire, at the pad/wire join, not the tip) at the same time in one smooth move. The wire usually takes longer to heat than the pad so that gives the wire time to heat up, then means I hit the pad/wire join with the solder just as the pad has reached optimum temp. Works for me anyway 🙂

Forgot to mention the lead-free solder is cosiderably harder to solder properly, in my experience. Not impossible by any stretch, but more difficult to get right.

coffeeking – that sounds like a clear first hand description of what I ham-fistedly tried to describe based on dim recollections 🙂

and just like what i was ham-fistedly doing last night.