A Soldering Tip... or Two

By Robert Cong

The Equipment Makes a Big Difference

Soldering like an expert requires skill and practice, but upgrading your soldering equipment will make a big difference as well. This article provides suggestions about how to improve your results with soldering tips plus an introduction to new products that you'll love.

The Tip is the Tool

According to our friends at Weller, one of the largest soldering iron manufacturers in the world, "The tip is the tool!" The tip, the most critical component of the solder iron, must transfer heat efficiently and reliably to the connection point. To transfer heat effectively, it is extremely important that the tip is maintained according to the highest standards of care.

Polishing Bar
Weller WPB1 Polishing Bar

Tip Care

  • Keep the tip tinned with a thin coating of solder at all times to prevent oxidation and enable heat transfer
  • Use distilled water to keep sponge damp (not drenched)
  • Keep the sponge clean
  • Higher temperatures lead to reduced tip life, so maintain operating temperatures as low as possible
  • Use the Weller WPB1 polishing bar to prevent or remove oxidation. When the tip is cold, lightly polish it and remove oxides,
      then immediately re-tin the tip
  • Using rosin activated flux cored solder can help remove oxide buildup
  • Tinning the tip forms a heat bridge between the tip and the parts being soldered. The tin coating will flatten out as the tip touches the connection, creating a larger surface area and more efficient heat path than a "dry" or untinned tip.

Choosing the Solder

When choosing the type of solder to use, note that lead-free solders with a higher tin content will attack the iron plating on soldering tips and reduce tip life. Also, solder wire with smaller diameters often contain flux voids that may cause tip oxidation. For certain applications, it may be a good idea to stay away from water-soluble core solder wire as well as water-soluble flux, as these are corrosive at high temperatures and will accelerate the damage to your soldering tip, causing early tip failure.

The composition of solder wire to use depends on what you're using it for. Differences in tensile strength, melting point, and freezing point may play a significant role in your applications. The most common mixture for solder is tin (Sn) and lead (Pb), with 63% Sn and 37% Pb being the perfect chemical composition that allows solidification at a lower temperature than any other mixture of the two.

Properties of Solder Compositions

Harder solder, which contain alloys of copper with silver or zinc, are necessary for braze soldering because of the higher melting temperatures.

1-Pound Solder Roll 63% Tin, 37% Lead

Lead-free solder requires higher soldering temperatures and should contain at least 2-3% flux by weight for good wetting behavior. Keep in mind that lead-free solder will reduce the life of the tip, so be sure to use tips that are designed for lead-free solderin .

Hand Soldering with Lead-Free Solder

When it comes to choosing the type of soldering iron, you have many options, but you want something that feels comfortable in your hand and is sized adequately for your work space. There are portable soldering irons that are butane-powere or USB-powered, self-standing soldering irons, and replacement irons for your soldering stations.

LED soldering irons from Weller offer 3 LED illumination with bright focus beams, and co-molded grip for maximum comfort and reduced slippage. See chart and video below.

LED Soldering Iron
Click for larger photo

No matter how you solder, you want to have a nice, clean finished product and the best way to get that is to know the parts you are dealing with. If you need some more help in choosing soldering equipment, check out the Soldering Equipment and Accessories article.

Robert is a graduate from Cal Poly, San Luis Obispo in Electrical Engineering. His interests include sports, movies, music, and playing with cool, new gadgets.