Sunday, April 26, 2009

Solder Basics 101

I started writing this Sunday but didn't finish and I've had food poisoning since Monday or this would have been up way sooner.

Okayyyy. Back to the topic of this blog! Last time I wrote anything metals related, I was talking about soldering. I'd like to cover a few more things I've learned over the years, which doesn't mean I don't still screw things up, but knowing a few tricks goes a looong way to minimizing the screw-ups. Plus, I haven't yet created a solder god for my solder-station so I'm flying solo right now!

So, for starters, and forgive me if I repeat info from a previous post, the metal must be clean (no oxidation or oils) and the areas to solder must make physical contact. No gaps. Silver solder does not fill in gaps! I like to hold the join area up to a light source to look for any light coming through. If light comes through, I need to sand or file one of the two pieces to make a tighter fit. If you know one piece is the way you want it, always try to work the other one only to create the fit. Keep one piece constant so you have less variables to deal with. To clean a piece, you can sand the surface or throw it in the pickle (keep your pickle hot and strong and only leave work in briefly). You could remove hand oils and such with soap but if there's oxidation, soap won't help.

As I mentioned before, I like to sweat solder as much as humanly possible. So what is sweat solder? Some people refer to it as "tinning" (sp?), where you cover the area to be connected of one piece with solder (always cover the smaller piece), flow the solder, then place the solder covered piece on the piece you want to connect it to and re-flow the solder, joining the two pieces. The most important thing to remember is to heat the non-solder covered piece up more than the solder-covered piece to facilitate the transfer of solder from one piece to the other. I usually make this a 2 step process but you can do it in one.

With that said, let's go through an actual example.

So here's my set up. I always use a solder pan so I can rotate the work as needed and I solder on an old fashioned kiln brick. When the brick gets dirty, I just take it out to the concrete and sand it smooth and clean. Great stuff.

Here is one of the pieces I'll use for my example. This is another one of the Primal Scream pins. The surface is sanded and I'm ready to solder. The smaller items to the right are my name stamp plate, the backs of the bezel cups and the pin findings, all with a little solder already flown. The stamp plate has hard, pin findings have medium and the bezel cups have easy.

Here is the piece fluxed and with the stamp plate on top.

I want to heat the sheet and not the stamp plate until the flux goes clear and I can tell the larger piece is at soldering temperature. Then I brush the flame over the stamp plate and watch for a mercury-like seam of solder to appear between the two pieces of metal.

FYI- always make sure your solder brick is as level as humanly possible. Gravity is not your friend when soldering. Also, use just the haziest coating of flux possible. I've seen pieces slide and solder way off where you'd want them when there's too much flux and the brick isn't level.

I pickled the piece and refluxed and added the pin findings. Again, I'm just going to heat the large sheet until it gets up to soldering temperature then I'll let the flame hit the pin findings.
Once the back is done, it's time to solder the bezel cups.

I coat the back solder area with yellow ochre because I'm going to have to flip the piece over and- gravity is not my friend :-)
Speaking of gravity, now that the pin findings are soldered to the back, I no longer have a level surface to solder my bezel cups to. I don't want to hang the pin findings off the side of the brick because- gravity is not my friend! So I need a way to level out the piece so my bezel cups will stay where I put them and solder nicely. Any old non-flammable, not likely to solder to the piece, not likely to off gas toxic fumes when heated object will do and I just happened to have an old piece of binding wire lying around and the height was right so that's what I used.

Once I'm done soldering I transfer my pieces to a clean steel block so they'll cool fast before pickling. I don't quench anything and I especially don't quench silver and you should never throw hot metal into pickle of course. The steel block works great because it acts as a heat sink and sucks the heat out of my pieces lickety split.

To quench or not to quench and 101 uses for binding wire will have to wait for another time. Hope this was helpful!

1 comment: