How and When to Use Torches, Heat Guns, and Soldering Irons
A little heat burns right through some thorny home fix-up problems. At the low end, 200 to 400 degrees Fahrenheit, heat softens old paint and putty. At the higher end, 400 to 800 degrees, it can thaw frozen locks and rusted nuts and solder electrical and plumbing connections. Still, more firepower, up to 3,000 degrees, will braze metals (a stronger form of soldering that uses harder filler materials) and cut or weld iron and mild steel.
High heat for home use is created with electricity or by igniting a gas such as propane, MAPP (methylacetylene-propadiene), or acetylene, each of which burns hotter than the last. While these gases will burn on their own using the oxygen in the air, to generate the most heat they need to be burned together with pure oxygen from a separate tank.
The important thing is to match a tool’s heat output to the task at hand. A $245 oxy-acetylene torch can weld steel; it can also sweat copper pipes or caramelize, but that would be overkill. For about $50 each, a handheld propane torch and an oxygen-fuel combo if you do a lot of fence or pipe repair should give you the heat you need in a manageable package.
Types of Torches
Oxygen-fuel torch (MAPP or propane)
Good For: Cutting and welding iron and steel, as in fence repairs. These gases don’t make as sharp and efficient a flame as an oxy-acetylene torch.
Good For: Brazing, cutting, and welding iron and steel. Caution: Acetylene is harder to control and more dangerous than other fuels. Visit a welding supply store for the goggles and other protective gear — and welding classes — you’ll need to use it safely.
Pictured: A compact oxy-acetylene combo kit, typical of the way these torches are sold.
Good For: Soldering copper pipes, brazing, and heating frozen pipes and rusted nuts.
Pictured: A torch with an electronic ignition, which is safer and more reliable than a spark, and a flame-spreading tip that lowers the heat for softening paint and caramelizing foods.
Types of Heat Guns and Soldering Irons
Electric heat gun
Good For: Softening old paint, putty, and asphalt tile; heat-shrinking plastic films and electrical tubing; soldering (requires special attachment).
Pictured: A pistol-style gun with variable controls, which is safer than a single-temperature wand-style one.
Electric soldering tools
Good For: Soldering electrical connections.
Pictured: A pencil-style iron and a soldering gun. The iron takes longer to heat up but is less expensive.
The Hot Spots
A torch flame has many parts, all with different temperatures. While different gases produce different flames, the hottest point of any flame is at the tip of the inner cone, where the pale flame meets the deeper-colored outer flame.
How to use torches
|LEVEL||TEMPERATURE||WHAT IT CAN DO|
|LEVEL||TEMPERATURE||WHAT IT CAN DO|
|HOT||200-400 degrees Fahrenheit||Softening paint and putty|
|350-840 degrees Fahrenheit||Soldering: joining metals with a low-temperature metal filler|
|HOTTER||840-1,500 degrees Fahrenheit||Brazing: soldering with hard filler|
|1,300-1,600 degrees Fahrenheit||Cutting steel|
|HOTTEST||1,250-2,800 degrees Fahrenheit||Welding: melting metals (typically aluminum,
iron, or steel) together
Where to Find It
Electric heat gun:
Heavy-duty variable temperature heat gun Model #8977-20
Milwaukee Electric Tool Corporation
Electric soldering tools:
Weller universal multipurpose soldering gun with dual heat (140/100 watts) and Weller 25-watt lighted soldering iron
Cooper Tools, Barrie
Trigger-start cast-aluminum torch head:
Oxygen/ MAPP gas brazing/ welding/ cutting torch kit:
Propane, MAPP, and oxygen all from BernzOmatic.