When, how, and why to use a heat gun.

The heat gun- a technician’s indispensable friend.

Questions about using a heat gun during phone repair come up often. In most cases it is because someone watched a video tutorial and has little or no experience with this tool. Often they will ask whether or not a blow dryer can be used in it’s place. In some cases the answer is yes but it will take much longer. Let’s take a look at why heat is necessary in the first place.

The adhesive inside of your phone can be very strong. From one manufacturer to the next you will see varying degrees of stickiness and the same is true from one component to another. In some cases you can get away without using heat while in others it is absolutely necessary. As a general rule of thumb the amount of heat needed does not vary all that much.

How hot should my heat gun be?

heat gun
Preparing a Galaxy S5 for screen removal.

For most modular component removals we work with a relatively low temperature. At about 100 degrees Fahrenheit the adhesive on any phone becomes much more pliable than at normal room temperature. You can also rest assured that your phone will not be damaged at this level since we often subject them to higher temperatures for extended time periods on a hot summer day. The next question of course is how to tell if you have reached the desired temperature. While you can use a special tool designed to determine the temperature of the surface you are working with this is not really required in most situations. Here’s what we do for routine heating of just about any adhesive underneath a flex cable, battery, lens, or modular SIM/micro SD card reader.

Hold the phone in your hand.

Aim the heat gun at the area you want to heat but in a way that your hand is getting the same amount of heat as the phone.

Slowly heat the surface with your gun set to low at about eight to ten inches from the phone.

When your hand starts getting almost uncomfortably warm you will have reached sufficient temperature to make the adhesive pliable enough to work with.

If you didn’t burn your hand then you haven’t harmed the phone.

If the surface cools down you can repeat the steps above until the part has been removed.

heat gun iphone 4s
Heating the iPhone 4S proximity sensor foam.

heat gun lg g3 battery
The LG G3 battery has a very strong adhesive beneath it.

If you are dealing with a component that can easily shift during normal use it is very important to prevent this from happening. A perfect example is the vibrator motor inside of your phone. This component is a simple electric motor with an uneven weight attached to it. As the motor spins the weight wobbles back and forth causing a vibrating effect. Imagine a car that isn’t firing on all cylinders. This uneven distribution of energy creates the same result and you can feel the vibration throughout the vehicle. This vibration is a great way to make the screws inside of your phone unwind themselves. Because of this problem most manufacturers have switched over to using adhesive to secure the motor instead of, or in addition to screws.


LG g3 charging port
LG G3 charging port removal.

Besides the vibrator motor working screws loose there are other internals of your phone that need to be secured in place. One of them is the battery. In some cases manufacturers use a very sticky adhesive between the cell phones battery and the mid-frame. Phones like the LG G3, iPhones 5C and 5S can be very stubborn when it comes to battery removal. The adhesive on these models is so strong that you run a risk of damaging your battery during the removal process. Hopefully if you are removing the battery it is because you are installing a new one. Even so it is probably never a good idea to puncture a Lithium Ion battery if you can prevent it. When batteries leak gases they release a very distinctive odor. It smells like an overly sweetened cheap perfume. If you notice this you will probably want to put the battery in a zip lock bag and take it to a recycling center. Always be sure to dispose of old batteries at a proper disposal center. Anything that you throw into the trash can eventually end up in a land fill and chemical inside of old batteries may leak into the ground water below. Not a very appetizing thought.

Heat guns have many uses outside of cell phone repair so for most DIYers and people in the appliance repair business it is a must have. Fortunately a heat gun is an inexpensive investment that should last you a very long time.


7 Comments on “When, how, and why to use a heat gun.

  1. Hi there. Great site. Thanks for sharing all this info. Do you have a link for a heat gun that can be set to 100°f ?

  2. I don’t have anything as far as setting a heat gun to that specific temperature. It might be easier to use a laser or IR thermometer to keep track of surface temperature. Most heat guns will be higher than 100 degrees F. At that range a hair dryer might even be a better option.

  3. I tried using a hairdryer and replaced the battery in my Galaxy s6. When I reassembled it, the screen was dead. I replaced the original battery and the screen was still dead. It would vibrate and chime when I powered it up, but the screen was dead. Then in going back and forth with the different batteries, I screwed up the battery connector on the motherboard. Now I am trying to decide if it is worth it to by a new mother board and display and try again.Any thoughts?

    1. Between a replacement motherboard and the display you’ll probably end up close to the phones total value. At the moment I have and S6 with a broken screen that I haven’t fixed for the same reason. At three generations behind it’s hard to justify the cost of an OLED display.

Comments are closed.