Question: What is the difference between the fluoride-free brazing flux and the standard brazing fluxes?

The fluoride free brazing flux is formulated with no fluoride in its composition. Traditional brazing fluxes are formulated containing different chemicals with fluorides that are active oxide removers from the metal surfaces and allow the filler metals to flow efficiently and consistently.

The fluoride-free flux uses a different approach to remove oxides from the base metals and allow filler metals to flow.


Question: We have been using traditional brazing fluxes successfully for many years. What is the advantage of a fluoride-free flux?

Fluoride-free fluxes have been requested by many people, for many years. There are a number of reasons companies and people have been interested in making this change:

Health and Safety. The brazing fluxes that have been used since time immemorial have been fluoride containing. As a result, during the heating process, an HF (hydrogen fluoride) gas has been yielded during the brazing process. Any intake of this HF gas is extremely dangerous and unhealthy

Another aspect of health and safety is skin related. Through the years, it has been a given that the brazing flux would dry out skin on the hands and cause small cuts by the fingernails to grow larger and last for a week or so. Gloves were always an option, but given the precision required for flux application, they were not always worn.

Fluoride-free flux is not aggressive against skin and will not cause the same type of epidermalogical reaction that traditional brazing fluxes have caused.

Environmental: When dealing in brazing applications, all post-braze residues need to be washed with water. Although fluoride is added to water in many states to help strengthen teeth, it is not an item that can be dumped down the drain to be filtered and recycled.

Additionally, as mentioned in reference to the HF gas, ventilation requirements are driven by filtering of air that is expelled from the plant. If the HF gas is removed, the air being ventilated from a plant will be cleaner and less harmful.


Question: What is the disadvantage of a fluoride-free flux?

As in any change one makes from what they are used to using, there are disadvantages. The fluoride-free flux is in many ways a drop-in replacement, but does have a tighter process window than the fluxes it can replace.

This is similar to the electronics industry when manufacturing switched from the wide-window of rosin fluxes, to the narrow window of low-solids, No-Clean fluxes. It may take some time to work out the kinks, but once the process window has been defined, the manufacturing process can proceed to meet the high volume, low defect rate assembly required.


Question: If this has been the type of flux people have wanted for so many years, why is it now being introduced?

Like many things that people want, it is easier to describe what is wanted then to make it. Many years of research and development have been dedicated to finding a flux that meets this type of a chemical composition. After all of the different approaches and techniques used for solving this problem, the research has led to a fluoride-free flux that works on a consistent basis and meets the quality levels required by manufacturer and end-users alike.


Question: I am going under the assumption that is flux will cost more than the flux I am currently using. How will it save me money?

Answer: Many savings are as described with regards to the health, safety, and environment.

Water Filtration: It is recommended that post-braze residue containing water be filtered. However, the waters used to clean the post-braze residues of a fluoride-free flux will not contain the chemical that requires monitoring and filtration of the water – fluoride. This should make the water easier to filter and require less costly filtration techniques.

Air Filtration: By removing fluoride from the brazing process, there is no boron-trifluoride or hydrogen-fluoride gas emitted into the air above or surrounding the process manufacturing site.

Dermatalogical Safety: By removing a corrosive chemistry from the manufacturing site that may come in contact with skin, the fluoride-free flux gives operators a chance, for the first time, to work with a chemical that will not eat skin or etch the areas around the fingernail.

Shipping: If the current product being used is a hazardous product, the shipping class rating is higher (Class 70 versus class 55) and more expensive. If ground shipping small packages, UPS adds $17.00/package for handling.

Consult your insurance provider for details regarding your coverage costs for a product that is safe dermatologically, non-hazardous in gas-emissions, and helps promote a safer environment.