Most of the things I am about to say will cause you to say, "Duh!" because they seem obvious, but it's easy to get so in to the art part that you forget the common sense part. At least it is for me. =o)
This assumes you have already read my previous soldering blogs parts 1, 2 & 3... If not, ya might want to check 'em out.
1. Don't solder naked! A. Because it's just not pretty and B. Because solder & flux can splatter and drip. Make sure you solder over a heat resistant surface. Make sure your hands are higher than the molten solder at all times so you cannot get burned if it runs and drips. Wear shoes. Wear safety glasses. Wear a mask. Wear a smile.
2. Gravity applies to molten solder. Pay attention to the angle of the piece when you are soldering. It's natural to want to tilt the piece back to get a better view of the solder you are trying to add to the front, but don't be surprised when the solder runs to the back. You can use gravity to your advantage to manipulate where the solder goes. You can also use it to remove excess solder. Melt extra solder and push it off the end that is pointed towards your heat resistant work surface.
3. Always keep your soldering tip silvered and keep a spare soldering iron tip on hand. Wipe the solder tip on a wet sponge often while in use to keep it clean and from overheating. Don't leave the iron idol just cooking away. Unplug it if you are not going to use it right away. They do wear out because of the extreme heat. Tips can become pitted and can quit working right in the middle of a project. If the tip no longer appears silver, it will not work properly. See the troubleshooting section below for more information.
4. Don't mix ammonia with blackening agent. If you will be using a patina, it most likely contains an acid that is very toxic and corrosive. Most become extra nasty if combined with ammonia. Guess what is in your average glass cleaner that you probably use to clean your slides? That's right... ammonia. Do NOT mix. Use gloves, eye protection and major ventilation and follow all of the manufacturers cautions to a T when using patina. Dispose of leftovers appropriately. I recommend not pouring this stuff into a cup to use it, but sit the bottle in a big non-tipsy bowl, open it, and use a long wood handle Qtip (like the doctors use to swap a throat) to dip into the bottle. Pull the swab out, then immediately seal the bottle and apply the patina to the solder. This way there is minimum exposure and little waste to dispose of. Wear gloves. The stuff can burn skin.
5. Smoke goes up. Duh, right? But solder smoke in particular likes to rise strait up quickly in little bursts. If you are leaning over the item you are working on, it will go straight in your face & up your nose. This smoke is unhealthly at the very least even when it says "non-toxic solder". Certain solder fumes can cause lung disease over a long exposure. Do NOT breath the smoke. Wear a mask with the proper filtration rating, use fans and good ventilation. Don't hover over the item you are working on.
6. Gravity applies to hot soldering irons. Most soldering irons have heavy duty stiff cords that may actually weigh more than the iron itself. If the cord dangles off the side of your work surface, it may actually pull your soldering iron over the edge too which would be really bad if it is hot. Use a soldering iron stand with a heavy base, and/or use a piece of duct tape to tape the stand base and the base of the cord to the work surface.
7. Remove all flux from glass and solder immediately after it cools. Flux is an acid and it will continue working and could etch the glass and discolor the solder. You can then patina the solder or polish it to a shiny silver using a solder polishing compount. To maintain the color of the solder, seal with wax. You can get the patinas, compounds and wax at any stained glass supplier.
Here are a few common problems and some likely causes why they might occur.
The copper tape lifted off the glass during soldering or after - The tape had a spot of poor adhesive, or it was not burnished to the glass thoroughly before applying flux and the flux got under it. This can be even more of an issue if you use multiple strips of tape vs. one continuous piece.
The copper tape got a hole in it while soldering or stuck to the iron - The soldering iron was held in one place for too long or you went over and over the same area trying to smooth the solder. If you can, try pealing it off or covering with new tape, flux and solder again.
There are tiny pinholes or bubbles in the solder - Your copper tape is not good quality or it was not adhered well and the glue melted up through the solder when it was heated. Or you used too much flux and it boiled and made bubbles.
The soldered edge is skinny on one side and fat on the other - This is most likely because the copper tape was not centered on the glass edge. Or it could be that the glass was tilted during soldering so more solder flowed to one side than the other.
The soldered frame is crooked - Most likely caused by not putting the tape on straight. If the tape is crooked, you can use an exacto knife to trim before you solder or remove and put a new piece on.
The glass broke - A single area of the glass got too hot during the soldering process because the iron was held in one place too long. Or, the items sandwiched between the glass were too lumpy. Lumpy items must be balanced with other lumpy items of equal height between the glass so the glass cannot teeter-totter and get stressed enough to break.
There is fog or moisture under the glass - The items between the glass were moist, probably from glue that was not yet dry. The heat of the soldering iron created steam. Or, after soldering, cleaning solution or other liquid ran under the solder. Solder does not make a watertight seal. Items should not be worn in the shower or even in heavy rain.
My soldering iron will no longer melt the solder - Or the solder gets stuck to the tip. Verify that the melting point of the solder you are using is low enough to be melted by your iron and that your iron is fully heated. Check the iron tip. If the tip of the iron no longer appears silver even after wiping on a damp sponge, try sanding it with sanding paper (while it is cool) to re-expose the silvered tip. Heat and resilver the tip. If that does not work, you can try a Sal Ammoniac* block. This stuff is nasty and toxic. Do NOT breath the fumes. Here are some great instructions from Volcano Arts on cleaning your soldering iron tip. If cleaning does not work, replace the tip when the iron is cool. It is easy... There are usually one or two tension screws to loosen and the tip should come right out. If it is stuck, try tapping it lightly or twisting with plyers. If all the above does not work, it may be the iron itself or the electrical outlet.
*Note, this is ammonia... as mentioned above do not EVER mix patina solution and ammonia. Store these items faw away from each other.
My solder is lumpy - Practice makes perfect. Use one fluid motion like a long painting stroke to float the solder along the tape with the iron barely touching to make the smoothest bead. Be sure to hold the tip so you are using the wide, flat edge. Also, it helps to have a good iron that keeps a constant temperature. Most importantly, flux well and often. Solder cannot flow without flux. Make sure you coat the whole section to be worked with flux but don't try to do too big of an area at once. If you flux and don't immediately solder, reapply flux.
Don't let the above intimidate you from trying soldering yourself. Yes, there are a few issues and some safety things to think about, but anyone can do it and you can produce really pretty piece that you and others will love very quickly and economically. Happy creating!