Soft Solders

Used for centuries as a means of joining metals together, solders are ideal for lower temperature applications. Bellman-Melcor (A Prince & Izant Company) has been providing the highest quality solder alloys and fluxes to meet our customer’s unique requirements and applications. With more than 150 solder alloy combinations to choose from, customers can be confident that the precision engineered solder alloys and preforms that they order will meet their exact specifications including electronics applications where high purity solder alloys and “no clean” flux systems are required. Soft Solder alloys are used for metal joining processes that occur below 840⁰F. The appropriate solder alloy may be determined by considering the base metals being joined, the in-service temperature of the application and temperature of any next-assembly processes, and soldering process.

Soft Solder Alloys

Bellman-Melcor provides a variety of soft solder alloys, including common tin-lead solder and lead-free solder. Please note that it is not legal to use lead-bearing solder in public or private potable water systems. Many states have laws prohibiting the sale of lead-bearing solders in plumbing supply businesses. 


Soft Solder Fluxes

Bellman-Melcor distributes a complete line of solder fluxes for all applications. For unique situations, we deliver formulations specifically designed for your application. Choose from the following primary families. There are three different categories of soft soldering fluxes: Inorganic Acid Solder Fluxes (IA), Rosin Solder Fluxes, Organic Acid Solder Fluxes (OA).


1077 The Inorganic Acid (IA) fluxes are used primarily for industrial soft soldering applications. These fluxes typically contain a combination of zinc chloride, hydrochloric acid, and ammonium chloride. These fluxes are used for soldering stainless steel, brass, copper, and other metals commonly joined in industrial applications. Other inorganic products are hydrobromic acid based fluxes. These fluxes are used for conventional radiator soldering applications. Today, many regional sewer districts are monitoring the emissions of heavy metals into sewer systems. New alternatives are being sought to eliminate zinc (a heavy metal) from fluxes and remove the hazardous waste associated with post-solder effluent.

The Rosin Fluxes have been a standard in soldering for more than a century. These products are based upon abietic acid, found in tree rosin, and are available in three types:

  1. Type R (Rosin). A combination of Water White (WW) Gum Rosin blended with solvent.
  2. Type RMA (Rosin Mildly Activated). A blend of WW Gum Rosin, a low activity activator, and solvent. Meets most military specifications.
  3. Type RA (Rosin Fully Activated). A blend of WW Gum Rosin, a high activity activator, and solvent. For applications needing highest activity.

While these fluxes have been the standard in soldering for many years, the cleaning requirements for rosin fluxes typically involved Freon° or Trichloroethane 1:1:1. With the implementation of the Montreal Protocol, today most manufacturers have shifted from CFCs to HFCs or aqueous and No-Clean fluxes.

1075 The Organic Acid (OA) fluxes are available in a variety of formulations, including water-soluble and No-Clean fluxes; halide and non-halide fluxes; alcohol and VOC-Free (water-based) products. OA flux was first introduced in the 1940s. Based upon a formulation conceived at the Battelle Memorial Institute, this flux contained no rosin, no inorganic activators, and no solvents. It was a revolutionary chemistry that was capable of soldering copper, brass, and nickel alloys, but contained only one-third the solids content of the conventional rosin fluxes. Cleaning was simplified to an aqueous wash using an OA flux. The cleanability and activity of this flux, relative to Rosin and Inorganic fluxes, made it popular for electronics and electrical soldering applications where more activity was required than found in rosin fluxes, but did not have the corrosive and cleaning problems inherent in acid fluxes. Today, manufactures worldwide are switching to No-Clean fluxes, and VOC-Free, and water soluble fluxes in an effort to promote a safer workplace and global environment. These fluxes comprise the majority of liquid fluxes sold for electronics assembly applications in wave soldering, component tinning, and wire/cable tinning.


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