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If you ask anyone who’s accustomed to using heat for joining metals what their favourite fusing process is, most will probably say brazing.
While welding calls for extreme temperatures to melt fillers and base metals, and can be outright problematic when fusing dissimilar metals, brazing only requires the capillary action of a melted filler to join almost any type of metal. And because brazing doesn’t need the high flame temperatures that are common with welding gases like acetylene, it allows for the use of safer, less reactive fuel gases like LPG.
LPG is one of the most efficient gases in the world, and with its clean-burning, non-oxidizing characteristics, it’s also the ideal fuel source for brazing metal. You need to have special torches, auto ignition devices, and regulators to braze with LPG, though; so let’s take a look at some of the tools that are available that can help you with your brazing, and some other projects too.
The Benefits of LPG Metal Brazing
Regardless of whether you’re an HVAC expert who regularly works with thick copper tubing, or a car enthusiast repairing delicate aluminium panels, brazing’s non-destructive nature means that there’ll never be a shortage of jobs that wouldn’t be the perfect fusing method. To get the most benefit from it though, you need to have a durable, high-pressure LPG brazing kit that can generate temperatures high enough to work with a full assortment of filler materials quickly and under all conditions.
Next to knowing the melting temperature of your base metal, torch flame temperatures are the most important aspect of brazing. High-quality LPG brazing torches are capable of delivering temperatures between 950°C and 1200°C: the ideal range for working with most silver, copper, and zinc fillers. And with temperatures this high, you’re also able to create higher-strength joints easier through preheating.
When compared with oxy-acetylene welding, or even combined LPG gas welding kits, LPG brazing torch kits feature a host of operational benefits that include:
· Significantly lowest equipment, consumable, and fuel costs;
· The highest caloric value from lower processing temperatures;
· Considerably less difficulty with joining dissimilar types of base metals;
· No potential risk of base metal warpage, heat stress, or burn-through.
· An absence of working temperatures that could pose a secondary fire hazard; and,
In short, LPG’s flexibility is a perfect fit for brazing’s special attributes, and it’s not hard to see how much value is packed into one of these ruggedly uncomplicated setups.
Keeping Brazing Kit Components Simple
Possibly the most obvious detail about even the heaviest-duty brazing kits is how portable they are. And the fact that they can be used with any sized LPG bottle with a standard 5/8″ connection highlights their simple makeup, which consists of:
· An LPG torch. Weighing only 300kg and producing 4 bar pressure, a lever-activated, automatic ignition brazing torch with a swivelling inlet connection is easy to use with one hand, even in windy conditions.
· An LPG regulator. With a maximum input pressure of 20 bar, and a maximum preset output pressure of 4 bar, a brass LPG regulator with an operating temperature range of -20°C to 50°C is simple that designed for severe use.
· LPG hose. A high-pressure, EPDM rubber hose with synthetic reinforcement is the standard hose for use with all LPG gas bottles, and is manufactured to BS3212/2 standards.
Unlike even simplified welding setups, LPG gas kits for brazing don’t require a collection of fuel, oxidizer, and torch components, or lengthy learning curves for operators to learn how to set the equipment up. The techniques need to become proficient at brazing are acquired almost immediately, and that’s a major advantage when it comes to fusing activities.
Strength and Versatility with Metal Brazing
Although the cost, convenience, and ease of use of LPG brazing typically come to the forefront of how valuable the process is, it’s impossible to overlook just how effective the process is.
For any situation where metals need to be joined and neither a mechanical nor semi-permanent solution is sufficient, the strength and versatility that comes with LPG brazing allow you to create expert joints that are:
· Conducive with both high and low-volume fusing processes;
· 5 times stronger than joints made using solder fillings; and,
· Capable of withstanding severe shocks and shear forces.
In fact, with properly cleaned base metals, and ample preheating and filler application with the correct-sized torch burner, the tensile strength of most brazed joints can significantly exceed the strength of the base metals themselves.
Brazing Burner Tips Make the Difference
With brazing kits and torches suitable for everything from installing gas and water pipes, to bending tubes and making jewellery, you always want to remember that their suitability for such a broad range of tasks comes down to the types of burners they use.
Burners are the fine-tuning tips that determine the size and characteristics of the flame coming from the brazing torch. And depending upon the type of brazing that needs to be done, you can find burners with diameters and jet sizes that are designed for a full selection of flame aspects, including:
· General purpose flames;
· Well-defined flames;
· Small, narrow flames;
· Powerful, wide-angled flames; and,
· Soft, diffused flames.
You can even find burners and burner attachments for a host of tasks that you might normally associate with LPG torches, including:
· Weed burning. Passing a torch and burner over unwanted weed growth provides an environmentally friendly way of permanently removing them from between driveway slabs and pavers.
· Shrink wrapping. Specially fitted torches and burners are excellent for use to heat seal polyethylene covers and construction shrink wrap around machinery and even scaffolding.
· Paint stripping. With a fishtail attachment fitted to a standard burner, you can instantly turn an LPG torch into an easy-to-control paint-stripping tool or wood, metal, or stonework.
Suffice it to say, it’s the burner tips that make the difference in how flexible your brazing torch is capable of being. And you’ll be surprised by just how many jobs your brazing kit can do only by having a good selection of burners.
The Final Word
At the end of the day, while there’s no shortage of processes available that use heat to join metal, no single process is capable of doing everything. Brazing, however, is the one process that manages to combine economy and efficiency almost perfectly; and it does so with safety that’s unparalleled when using any type of fuel gas.
If you haven’t considered investing in a high-pressure LPG brazing kit for either your home or business, now’s the time to do it. Regardless of whether you’re a beginner or you’ve been working with hot metal for a long time, you’re going to quickly appreciate how much you can accomplish with brazing.
