Hi-Temp Brazing, Inc. FAQs

Dip brazing is the process of joining two or more pieces of metal by flowing a filler metal in between the joint interfaces at a temperature that’s below the melting point of the base metal but above 900 degrees Fahrenheit. After cooling to the solid state, the filler metal creates a strong, metallic bond throughout the newly joined area. 

For aluminum dip brazing, the filler metal is approximately 88% aluminum and 12% silicon. After being chemically treated, the parts are assembled with the filler metal placed as close to the joints as possible. The assembly is then preheated inside an air furnace between 1,000 and 1,050 degrees Fahrenheit to ensure a uniform temperature of masses in the assembly.

Next, the part is immersed in a molten sea bath with salts that are called aluminum brazing flux. The bath is kept at a higher temperature in a salt bath furnace. As the assembly is dipped or immersed, the molten flux comes in contact with all internal and external surfaces at the same time. This liquid heat is uniform and very fast. Since the bath is a flux, complete bonding on oxide-free surfaces yields incredibly high-quality joints. The time of dipping or immersion depends on the product being heated but is rarely over two minutes long.

For the best aluminum brazing results, you should use aluminum compatible with the brazing process. Examples are 6000, 1100, and 3003 series aluminum. Aluminum gives high-quality results. You can also braze other metals such as steel, stainless steel, cast iron, brass, bronze, nickel, and/or copper alloys.

Metals such as gold or silver should not be dip brazed; however, we can torch braze silver and/or gold. These metals require a lot of precision and it’s better if these metals are soldered instead of brazed. Silver and gold can handle the lower heat better and soldering still gives a sufficient bond, even if it’s not as strong as aluminum dip brazing. 

While both are individual metal-joining sheet metal techniques within the overall sheet metal fabrication process, brazing and welding both have different operations. 

Aluminum brazing joins metals by melting and flowing a filler metal into the joint. Welding is a technique that joins metals by melting the base metal and causing fusion. 

For brazing, the filler metal has a lower melting point than the adjoining metal. For welding, the filler metal has a higher melting point. 

Brazing fabricators don’t melt the base metal, but welding fabricators melt the base metal and each workpiece together. 

Brazing uses capillary action and welding uses fusion.

Aluminum vacuum brazing uses a clean vacuum environment without flux. Aluminum dip brazing uses a salt bath flux that breaks down metal oxides and enables a filler metal to diffuse into the base metal. 

During aluminum dip brazing, parts are assembled with the filler metal placed outside of the joint and between surfaces. When heated, the filler metal enters the joint and pushes the flux out of the joint.  

There is also more precision required in machining parts to prepare for vacuum brazing than for flux dip brazing.

Aluminum brazing requires relatively lower temperatures when compared to welding. Welding is readily automated and can join dissimilar metals.  Welded joints are usually as strong or stronger than the base materials. Brazing is different from welding in that the temperature is significantly lower and doesn’t melt the base metals.

It depends on the size and complexity of your order. We can fulfill smaller orders in as little as a week or so. If it’s a much larger and more complex order, the aluminum brazing process can take a few more weeks, depending on the part.  

We also ship out our finished products every day. If you need express shipping, we can expedite that for you as well. 

For starters, we are highly specialized professionals in aluminum dip brazing. Other than some light welding work and a little torch brazing, we don’t do anything else and have been doing this since 1973.  

We’re one of a very select group of dip brazers who have Nadcap accreditation to perform this process for worldwide prime contractors, their suppliers, military organizations, and other large organizations. We’ve also dip brazed almost everything, ranging from the aviation/aircraft industry to the medical device industry, and more. 

Just like the finished products we produce, we believe in top-quality customer service and value our customers with the utmost courtesy and professionalism. Without you, we wouldn’t be here! Our 19,200 square foot facility provides a very safe environment for our workers to complete your jobs, and the room to house all of the equipment we invested in to produce the high-quality products that are sent back to every one of our customers every day.  

When we say we’re family-owned and operated, we mean it, working side by side with each other every day in the office. We value the relationships we've formed with our customers throughout all of these years and welcome the opportunity to provide even more top-quality work for our new customers that we gain along the way. We appreciate you all and truly love what we do here!