There is a great debate in online forums about whether a heat gun or lighter is the better tool to effectively shrink heat shrink. Some have suggested casual DIYers do not need to invest in a heat gun but use a lighter — or even other common heating elements like a hair dryer, candle, hot glue gun, or soldering iron. But experts say heat guns are truly the most effective and safest way to evenly shrink heat shrink.

Many video tutorials and online forums with photos demonstrate how to shrink heat shrink using either a cigarette lighter or cigar butane lighter. An influencer in this type of video typically moves the lighter’s flame along the harness to shrink heatshrink into place. In these demonstrations, they often hold a disposable cigarette lighter closer to the harness than they do when using a butane lighter, because of that lighter’s greater intensity.

A few videos show other heating methods like running the tip of a hot glue gun or soldering iron along the tubing.

Some experts suggest novices should instead use a hair dryer on the highest setting to apply heatshrink, because it still does not become as hot as a heat gun, lighter, or similar tool. They advocate for this hair dryer method, because it theoretically puts newbies at lower risk of burning the tubing or wires.

This begs the question: are there any benefits with using a lighter to apply heat shrink?  Some people prefer a lighter for its smaller size and portability — both helpful qualities for on-the-go applications. They find a cigarette lighter is easier on the budget and for use in tight spaces, with lighters considered a source of instant heat that facilitates quick repairs.

But other problems can arise when using a lighter on heatshrink. A lighter doesn’t heat as consistently as a heat gun, which could risk burning, scorching, or deterioration of the tubing. The person operating the lighter might get burned just as easily. Lighters may cause combustion in tighter spaces if there are flammable surfaces or accumulated gases from inadequate ventilation.

A heat gun is considered a better choice than a lighter because it warms up and shrinks the material faster, with heat evenly controlled for a uniform application. There are temperature settings on a heat gun that make it safer than a cigarette lighter, with it emanating warmth rather than an open flame,  which may damage material. The consistent production of controlled hot air in a heat gun shrinks tubing precisely and effectively, additionally safeguarding electronics and wires.

Heat gun use comes with rare downsides, such as overheating if the tool runs for an extensive period at high temperatures. Heat gun malfunction is also typically uncommon, leading to overheating — or no heating at all. A glitchy heat gun might spark, potentially igniting dust, debris, and other materials.

No matter the heating method used for applying heat shrink, one should always keep a fire extinguisher nearby.

Prior to any heatshrink application, it is important to first choose the correct shrink ratio, and inspect tubing for damage or defects. It is essential to read all manufacturer’s instructions for operating the heat gun before use. The workspace should additionally be well-ventilated, with flammable materials out of the way.

A person operating a heat gun needs to always wear protective gear, including safety glasses, and heat-resistant gloves.

When the application is complete, it is essential to turn off and unplug a heat gun, then allow the shrink tubing to cool before handling it. After the heat gun has fully cooled down, it should be out of a child’s reach, and stored far from flammable items.