The art of making a good rounded solder bead takes a lot of time and a lot of practice. It's not developed over night, but over time, and it might take a while to get the hang of it. The sign of a professional stained glass artist: the solder bead is well formed, rounded, and smooth. A well formed solder bead is not really necessary, however, it does increase the overall strength of the project. A flat on both sides can imply incompetence and laziness of the artist.
Personally, I make a solder a bead on one side of window, unless both sides are showing.
I don't like wasting solder, and I also find it takes longer to solder a bead on the back if the front is beaded, the bead on the front acts like a heat sink for the solder on the back. So all my panels are beaded on one side only. Boxes (the lids), sun catchers, and small things are beaded on both sides.
What does a good solder bead look like?
A good bead is round in shape. Worm like if you will. The joints flow together smoothly (or at least fairly smoothly). It's difficult to achieve a perfect bead, and there really isn't any one standard. My beads are fairly smooth, and I'm constantly trying to improve it's quality. But it may never be perfect. The bead shouldn't be splattered anywhere, there shouldn't be any pits, lumps, dry spots, and of course no heat cracks in the glass.
Do I need special equipment to make a nice solder bead?
Yes and No. This is what I have and use:
SOLDERING IRON: There are so many soldering irons to choose from. They range in wattage, weight, tip angle, heater type, and tip type.
Here's a list of all the tips that they sell, that I know of:
RHEOSTAT: A rheostat is a device that you plug your soldering iron into. It's a dimmer switch designed for soldering irons. It regulates the heat the tip will produce. I use it all the time, though I usually keep it on full. There may be times during the project that I may turn it down a little. It's lowered when the solder is dripping through the seams too much, or if I want to add decorative soldering. If your iron is too hot, then you need a rheostat. It's a good idea to have one in your tool box regardless. A rheostat is not used on some Weller irons, due to the special tip design.
Solder melts on the tip of the iron and starts flowing. But in order to draw a good bead, the iron has to do several things: it needs to melt the incoming solder, keep the the solder it just laid out hot, and heat up the area that's going to be soldered. So the iron needs to stay hot this whole time. The higher the wattage the better the bead. But if the wattage is too high, there may be too much heat, which is also bad. Too much heat means the solder will puddle and soak through the joint. Too little heat means that solder won't round over properly, and it will be lumpy or sharp. It can also mean that the solder didn't "soak" into the joint, which will mean structural failures in the future.
SOLDER: There are many brands of solder to choose from. Canfield, Dutchboy, Willard, to name a few. Canfield has some of the best solder you can buy, though it is more expensive then the others. Canfield's 50/50 is as soft as 60/40 compared to other brands. Or at least that's what some people say. I have used it before, and it is a good solder. Just make sure its virgin solder (designed for solder and not melted down from something else).
When you visit a stained glass store, you'll find that there are quite a few types of solder to choose from. A side note, a stained glass store isn't the only place you can buy solder at. Solder can be bought at a hardware or plumbing store. However, the solder they sell is 95/5, which isn't designed for stained glass use. If your lucky, they might have some old stock of 50/50 or 60/40 (but, both are illegal to use in the plumbing industry due to the lead concerns).
FLUX: I use liquid flux from Canfield. Gel fluxes tends to boil, and tends to suck up the heat, not to mention the smoke screen it makes. Paste flux makes a real mess; it spreads out over the glass and is really difficult to remove. However it is a good oxide inhibitor, you can spread it over the seams and leave it for months, and it will still be good the next time you want to solder again. Be sure to put it in a plastic bag or container, as this flux is sticky, and dust will stick to it. Liquid flux evaporates quickly (once heat is applied). However it tends to be fairly irritating to the skin, eyes, etc. Proper ventilation is a must. Wear gloves, a mask of some kind to slow down the mist (a respirator is best though difficult to breathe through), and an apron. Use an exhaust fan, and open a window - for all soldering.
A good bead starts with good foiling. The foil should be fresh and without corrosion. The joints need to be tight fitting with a space no more then 1/16" gap. Some people claim that you need to leave gaps in between pieces or the project won't be strong. This simple isn't true. Make the joints as tight fitting as you can. The project will look better and will be lighter as well. The foil needs to be rubbed on tightly, or it will peel up. The glass has to be clean as well. For more information on better foiling see: The Foil FAQ
Set up the area where you plan to solder. Plug the rheostat in, and set it to about 7 or 8 (range is 1-10). Plug the soldering iron the rheostat. Let the soldering iron heat up. While it's warming, get everything else ready. Tools, tinning equipment, solder, flux, a brush, and so forth. Don't forget proper safety equipment: goggles, gloves, apron, etc. Don't forget to turn on the fans.
Start by cleaning the iron on your tinning block and wipe it on your sponge. A good bead requires a clean iron. If any of that crud is on the tip, it needs be removed, or it may fall into the bead. If the crusty parts aren't coming off the iron, the tip may be bad and it needs to be replaced. To learn more on soldering iron maintenance see: How To Maintain Your Tools.
Apply flux to the foiled lines, dab some on the joints that come together (where several pieces come together). Tack solder the joints, use 50/50 and tack the wherever you can. Remove any tape that may have been holding the project together. Apply more flux (a thin coat as if you were applying a Bar-B-Q sauce over a tasty morsel). Use the 50/50 to fill in the joints or gaps. You may have to raise up the temperature for this.
Flip the project over flat solder the back. If you want you can solder the back as well. (If the it's a large panel, you can do this step after the front is beaded).
Sometimes I find that I need to remove the old flux prior to adding the new. Old flux won't work, and too much flux won't work. I wipe down the project, using water or denatured alcohol. You'll know there's too much flux, when the iron can't keep up, it won't melt the solder. It also may make the solder pop - when the solder pops molten droplets of hot solder spray over your body. This is the most likely happenstance.
Re-flux the area, but only flux a small area. Flux and area that will take 5 minutes to solder. Otherwise the flux may evaporate, and you won't be able to form an even bead.
It's really tricky to describe how to solder in an all text format. It's easier to see. But I don't have movies or pictures, I don't have the equipment, but I certainly wouldn't mind if anyone sent some over my way, hint, hint. The best I can really do is to describe things the best way I can, and it will have to do. Just close your eyes and imagine be explaining it to you, oooh wait, stop soldering first.
Hold the soldering iron, so the face of the tip (the wide part), is at a 45-degree angle, and the iron is also at a 45-degree angle. Like holding of a pair of chop sticks (that angle). The corner of the tip will be the "spout, or funnel" for the solder to flow off of. By the way, the angle isn't absolutely critical. I've held the iron perpendicular to the work. Or almost flat up against it.
Feed the solder at the top of the tip, this is where the bulk of the heat is. When you solder, you have to keep an eye on several things:
The iron tip shouldn't actually touch the project. It should float about 1/16" or so off the panel. I touch the tip to the foil, the soldering iron can get heavy after a while, and my arm get's tired quickly. Doing so could snag the foil underneath the tip and rip the foil.
What you want to see is a column of solder coming off the tip. Try this experiment below:
Beakman experiment: Get your parents permission before you try this.
You will need the following:
Fill the glass with water. Put your finger in the water and slowly remove it. Stay about a 1/16" above the surface lever of the water. A small column of water will form there. That little bridge of water is what you're looking for when you solder. It basically forms a meniscus. As for the matches and newspaper, be creative.
With all that in mind, melt the solder and slowly draw a bead. Pull the iron across the surface. It's like squeezing mustard on a hot dog. Watch the bead as it forms, as you approach a joint, pass over it (about 1/2"); imagine a T. Then go back to the bead you just made; the solder works best when still warm. The joint is the toughest part, due to overlapping. By doing the joint now, you'll save yourself the trouble later on, it tends to make a messy joint later on. As you solder, there isn't any one correct path. It actually snakes around the project. Just stick with a small area, no more then 8"x8" (if they are small pieces), and you'll be fine. Also you don't want to go over a bead more then you have to. The more you go over it the worse it will be. Solder contains various ingredients, these components don't mind so much the first time, but repeated heating's will make the solder very un-manageable. So as you continue soldering the rest of the project, you'll have to be careful of the beads you just made. Try not to go over them if you can (just a small area of the bead when you continue an adjoining solder line).
A few rules to keep in mind:
An Alternate method is the dab technique:
Apply some solder to the joint, a small lump. Lift up the iron, move over about a 1/2" do it again. Go to another spot, and another. Then connect the two original spots together and so forth. This technique is good when your getting soak through, or just when you don't want to apply too much heat on something. I use this method when beading the thin foiled edge on a box. If I used a long continuous bead, the foil lifts up. Dabbing it real fast helps to stop this from happening. It's like connecting water droplets on a window (with your finger).
A few descriptions of what your solder may look like, and what the problem may be.
Started on 11-5-00