Choosing a Flux

Before picking a flux, it’s useful to have a good definition of flux:

Flux is a chemical composition critical to the heat joining methods of soldering, brazing and welding that:

  1. Chemically:
    • Cleans metal surfaces to assist the flow of filler metals over base metals.
    • Provides a protective barrier against re-oxidation and heat scale.
  2. Thermally: Assists with heat transfer from the heat source to the metal surface.
  3. Physically: Helps in the removal of surface metal oxides.

Step 1 – Are you soldering, brazing or welding?

Your first step in choosing a flux is in determining the type of metal joining process you are engaged in – soldering, brazing, or welding. The following are useful definitions of each process:

Soldering: A process where similar or dissimilar metals are joined using an alloy that typically includes a base of tin combined with lead, silver, antimony, bismuth and indium. Soldering also includes processes where a metal is coated or tinned with a solder. Soldering processes cover a temperature range of 60°C – 440°C/ 140°F – 825°F. Soldering is used in electronics, plumbing, electrical wiring, stained glass and a host of industrial and commercial uses.

Brazing: A process where similar or dissimilar metals are joined using an alloy that typically includes a base of silver combined with nickel, copper, and zinc. High temperature brazing, often used for carbide products, may employ alloys that do not contain silver, but contain rather nickel, copper and manganese. Brazing covers a temperature range of 470°C – 1190°C/ 880°F – 2175°F. Brazing is used for compressors, engine circulation tubes, mining tools, plumbing fixtures, jewelry, musical instruments and a variety of other applications.

Welding:
A process whereby similar metals are joined using a direct heat source to melt the base metal and filler metal to create a uniform finished product. Most welding involves iron-based metals such as steel and stainless steel, but welding is used in other metals, such as aluminum. Welding covers a temperature range of 800°C – 1635°C/ 1475°F – 2975°F. Welding is used in forge and farrier applications, oil pipelines, blacksmithing and many other applications.


Step 2 – You’re not sure if your process is soldering, brazing or welding?

Contact us!

We mean it. Our telephone is (+01) 440.349.3000 (USA). Our fax number is (+01) 440-349-3003 (USA). Our e-mail is info@superiorflux.com. We want to hear from you. If you call during office hours, you’ll get a live voice. If you e-mail us, you’ll get a response.

We’re interested in learning about your application and will do what we can to supply you the right flux, regardless of how much you need.


Step 3 – You’ve determined if your process is soldering, brazing or welding.

Our webpage is broken down according to the general metal joining applications.

We’ve broken soldering down into two categories – Industrial Soldering Flux and Electronics Soldering Flux. We treat Brazing Flux, Aluminum Flux and Welding Flux as their own categories. We’ve also added a few additional categories. Here’s the breakdown:

Superior No. 30 SuperSafe Soldering Flux: No. 30 is a great all purpose flux with so many uses and such a great track record that it merits its own page.

Industrial Soldering Flux:
If you’re not soldering printed circuit boards (PCBs), semi-conductors, or component lead tinning, then you probably belong here. Scan the different web pages, broken down by application, and see if any apply to your application. If you’re looking for general purpose active fluxes that will work with stainless steel or other ferrous alloys, go to Stainless Steel Soldering Flux.
Electronics Soldering Flux: If you’re soldering printed circuit boards (PCB’s) or doing wire or component lead tinning, semi-conductors or component lead tinning, you belong in this section. The Overview for Electronics Soldering Flux is organized according to the various stages of PCB fabrication and wire/component tinning.

Aluminum Flux: We supply fluxes for all types of aluminum joining: soldering, brazing and welding. We offer the broadest range of aluminum soldering fluxes on the market.

Brazing Flux:
Our brazing fluxes are broken down according to application. See our general purpose Silver Brazing White Flux Paste, and our High-Temp Black Brazing Flux Paste. We have a particularly strong line-up of Carbide Brazing Flux Paste. The Brazing Flux section also includes a wide variety of additional brazing applications, such as aluminum brazing and jewelry brazing.

Welding Flux: As with the other categories, welding is broken down according to application. Our Anti-Borax Fluxes division has been selling welding flux to blacksmiths for over a century.

Tube Welding Flux:
Our tube welding fluxes offer stainless steel tube fabricators an opportunity to greatly reduce defects and potentially eliminate the use of costly argon and other inert gases in tube welding applications.

RubyFluid Flux: In 2010 Superior Flux purchased the RubyFluid Flux line. We are proud to manufacture this line of soldering flux that has been a favorite among roofers, artisans, plumbers and other assemblers for over a century.


Step 4 – You’ve reviewed the web page and still can’t determine which flux to use?

Try one of one of the following tools we have designed to help you pick the right flux:

Flux by Application
– An easy-to-use flux chart that matches fluxes with applications.
Flux by Specification – A chart that lists fluxes per various industry and/or government specifications.
OR
Contact us!

Don’t hesitate to call (+01) 440.349.3000, fax (+01) 440-349-3003 or e-mail (info@superiorflux.com). We’re here to help. Sometimes a phone conversation or e-mail is all it takes for us to identify the right flux.

In some cases we ask customers to send us components, and we experiment with them in our laboratory to determine the optimum metal joining process. Often we not only recommend which flux to use, but make recommendations on solder alloy, base metal and the actual metal joining process. We have a lot of experience with metal joining and are happy to offer our expertise.

It is also not uncommon for us, depending on the application and location, to send a metal joining specialist to your factory floor to analyze your specific metal joining process for the purpose of recommending a flux solution. We also offer Flux Consulting and Lab Services in which we provide in depth professional analysis of your metal joining processes at your site or professionally analyze your joining or tinning applications in our laboratory.


Step 5 – Sampling and Opening an Account

As a matter of policy, we don’t send out free samples. We do however sell flux in small test quantities. We charge reasonable prices for these trial orders and can accept credit card payment.

First time orders are often made with credit cards, which enables us to supply new customers quickly. Opening a credit account with Superior Flux involves sending in credit references. Customers are given Net 30 terms according to credit assessments and ongoing credit worthiness, and Superior Flux always reserves the right to require prepayment for an order.

You will find the ordering process, regardless of order size, to be a pleasant and efficient experience. We ship the majority of our orders within two business days of receipt of order.