How to glue the back cover on Xiaomi Mi 8: full instructions with photos and videos

Xiaomi Mi 8 is one of the most popular flagships of the brand, but over time, the back cover can peel off, crack or require replacement after repair. If you encounter this problem, do not rush to contact the service center: you can glue the lid yourself, saving up to 3000 rubles. In this article, we will analyze all the stages of the process from the selection of glue to the final sealing, and also tell you how to avoid typical errors that lead to re-unclogging or dust falling under the body.

The main challenge with the Mi 8 is the combination of a glass back and a metal frame. Incorrect adhesive or careless surface preparation can cause the lid to start playing when pressed or fall off after a week. We tested 5 adhesives and 3 preparation methods to choose the best option for home repairs. At the end of this article, you will find an FAQ with answers to frequent questions and adhesive comparison table.

Why the back cover on Xiaomi Mi 8 is peeling off: the main reasons

Before you start repairing, it's important to understand why the lid has moved, which will help you choose the right fixing method and avoid recurring problems.

• 🔋 Battery overheating: When used intensively or charged with Quick Charge 4+, the inside temperature of the enclosure can exceed 50°C, which destroys the factory adhesive.
• 💧 Moisture intrusion. Even if the phone hasn't sunk, high humidity (like in the bathroom) softens the adhesive layer over time.
• 🛠️ Previous repair: If the lid has already been removed (for example, to replace the battery), there is a high risk that the master used poor-quality glue or did not clean the surface of the old layer.
• ⚡ Hits and falls: Mechanical damage disrupts the integrity of the adhesive joint, especially in the corners of the body.
• ⏳ Natural aging: Factory adhesives based on B-7000 or similar compounds lose their properties after 3-4 years of use.

In 80% of cases, the problem is solved by re-adhesive, but if the lid is cracked or deformed, you will need to replace. For the Xiaomi Mi 8, original parts with the article MDY-08-15 (black) or MDY-08-16 (white / blue) are suitable. The cost of a new cover is from 1200 to 2500 rubles depending on the color and supplier.

⚠️ Warning: If the lid has moved away after the phone falls into the water, make sure to check the NFC- antennas and cameras before sticking, and moisture could damage the flexible plumes, and it will cost more to replace them than it would to repair the lid.

What glue to choose for Xiaomi Mi 8: comparison of the 5 best options

The choice of adhesive is responsible for 90% of the success. For the Mi 8, universal compounds like "Moment" or PVA are categorically not suitable - they either will not provide sufficient fixation or damage the plastic elements of the body. We tested 5 specialized adhesives and made a table of their characteristics:

For the Xiaomi Mi 8, the best choice is the B-7000 glue, which provides a strong but elastic connection that does not break down when heated and withstands repeated bends of the body. LOCA is suitable if you have a UV lamp, but it is harder to apply evenly. 3M VHB double-sided tape can be used as a temporary solution, but it is worse seals the joints.

Where to buy glue:

• The 🛒 AliExpress is the cheapest option (from 80 ₽ per 10 g), but delivery takes 2-4 weeks.
• 🏬 Radio stores (e.g. Chip & Deep) are higher (200–300₽) but can be picked up immediately.
• 🌐 Ozon/Wildberries is the average price (150–250₽), delivery 2–5 days.

⚠️ Warning: Don't buy glue in spontaneous markets or from untested sellers. Counterfeiting under B-7000 often contains aggressive solvents that can damage the oleophobic screen covering or antenna modules.

Preparing the phone: what to do before gluing

Incorrect preparation is the main reason why the lid is unstuck again.

Remove old glue from the body and cover|Clean the surface with alcohol (90%+) orcetone|Check the integrity of the sealing rubber bands (if any)|Turn off the phone and remove it SIM-map|Apply the glue with a thin layer (0.3–0.5 mm)-->

Let's take a closer look at each item:

1. Removing old glue. Use a plastic mediator or a wooden stick to scrape the residue neatly. Isopropyl alcohol (99%) is good for hard-to-reach areas. Don't use metal tools, they can scratch the aluminum frame.
2. Surface cleaning: Wipe both surfaces (body and inside of the lid) with a lilac-free napkin dipped in alcohol, and you can use an anti-silicone wipe (sold in auto-chemistry stores) to degrease.
3. Seal check. In the Mi 8, there are thin rubber pads around the camera and connectors. If they are damaged, replace them (Article XM-8-GASKET).
4. Test fit. Before applying the glue, apply the lid to the case and check if there are gaps. If the lid is walking, perhaps the metal frame is deformed, in which case you should contact the service.

If you replace the lid with a new one, look at the antenna hole, which is covered with a special mesh in the original parts that should not be closed with glue, and in cheap replicas, this hole may not be present, which will degrade the Wi-Fi and NFC signal.

💡

If the glue hits the speaker or microphone, don't try to scrape it off with a knife. Use a toothpick dipped in alcohol and gently remove the excess as you move from center to edge.

Step-by-step: how to glue the lid on Xiaomi Mi 8

Now, let's get to the process. You're going to need to:

• 🔧 Plastic mediator or credit card
• 🧴 Glue (B-7000 or analogue)
• 🧻 Wormless wipes and alcohol
• 📏 Paint Scotch (for fixation)
• 🔦 Fen (optional, to accelerate drying)

Step 1. Applying glue

Take the glue and squeeze it with a thin snake around the perimeter of the body, retreating 2-3 mm from the edges. Don't apply the glue with a solid layer, it will lead to overuse and can clog the speakers. For the Mi 8, 1.5-2 g of glue is enough. Pay special attention to the corners and areas around the camera, here the load on the connection is maximum.

Step 2. Fixing the lid

Carefully apply the lid to the body, starting at the bottom (where the USB-C connector is). Press it evenly, avoiding displacement. For reliability, wrap the phone around the perimeter with paint tape, this will prevent shifts during drying.

Step 3. Drying

Leave the phone dry at room temperature for 4-6 hours. You can use a hair dryer (warm air mode, temperature no higher than 50°C) to speed up the process, but don't direct the flow directly to the lid, it can cause bubbles. After 2 hours, check if there are any gaps left. If the lid is "sucked" when pressed, then the glue has not hardened yet.

Step 4 Final check

After drying, remove the scotch and check:

• 🔊 Performance of speakers (whether the sound is muted)
• 📶 Wi-Fi signal quality and 4G (antennae should not be shielded).
• 🔋 Battery heating (if the phone is warmer than usual, the glue could get to the charging controller).

Frequent Mistakes and How to Avoid Them

Even experienced craftsmen sometimes make mistakes that lead to re-repair, and here are the most common ones:

1. Using superglue (cyanoacrylate) to create a rigid compound that cracks when the body is bending, the Mi 8 needs a flexible adhesive.
2. Applying glue to dusty surfaces. Even microparticles of dust reduce adhesion by 30 to 40 percent. Always clean surfaces in a clean, well-lit place.
3. Overheating when drying. If you use a dryer at maximum temperature, the glue can boil and lose elasticity. The optimum temperature is up to 50°C.
4. Ignoring antenna inspection. If the glue hits the NFC or Wi-Fi contacts, the signal will deteriorate. Always test the phone after repair.
5. Savings on glue: Too thin a layer will not seal, and too thick will squeeze into the body and can block the buttons.

Another typical problem is getting glue on the screen. If that happens, don't rub the surface! Let the glue dry, then carefully remove it with a plastic scraper, preheating the screen with a hairdryer (temperature no higher than 40°C). For the Mi 8 oleophobic coating, aggressive solvents are not suitable - they can leave stains.

⚠️ Warning: If the phone stopped charging after you glued it, check if the contacts have been glued to USB-C. Use isopropyl alcohol and a toothpick to clean. Do not insert the charger until the contacts are completely dry!

Alternative methods of fixing: when the glue does not fit

In some cases, the glue can't provide a reliable fixation, for example, if the lid is cracked or deformed and there's no new part available.

• 🧲 Magnetic fixation: Neodymium magnets (3-5 mm diameter) are glued into the phone body and metal plates are attached to the lid. Minus: the signal NFC is deteriorating and the compass may be affected.
• 📎 Clip latches: Online stores sell plastic clip kits that are attached to double-sided tape, suitable for temporary repairs, but not sealing the case.
• 🔧 Mechanical fastener: In extreme cases, you can drill holes in the corners of the lid and the hull, and then connect them with M1.5 screws. Risky method requires precision and can damage the board.

For the Xiaomi Mi 8, we recommend a magnetic method, unless you plan to use contactless payment, magnets are attached to the glue inside the case (for example, next to the battery), and metal washers are glued to the lid. The main thing is not to overdo it with the strength of the magnets, otherwise they can affect the operation of the gyroscope.

If you're going to use mechanical fasteners, use nylon screws -- they don't conduct electricity, they won't damage the board in casual contact -- drill the holes with a drill at minimum speed, and then stick paint tape on the lid to avoid chipping glass.

💡

The best alternative method for the Xiaomi Mi 8 is magnetic fixation with neodymium magnets of 3×1 mm. It does not require modification of the body and allows you to easily remove the cover if necessary.

How to prolong the life of the back cover after repair

To prevent the lid from peeling off again, follow these recommendations:

• 🔥 Avoid overheating. Do not leave your phone in the sun or near heat sources (e.g., on a car torpedo in summer).
• 💦 Do not use your phone in high humidity (bathroom, pools) if the lid is wet, dry it with a dryer in cold air mode.
• 📦 When transporting, put the phone in a hard-walled case, which will protect the lid from impact and deformation.
• 🔋 Try not to use fast charging all the time. Overheating the battery accelerates the destruction of the adhesive.
• 🧼 Every 2-3 months, wipe the joints of the lid with an alcohol towel, which will remove dirt and sweat that can soften the glue.

If you drop your phone a lot, consider a high impact case that covers the ends of the lid. For example, Spigen or Ringke models have reinforced bumpers that take on some of the load when falling. For the Mi 8, a case labeled Xiaomi Mi 8 Case (Tough Armor) is suitable.

And you can also look at the back film, which not only protects against scratches, but also creates an additional barrier to moisture, and Olixar or Skinomi films are hydrophobic and cost 300 rubles.

FAQ: Answers to Frequent Questions