The other day, we asked a simple question on Facebook and Twitter: “How old were you when you first learned to solder?” Of the many responses, one of our favorites was, “RadioShack should have a soldering demo station at its stores. I think people who weren’t taught are intimidated by it.” We totally agreed about the intimidation factor, and the soldering stations sounded like such a promising idea … until the legal team pointed out what an unattended 5 year old could do with a 750-degree pointy object. Still, we think more people should learn how to solder. You can build awesome gadgets and repair things around the house, but more importantly, melting metal with a magic wand is just awesome. Here’s a little soldering 101 to help you take your first steps toward DIY.
First, you’ll need some supplies. We’re going bare bones here so you won’t break the bank if you want to give it a shot.
Soldering irons come in all shapes and sizes, but if you’re just starting out, there’s no need to spend an arm and a leg on one with all the bells and whistles. We have several models that will cost you less than $10. If you’re going to be soldering components to a circuit board, your best bet is to use a low-wattage iron (15-40 watts). More powerful irons will be too hot and risk damaging delicate components.
For most soldering jobs, we recommend standard 60/40 rosin core solder. The .032’’-thick variety is perfect for most detail work like printed circuit boards and our DIY kits.
Something to Solder:
If you’re a newbie, don’t start out promising your spouse you’ll fix the busted TV. Do a simple project like this Velleman Flashing LEDs Kit. There are tons of cool hobby kits just like this one at RadioShack stores, and they’re perfect for getting started with soldering and DIY. They have all the parts you need and they tell you exactly where to put them. It’s like paint by numbers with molten metal.
You’ll also need a damp sponge for cleaning your iron, a set of diagonal cutters for snipping the component leads and a 9-volt battery.
Nice to have: The RadioShack Helping Hands with Magnifier to hold the circuit board still while our hands were full. One joint was a little extra goopy, so we sucked up the excess with a Vacuum Desoldering Bulb and resoldered. It’s also great for salvaging parts from old electronics.
Now, on with the show.
Plug in your soldering iron and wait a few minutes for it to heat up. If it’s not hot enough, you’ll end up holding it near the components for a long time waiting for the solder to melt, which can damage your parts. It should go without saying, but DON’T TOUCH THE TIP OF THE SOLDERING IRON.
Next, clean the tip on the wet sponge. Don’t worry about the sizzle; that’s normal and it’s how you know you’re up to temperature. If you’re working with a brand-new iron, put a little bit of solder on the tip. This is called “tinning” your soldering iron and it helps heat flow from the tip to the joint you’re soldering. You only have to do this once. After it’s been around the block a few times, there should always be a little solder on the tip.
Now you’re ready to solder your first component onto the board. Our Flashing LEDs Kit instructions tell us to start with a 1K resistor. Place it in the spot labeled R1. Get it as close to the board as possible and let the extra lead wire stick out the bottom of the board. To keep it stable, bend the leads outward.
Now, put your iron tip on the resistor lead and the exposed copper area on the underside of the board and let it heat up for a few seconds. Then, place the solder up to the heated area.
The solder should melt and flow around the lead and form a solid joint. Resist the temptation to touch the solder directly to the tip of the iron. It will melt really quickly, but the solder won’t flow INTO the joint, instead pooling AROUND the component lead. Once you have enough solder joining the resistor to the board, move on to the next one. Try to keep things as clean and “un-blobulent” as you can. The joint should look like a little silver Hershey’s Kiss and should be contained within the exposed copper area surrounding the hole.
Repeat the procedure with each component. When they’re all in place, you can solder the wires to your 9V battery connection and test it.
The two LEDs should be blinking about once per second. If not, it’s time to check for mistakes. Soldering is a pretty forgiving process and you can reheat the solder again and again, so just check your joints for too much or too little solder. Our test run revealed that we had one cold solder joint. That means the solder wasn’t hot enough and didn’t join properly with the board and the component. Either our iron wasn’t hot enough or we touched the solder to the tip instead of getting the entire area hot enough. If the solder is dull and grainy instead of shiny and smooth, it’s likely a cold solder joint.
Watch out for too much solder, too. If two nearby blobs accidentally touch, you could end up with a short. Reheat the joint and use the desoldering bulb to remove the excess and try again.
There you have it. If the thought of holding a 750-degree pointy thing in your hand was a barrier to your DIY dreams, we hope we’ve demystified it for you. Practice makes perfect so grab one of our hobby kits today. You’d be surprised how satisfying two little blinking lights can be when you build it yourself.