How To Solder Like A Pro
Soldering is a learned skill. With the right tricks, you can be a pro in no time.
Soldering can be a difficult skill to master, but with the right knowledge, you will find it an easy one to understand. There are a number of rules to follow when soldering, many of which are often broken by the unskilled. Here is a list of just a few of those rules.
*Too much is NOT a good thing.
*Never apply the solder directly to the iron and attempt to 'paint' it onto the metal.
*Yes, you CAN apply too much heat.
Soldering takes patience. This is the most important part of learning to solder. You must wait if you want to have a good solder joint. So you need to understand that this isn't a speedy process.
First I'd like to go over caring for your soldering iron. You need to take care of your tips. If you get a coating of melted plastic on your tip, it needs to be replaced. The plastic draws heat from the tip, and you can end up with cold solder joints. You also need to be careful about cleaning your tip. If you scratch it up, it will again lose heat too quickly. Buy a simple soldering stand, with a holder for the iron and a small sponge on the base. The sponge is used to clean the tip while soldering. You need to soak it with cold water, and should use it to clean the tip between each joint that you solder. This helps to keep the tip working at peak efficiency. When you are done soldering, always put a large blob of solder onto the tip as it cools. This keeps the tip sealed nicely, preventing oxidation.
If you are using your soldering iron for the first time you need to tin the tip. This is also true if you are using a new tip for the first time. Tinning is the process of heating up the iron and applying a thin coat of solder to the tip. This helps to achieve maximum heat transfer to the item you are trying to solder.
Now that you have a well maintained and prepared tip, it's time to do some soldering.
First, you need to prepare the surface you will be soldering. If there is already solder on the area you are to work with, you must remove it completely. This can be accomplished with a de-soldering braid. This is a small spool of braided copper that, when heated by an iron, will draw the solder away from your work area and onto itself. Soldering braid can be found at any electronics supply store. You need to be careful to heat the braid, not the solder, allowing the heat to transfer from the braid to the solder. If you lay heat for too long to a contact on a circuit board, you can easily destroy the contact, or land as it is called.
Once you have removed all the solder and cleaned the area with isopropyl alcohol, you are ready for the next step. The next step is preparing the surface for new solder. This is accomplished through tinning the contact or wire with a thin layer of solder. This can be skipped on circuit boards, as the risk of destroying the land is too great.
After you have tinned the surface or wire, you will then lay the tip of the soldering iron against the metal pin on the board, or to the wire if you are splicing. A trick here is to touch just a small amount of solder to the tip, allowing just enough to from a bridge between the tip and the item you are trying to solder in place. This allows for a greater transfer of heat and speeds up the process. Once the bridge has been made, you then lay the end of the solder against the metal you are soldering, careful to keep it from touching the tip of the iron. Doing this makes certain the entire item is hot enough to melt the solder, thus making an ideal joint.
Once the solder begins to melt, feed it into the joint until there is enough to fill the gap and leave a slight bubble shape. When removing the iron, be careful not to shake or bump the metal you are soldering. This can result in a cold joint which will crack over time. I recommend sliding the tip straight up the pin, if such is what you are soldering, otherwise, just remove the tip smoothly, with an upward motion.
A good joint will be shiny and smooth, with a slight bubble shape to it. It will not completely cover the pin, but incase it, leaving the tip to stick out of the top of the bubble. It will not have any dents or open spaces.
A bad solder joint will look dull, more grey than silver. Or if it has a little curl at the top it needs to be redone. If you need to redo a solder joint, always start from scratch, removing the solder you just put on, and cleaning the surface with alcohol. This will be frustrating at first, but as your skill grows, you will do this less and less often.
Most solder has what is called flux, or rosin, in its core. This aids in the heat transfer but leaves an ugly residue. Clean the solder joint with alcohol before you make a decision on whether it is a good joint or not. Flux residue can hide a bad solder joint.
Splicing wires is another task best done with solder. There a number of ways to splice a wire, I will go over the strongest splices here. First is the eye-hook splice. You take the one side of the wire and bend the bare wire back onto itself, creating an eye much like you would find on a needle. Wrap it a few times to strengthen the tie and then tin the wire. You only need to leave an eye big enough to snake through the other piece of wire. Once you have snaked the other piece through the hole, make another eye with that end, locking the two pieces of wire together. Tin the new eye just as you did the first. Use pliers to flatten the area where the two eyes meet and then solder them together. Then solder the whole thing with a thin layer. You should be able to see the shape of the strands within the wire when you are finished. This is the strongest method of splicing wires that I know.
There is one other method I will be discussing that is not nearly as strong but is much quicker. This method is good for using in situations where no stress will be put on the wires. Take both sides of the wire and splay out the strands. Then bring both sides head on to each other, allowing the strands to mix into kind of a handshake. Then twist the strands so that they grab a little, allowing you to let go of the wire. Now you simply solder the area where the two strands have met, going back about a half an inch in either direction from where they no longer intermingle.
Always use just enough solder in whatever you are doing. There is such a thing as too much. Too much solder lends itself to a cold joint, or cracking later on. Remember to take care of your iron, and it will take care of you. Also remember that the fumes of certain types of solder are not good for you, so wear a mask and always solder in a well ventilated area. I would also recommend wearing safety glasses at all times, as you will find yourself leaning over your work, bringing your eye dangerously close to some very hot substances.
Good luck, and be patient.