Soldering

[Sandra]

Soldering so far seems to be my weak point! Today I soldered a couple pieces of metal together using medium strip solder and it turned out ok, though I see I missed an area. I have a bit of a problem keeping those little silver solder pieces from flying away!

My next pieces to solder on the same piece I used an easy silver solder paste. After three times of soldering and ending up with a very weak join that broke with the slightest resistance I've quit for the night. I've never used solder paste before and not quite sure what to make of it. Is it supposed to get the liquid look the same as solder strip? It never really seemed to and I had it under fire for what seemed too long. Tomorrow I am going to put a blob of solder paste on a scrap piece of metal uncovered and hit it with a torch to see how it reacts and how long it takes.

Are there other options for soldering delicate areas that are appropriate such as a soldering iron maybe?

[caroleallen]

As long as your join is good, you should find that paste solder works in the same way and you get the same "flash". I only use it when I'm soldering something onto something else like a gold heart onto a ring where it's difficult to use a pallion. I also use it when soldering small things like jump rings. It's just as strong as strip solder.

[Sandra]

What could I be doing wrong that my joins aren't holding? Is it possible I am overheating it? I figured too much heat must be better than not enough but maybe not. And then I'm never quite sure what the best way to clean the metal prior to soldering. I've tried sanding with fine paper, pickled, used mineral spirits, sometimes washing up liquid but haven't decided what actually works. Maybe there was a residue on the metal?

[caroleallen]

Maybe you're trying too hard. As long as you have 2 closely fitting pieces (hold the join up to the light and if you can see daylight through the gap, you need to resaw the join) you only really have to give the pieces a quick rub with a bit of wet and dry (I don't normally bother) and they're ready to solder. I never do anything to actually wash the pieces, it's just not necessary.

When you heat the piece, do you make sure the whole piece is hot before you direct the flame onto the join?

[Dennis]

Hi Sandra, At the moment you seem to be stuck, but as Carole has said there is no need to wash anything. The pieces to be joined need to be freshly cut, or filed, or rubbed up with an abrasive pad, or a retractable glass brush, so that they are bright.

That said, traces of pickle tend to inhibit soldering, so that needs to be rinsed away thoroughly.

Beginners are attracted to solder paste, partly because it has its own flux and seems easy to use. In fact I find it extremely tricky and have often been let down by it. It is particularly prone to burn to a cinder instead of flowing, if the soldering flame hits it before the whole piece is upto temperature.

As for medium strip solder, most of us shun it as an invention of the devil, because it tends to trickle instead of flowing. That leaves hard and easy solder strip and in some circumstances extra easy.

Then there is solder flying off which is a matter of applying the heat very gently at first, until the borax has expanded (flowered) and collapsed again. I you find yourself impatient with this, you can recruit a hairdryer to do this part for you. Actually a number of us use Auflux/Auroflux, which comes as a liquid and is less prone to swell up.

Please note the the same grade can be used more than once consecutively, because it will only re-melt next at a higher temperature.

Soft solder (and soldering irons) can be used for non precious metals, but is not of hallmarking quality, and traces of it can contaminate a bench and your tools, making it a no no near precious metals.

Please keep asking until you succeed. Dennis.

[Sandra]

Oh thanks to both of you, I know what I am doing wrong now! I am definitely getting too anxious and hitting the piece with a direct fame too quickly. I also used pickle prior to soldering the last few times.
I chose medium solder at the time because I wasn't sure which to order so thought the middle one was safest. I really do not like the solder paste though. My next purchase is going to have to be easy solder strips and borax. I'm trying my hardest to finish a piece for the October competition but am still learning as I go along so it's slow going!

[CJ57]

Oh thanks to both of you, I know what I am doing wrong now! I am definitely getting too anxious and hitting the piece with a direct fame too quickly. I also used pickle prior to soldering the last few times.
I chose medium solder at the time because I wasn't sure which to order so thought the middle one was safest. I really do not like the solder paste though. My next purchase is going to have to be easy solder strips and borax. I'm trying my hardest to finish a piece for the October competition but am still learning as I go along so it's slow going!

Hi Sandra
If you have to solder more than once I would start with hard solder and then use easy for your second. As Dennis has already said warm up your whole piece to get your flux to either bubble or settle down, if you don't heat it too hard then your solder pallions should stay in place, if they pop off, then just move your torch away and put them back in place. The other option is to warm your piece, then add your pallions which I also brush with auflux, that way the flux sort of binds the pallions to where you want them to be. I would say that the cleaning and detergent will be adding a skin when you really want to be giving a light rub with emery to make sure everything is clean and a good surface to solder together. Once you get the hang of it you might even enjoy it

[mizgeorge]

I love paste - and because I have to work quickly because of the sheer volume of stuff I produce, I use it almost exclusively now. Heat the metal, not the solder, and don't be afraid to get things really hot. My prep for soldering consists of cutting, filing if necessary and no more, other than trying not to get too many oily fingerprints on the metal. I can't remember the last time I used medium solder of any type, though, as like Dennis, I loathe the stuff.

I'd always recommend having a bit of a play with deliberately melting some bits of metal so you can get a real feel for just how far you can go before it will melt, and to see what happens just beforehand.

[caroleallen]

It also depends on what you're soldering and what sort of torch you're using.

[Goldsmith]

The others have mostly covered your questions with good ideas. I agree with them that medium silver solder is not great. I manage with just hard and easy.
Let me say how I solder. I use a borax cone and borax plate for flux. I have a scraper which is used to clean the solder strips before cutting off pallions, a lot of people clean the solder joint but never think to clean the solder.
Now for soldering, I file each surface clean then apply borax with a paint brush to each surface before closing and securing the solder joint shut. Then I gently heat the item so that the borax bubbles and sets, then I pick up the cut solder pallion (square) with tweezers and dip it into the liquid borax, then when I hold it on the heated solder join it sizzles and sticks where I want it. Then gently heat the whole item bringing te whole item's heat up to near the solder running temperature, only then will I concentrate the heat on the solder join, remember that the solder will run towards the hottest point, so for instance when soldering a ring joint, heat from the opposite side to where the solder piece is attached, a fierce flame is not needed for silver soldering.
I was always taught that the method of good soldering is to heat the solder area on the metal up to the melting point of the solder, rather than just trying to melt the solder.
Sorry to go on but something like soldering is hard to explain in words, it is something that needs to be demonstrated.

James