Earlbeck Gases & Technologies
  • Products & Services
    • Fronius Welding Products
    • Welding & Cutting Equipment >
      • Free Welding Productivity Analysis
    • Welder Rentals & Repairs
    • Engineering
    • Machine Tools
    • Welding & Cutting Automation
  • Gases
    • Free Gas Application Analysis
    • Industrial & Welding Gases
    • Bulk & Microbulk Gas
    • PurityPlus Specialty Gases
  • Welder Training
    • Program Overview >
      • Fundamentals of Welding
      • Intermediate Welding >
        • Intermediate Stick
        • Intermediate TIG
        • Intermediate MIG >
          • Intermediate GMAW - Aluminum
          • Intermediate FCAW Self Shielded
          • Intermediate GMAW - Stainless Steel
      • Advanced Welding >
        • Advanced Stick
        • Advanced TIG
        • Advanced MIG
      • Welding Basics
      • Custom Classes & Open Practice Time
    • Pricing and Class Schedule
    • How to Register
    • Tour Our Facility
    • Why Earlbeck Technical Center
    • On Site Training
    • Frequently Asked Questions >
      • Are student loans, financial aid, or scholarships available?
      • How long does it take to complete the program?
      • Do you offer job placement?
      • How Much Money does a Welder Make?
      • What is the Job Outlook for Welders?
      • What should I bring for my first day of class?
  • Weld Testing
    • Welder Certification
    • Send In Weld Testing
    • AWS D1.1 Send in Test Kits
    • Frequently Asked Questions >
      • How much does a welding certification cost?
      • How do I become qualified for bridge work?
      • Does a Welding Certification Expire?
      • What is an ATF Test?
      • What Welding Certification Do I Need?
      • Why Should I Become a Certified Welder?
  • Welding 101 Blog
  • Locations & Contacts
    • Baltimore, MD
    • Beltsville, MD
    • York, PA
    • Scranton, PA
    • Southern MD Welding School
    • Scranton PA Welding School
    • Arnold MD Welding School
  • More...
    • Why Earlbeck >
      • Fabrication Company Case Study
    • History
    • Photo Gallery
    • Resources
    • Testimonials
    • Our Policies

How to Choose Flux for your Soldering or Brazing Application

3/5/2019

7 Comments

 
Soldering Application
Let’s flux about it…
 
You’ve decided to make a repair; you have your soldering gun or brazing torch ready to go, but it hits you! “I don’t have any flux!”
Not to worry, we will help you choose what flux is right for you, but first you will know the difference between the applications.
 
 “What’s the difference between soldering and brazing?”
The American Welding Society (AWS) defines brazing as a process which involves a filler metal that turns to liquid above 842 degrees Fahrenheit (450 degrees Celsius). Brazing applications are a mechanically strong joint. You would typically see this application being used in the automotive industry, for jet engines and in HVAC. You may not know, but your cookware and utensils are also put together using this application. Did you ever wonder how your cookware was so durable? Probably not, but it’s still good to know!

Soldering also involves a filler metal but turns to liquid below 842 degrees Fahrenheit (450 degrees Celsius). This makes the joint electrically strong and can withstand any electric currents running through. If you are soldering any type of electronics, you will need to keep in mind that the temperature needs to stay below 842 degrees Fahrenheit so that your electronics don’t burn up. Yikes! 
Since soldering has a lower processing temperature, the joint is not as strong, compared to the brazing application. This is sometimes the most desirable application, because it has a lower liquidus state compared to brazing.

Of course, always follow your procedure or spec sheet for the proper application for every job!
 
Now we know the difference between the applications, but we need something else to complete the job. “We need flux!”

“What is flux?”
Flux is a chemical cleaning agent, flowing agent, or purifying agent. Flux is used in extracting and joining metals and is crucial to promote melting of the filler metal.
​
“Do I even need flux?”
Yes. It is imperative to use flux for the following reasons:
  1. Removes oxides from metals to be joined (you will still need to clean your metals prior to application).
  2. Prevents oxidation after completion.
  3. Improves “wetting out” characteristics and heat transfer, which allows the filler metal to flow and not ball up.

“What type of flux do I need?”
There are many options available, but they all have their advantages and disadvantages.  You will have to take many variables into consideration, before you grab the nearest flux on the shelf. Not all flux is created equal!
Here are the things you need to know, in order to find the right flux for the job:
  • Application
  • Process
  • Type of metals to be joined
  • Filler metal
  • Thickness
  • Diameter of filler metal
  • Desired appearance/cleanliness
  • Any additional information that is relevant for the job

brazing
​You will have choices when it comes to the type of flux you will need. Here are some types that are out there:
  • Flux coated filler metals
  • Rosin core solders
  • Powder
  • Liquid
  • Paste
  • Gel
  • Flux that is “injected” into the flame from the fuel supply
 
 Solder Fluxes:
No Clean Flux- Residue, if any, is minimal and will “vanish” from the heat produced. If residue needs to be removed, it will require solvent cleaning. It’s very hard to remove and could become an issue because it can interfere with electronics. The residue left behind from the flux is conductive.                  Typical primary ingredient: Isopropanol

Rosin Flux- The reaction between the flux and the metallic oxides on the joint metals make the flux flow easily and provides the cleaning required to “wet” the joint. Rosin flux becomes inert when cooled and solid. If electronics heat up enough to make the residue liquid, the acid can start deteriorating connections. Residue can be removed with alcohol. Typical primary ingredient: Rosin (tree sap)

Water Soluble Flux/Organic- Highly acidic and corrosive. Residue should always be removed when complete. Clean with water, steam, or water-based cleaning product. Typical primary ingredient: Isopropanol
 
Brazing Fluxes: 
General Purpose Powder Flux- Active range 1400-2200 degrees Fahrenheit. Use with low fuming Bronze, Nickel Silver, Copper base alloys, Steel and Cast Iron. This is the same flux that is coated on flux Bronze. Typical primary ingredient: Boric acid, Borax

White Flux- Low temperature (1050-1600 degrees Fahrenheit) silver brazing. This flux is used with most ferrous and non-ferrous metals and not recommended on Aluminum, Magnesium, or Titanium. Typical primary ingredient: Boric acid, potassium fluorohydroborate

Black Flux- High temperature (1050-1800 degrees Fahrenheit) silver brazing. Used on heavy parts where overheating or prolonged heating may occur. This flux is recommended when brazing stainless steels. Residue can be more difficult to remove.
​Typical primary ingredients: Boric acid, potassium fluorohydroborate.

Aluminum Flux- A powdered flux designed for use with aluminum alloys (915-1115 degrees Fahrenheit). You can apply this by sprinkling on dry, mixed with water or alcohol to form a paste. Typical ingredients: potassium chloride, sodium chloride.

Flux Injected in Flame- This flux is introduced into the fuel gas and passed through flame. This increases strength, reduced filler metal consumption, minimal post braze cleaning, quicker braze times, increased penetration, and can cut costs by 40%.
Typical primary ingredient: Trimethyl borate.

Hybrid Fluxes- Some manufacturers have hybrid fluxes available for difficult applications. Brown fluxes have been tested to work like black flux, but easier to remove residue.
 
Although there is no “silver bullet” when choosing the appropriate flux, you may find that multiple types of flux are needed but testing and evaluating may be required for best results. Please contact an Earlbeck Gases & Technologies Representative to help determine the best flux for your job!

Brian Dressel

Account Manager at Earlbeck Gases & Technologies

7 Comments
Patrick Ross link
7/10/2020 09:54:01 am

I like what you said about brazing to make a mechanically strong joint. My sister wants to get a machine built in the coming weeks, and she wants to make sure that it's strong. I'll share this information with her so that she can look into her options for silver brazing services that can help her with this.

Reply
Metal Fabricators Colorado Springs CO link
5/5/2021 05:34:37 am

I enjoyed reading the article above, it really explains everything in detail, the article is very interesting and effective. Thank you and good luck with the upcoming articles.

Reply
Tim link
10/28/2021 10:35:17 am

brazing would be much stronger. Thank you for sharing tschiques.

Reply
paintersinsantaclarita.com link
2/4/2022 05:22:40 am

Thanks for sharing this information. It was very helpful.

Reply
Hire us today! link
2/4/2022 07:32:14 am

Great work. Thank you so much for sharing this information.

Reply
Kenzo Madrigal
7/30/2022 04:17:33 am

Your Article is so good and informative thanks for sharing this content <a href="https://indoorcardiopro.com/cable-upright-row/">cable upright row </a>

Reply
dryer vent cleaning link
8/17/2022 10:03:07 pm

Thank you for the tips and ideas. It was very helpful.

Reply

Your comment will be posted after it is approved.


Leave a Reply.

    Categories

    All
    Case Studies
    Earlbeck News
    Gas Information
    General Welding Knowledge
    Product Feature
    Welding Certification

      Join our mailing list

    Subscribe to Newsletter
    Picture
    Picture
    Picture

    RSS Feed

Baltimore, MD

​8204 Pulaski Hwy
Baltimore, MD 21237

​
Welding Supply & Gas Showroom
Hours: Mon- Fri 7:30 AM - 5PM
Phone: (410) 687-8400
Fax: (410) 687-1394

Welder Training & Testing Center
Phone: (410) 687-8400

    Sign up for our Newsletter

Subscribe to Newsletter

Beltsville, MD

10792 Tucker St
Beltsville, MD 20705
​
Welding Supply & Gas Showroom
Hours: Mon-Fri  7:30AM - 4:30PM
Phone: (301) 937-8884
​Fax: (301) 937-1811

The College of Southern Maryland's Center for Trades and Energy  Training 
6170 Hughesville Station Place
​Hughesville, MD 20637

​
Welder Training & Testing Center
​Phone: (410) 687-8400

York, PA

​95 Aberdeen Rd
York, PA 17406

Welding Supply & Gas Showroom
Hours: Mon-Fri  7:30AM - 4:30PM
Phone: (717) 916-6611
​Fax: (717) 764-1281

Welder Training & Testing Center
​
Phone: (410) 687-8400

AACC Clauson Center for Innovation and Skilled Trades

101 College Parkway
Arnold, MD 21012

​Welder Training & Testing Center
​Phone: (410) 687-8400
​

Scranton, PA

4961 Birney Ave
Scranton, PA 18507

Welding Supply & Gas Showroom
Hours: Mon-Fri 7:30AM - 5:00PM
Phone: (570) 457-8954

Scranton, PA at Johnson College
3427 N Main Ave
Scranton, PA 18508

​
Welder Training & Testing Center
​Phone: (410) 687-8400

  • Products & Services
    • Fronius Welding Products
    • Welding & Cutting Equipment >
      • Free Welding Productivity Analysis
    • Welder Rentals & Repairs
    • Engineering
    • Machine Tools
    • Welding & Cutting Automation
  • Gases
    • Free Gas Application Analysis
    • Industrial & Welding Gases
    • Bulk & Microbulk Gas
    • PurityPlus Specialty Gases
  • Welder Training
    • Program Overview >
      • Fundamentals of Welding
      • Intermediate Welding >
        • Intermediate Stick
        • Intermediate TIG
        • Intermediate MIG >
          • Intermediate GMAW - Aluminum
          • Intermediate FCAW Self Shielded
          • Intermediate GMAW - Stainless Steel
      • Advanced Welding >
        • Advanced Stick
        • Advanced TIG
        • Advanced MIG
      • Welding Basics
      • Custom Classes & Open Practice Time
    • Pricing and Class Schedule
    • How to Register
    • Tour Our Facility
    • Why Earlbeck Technical Center
    • On Site Training
    • Frequently Asked Questions >
      • Are student loans, financial aid, or scholarships available?
      • How long does it take to complete the program?
      • Do you offer job placement?
      • How Much Money does a Welder Make?
      • What is the Job Outlook for Welders?
      • What should I bring for my first day of class?
  • Weld Testing
    • Welder Certification
    • Send In Weld Testing
    • AWS D1.1 Send in Test Kits
    • Frequently Asked Questions >
      • How much does a welding certification cost?
      • How do I become qualified for bridge work?
      • Does a Welding Certification Expire?
      • What is an ATF Test?
      • What Welding Certification Do I Need?
      • Why Should I Become a Certified Welder?
  • Welding 101 Blog
  • Locations & Contacts
    • Baltimore, MD
    • Beltsville, MD
    • York, PA
    • Scranton, PA
    • Southern MD Welding School
    • Scranton PA Welding School
    • Arnold MD Welding School
  • More...
    • Why Earlbeck >
      • Fabrication Company Case Study
    • History
    • Photo Gallery
    • Resources
    • Testimonials
    • Our Policies