Solder And Types Of Solder

Solder wire is an alloy usually made of different metals, i.e. [lead (Pb) & Tin (Sn)], having a lower melting point than any of the metals being joined.

Solder Wire:

To understand solder and soldering. So here are a few tips some of you might find helpful:

1. Solder is used as glue to hold pieces of metal together and conduct electricity and heat between them.

2. To do this, you need to apply a metal with a melting point lower than any of the metals being joined, or they will melt first.

3. We could use lead for almost all electrical work, which is very cheap but melts at about 328C (622F). Tin is expensive but melts much more efficiently at 232C (450F).

4. We get an alloy that melts even more efficiently if we mix Tin and lead together. It turns out that 60% Tin and 40% alloy (60/40), like this solder, melts at 188C (370F). Even better, but more expensive and hard to find, is 63% tin and 37% lead, which melts at about 183C (361F). Plumbers use 50% tin and 50% lead alloy, melting at about 214C (418ºF). Avoid it for electrical/electronic work.

Application	State	Alloy and %	App Melting Temp
Jewellery	Hard	76% Silver( Ag) 21% Copper (Cu) 3% Zinc (Zn)	About 772C / 1426F
Plumbing	Soft	97% Tin (Sn) 3% Copper(Cu)	About 200C / 400F
Electrical	Soft	99.3% Tin (Sn) 0.7% Copper(Cu)	About 227C/ 440F

5. To get a good solder joint, the parts to be joined MUST be clean! Use a wire brush or sandpaper (not steel wool, bits of which can drop on your work and create short circuits.

Solder And Types Of Materials They will Join:

Most of the solders are specific in function. Therefore the solder should be used chose carefully before soldering. The below table shows the type of solder and their uses.

Solder	Used For
Tin-Lead	It is used for soldering Copper and copper alloys, mild steel and galvanized metal.
Tin-Antimony	It is used for soldering Copper and copper alloys mild steel mostly.
Cadmium-silver	It is used for soldering copper and copper alloys mild steel and stainless steel
Cadmium-zinc	It is used for Aluminum and aluminium alloys

How To Solder Wire:

Wrap the CLEAN wires together or clamp your CLEAN work so it will not move after you remove the soldering iron. Press the hot iron against the joint and touch the solder wire to the iron tip to contact the common. Let a minimal amount of solder melt and get drawn into the joint to help heat travel into the joint. Then touch the solder to the part being soldered. To get a good joint, the JOINT, NOT THE IRON, must melt the solder. The solder MUST “wet” the joint and flow into the joint smoothly. Move the iron away carefully and let the solder cool. It takes a few seconds for the melted solder to cool. During this time, the alloy is slushy, and movement, before it cools, will result in a weak, rough-looking “cold solder joint,” which is unreliable and must be re-melted. Do not try to melt a blob of solder onto the iron’s tip and carry it to the joint. The flux will be gone, and the solder won’t flow properly.

7. The slushy phase is very short for 60/40 solder but can last for many seconds for 50/50. Plumbers used to take advantage of this to make “wipe joints” by wiping and forming the slushy solder with a rag as it cools. That is very seldom done these days–and NEVER in electronics. 63/37 solder goes from a liquid to a solid almost instantly, making cold joints rare. Buy it if you can; you use tiny per joint in electronic work. I bought a 1-lb spool of it many years ago and still have most of it. I misplaced it recently, which is why I am here on Amazon.

Flux:

Most metals quickly react with air to form an oxide film, starting as soon as cleaned. Aluminium is an active metal that would be unusable outdoors if its oxide film did not protect it from corrosion. It makes soldering very difficult, so it’s usually crimped or welded. Copper and brass oxide films will also prevent solder from adhering. Even if you CLEAN before soldering, you need a flux to dissolve and avoid oxidation at the joint during soldering. Acid flux is used in plumbing as it is very effective, but it is corrosive and must be removed after the joint is made. Rosin-based change is less corrosive and can be left in place. It is usually supplied within the centre core of electronic solder, so you don’t need to buy a can of it unless you are plumbing. More

Secret Of Soldering:

The secret of soldering: Lots of heat, for a short time. Trying to protect parts from the heat using a low-temperature or little iron will result in MORE overheating of the components. The heat will have more time to travel to the part even if the solder joint is unsuccessful. Do this: Use an excellent temperature-controlled soldering iron such as a Weller, Hakko soldering station.

I use 600F temperature tips for 60/40 solder, though 700F might be better for lead-free solder. Keep the tip clean by melting a bit of solder on it and wiping it off quickly with a damp paper towel or sponge to get a smooth silvery surface. Modern irons come with iron-plated tips for long life. NEVER try to file them as your grandfather did!

If you are a newbie, you ought to get a training kit to start. I recommend you buy Best Beginner Soldering Iron for your kids, nieces, nephews, and friends who want to learn to solder. These come with proper tools (though the soldering iron will not last 40 years like my W-60.) There is an excellent instruction sheet for soldering and de-soldering, with a simple circuit board and parts to work with and, hopefully, build a working gadget—all at a low price. More…