Heat Guns & Their Uses

Modern electric multi-purpose heat guns have now pretty much replaced the seemingly old-fashioned paraffin and bottled gas blow lamps and torches. In the good old days, their uses were limited to stripping paint from your front door or for felt roofing repairs. Although they still have their uses, they are generally left to gather dust in sheds and garages. They have been replaced with modern electric heat guns that come supplied with various attachments and have variable heat settings and adjustments. The features on the modern equipment make these kits far more attractive to users, as the range of jobs for which they can be used is large. The hot air flow produced by a heat gun is less dangerous than a naked flame, but it can still cause flammable materials and other items to catch fire or crack, cause injury if directed onto skin or shatter glass. One great advantage is that the heat is almost instantaneous so the heat gun can be switched off during pauses in the work. The flame blowlamps, on the other hand, have the inconvenience of needing to be relit if the flame is extinguished.

HEAT GUN USES:

• • Paint stripping — The heated air is directed onto the painted surface, causing it to soften so that it can be easily stripped off with a stripping knife or hook. For best results, it is best to work up the surface with the heat gun above the stripping tool, softening the paint just before the stripping tool reaches it.
• • Drying paint or varnish — Use heat settings between 86° to 266°F (30° to 130°C). Care must be taken when using a heat gun to prevent dust particles from blowing onto the paint/varnish.
• • Applying heat shrink — Protect and finish wires of all types with heatshrink. The temperature range to shrink general purpose heat shrink varies from 194° to 239°F (or 90° to 115°C).
• • Drying out damp wood (before filling or painting) —212° to 392°F (100° to 200°C).
• • Softening adhesive (such as when applying worktop edge trim or lifting floor tiles) —572° to 752°F (300° to 400°C)
• • Forming and shaping plastic pipes — From 392° to 572°F (200° to 300°C).
• • Heat-shrinking plastic film — Between 392° and 572°F (200° to 300°C).
• • Welding some plastics — Set between 626°and 752° F (330° to 400°C).
• • Soldering plumbing joints
• • Loosening rusty nuts and bolts

All these processes can be performed using the heat gun, but please read and follow manufacturer instructions and guidebooks first.

HEAT GUN FEATURES:

• • Wattage — Commonly from 1,000W to 2,000W (a measure of the power of the gun). Provided that there are heat and/or airflow controls, the higher the wattage, the better.
• • Main control switch — Usually mounted on the front of the pistol grip and normally a “dead man” switch so that power is switched off when the finger pressure is removed — an ideal safety feature as the heat gun stops if it is accidentally dropped.
• • Temperature setting — At least 932°F (500°C) is needed for stripping paint — the lower the bottom end of the range, the more useful the heat gun.
• • Airflow setting — Having variable or more than one speed makes the tool more versatile.
• • Thermal cut out — This will switch off the tool if it becomes overheated. If this occurs, it indicates a fault in the tool or method of use. For safety, the fault must be identified and corrected before the heat gun is again used.
• • Flex length — Lengths of 6 to 9 feet are generally fitted, which means that when using an extension lead, the tool can be used at the full reach without having the socket hanging in midair.
• • Surface stand — This enables the heat gun to be safety “rested” during pauses in the work and after each use. This allows it to cool down before it is safely stowed away. It also allows the gun to be used “hands-free” when two hands are required on the work piece (such as when bending a plastic pipe).
• • Nozzles and attachments — Most heat guns have a range of nozzles that can be fitted for specific uses.

SAFETY WITH HEAT GUNS:

• • Heat guns consume up to 2,000 Watts, so when an extension lead is necessary, only use a lead that is correctly rated. Always completely unwind the lead.
• • Never obstruct or cover the air inlet grills. If the air flow is restricted, the heat gun will overheat, which can potentially make it flammable.
• • Never operate the heat gun with the outlet nozzle hard up against a surface; this will restrict the air, which can have the same effect as obstructing the air inlet grills.
• • Do not use a heat gun near flammable materials.
• • Always switch the tool off before putting it down on any surface.
• • Always allow the tool to cool before storing away.
• • Do not place the nozzle next to anything while it is hot.
• • Never touch the hot metal nozzle to clothing or skin.
• • Do not use for stripping lead-based paints.
• • Do not allow any paint to stick to the nozzle — and if some paint does stick, allow the gun to cool down and remove the paint.
• • Do not look down the nozzle while the gun is turned on.
• • Do not insert anything down the nozzle of the gun.
• • Always check your equipment for damaged leads and other hazards.

ATTACHMENTS AND ACCESSORIES:

• • Reducer nozzle — Use when you want to concentrate the heat onto a specific area.
• • Reflector nozzle — Wraps around a plastic or copper pipe to spread the heat around the pipe surface.
• • Flat nozzle — Used for spreading the hot air over a wider narrower area.
• • Glass protector nozzle — For use when stripping paint on a window, to keep the direct heat off the glass.