What kind of glue is used to attach a rearview mirror?
3 Answers
If the rearview mirror in your car falls off, you can use special rearview mirror adhesive to reattach it, such as AB glue, glass glue, strong double-sided tape, or mirror base glue, which is specifically designed for automotive glass rearview mirrors. Alternatively, you can use UV glue. Rearview mirrors are divided into internal and external types, and the detachment points vary. If the interior rearview mirror detaches from the windshield joint, high-strength transparent adhesive should be used, which can be found at 4S shops or glass repair shops. However, if the adjustment ball joint of the rearview mirror or the lens or housing of the external rearview mirror falls off, it needs to be replaced promptly. Commonly used AB glue for rearview mirrors on the market consists of two components, A and B, which must be mixed before use. Some types of AB glue take a long time to fully cure. If the mirror cannot be reattached with glue, a suction cup rearview mirror can be used. This type does not require adhesive on the back of the mirror; it simply uses a suction cup to attach to the glass. Glass glue is a material used to bond and seal various types of glass to other substrates. It is mainly divided into two categories: silicone glue and polyurethane glue (PU). Silicone sealant, commonly referred to as glass glue, comes in acidic and neutral varieties. Neutral glue is further categorized into stone sealant, mildew-resistant sealant, fireproof sealant, and pipe sealant. Strong double-sided tape can also be used. There is specialized double-sided tape for rearview mirrors, which only requires peeling off the protective paper on both sides. However, it is essential to remove any residual adhesive from the rearview mirror first. Additionally, if you plan to hang objects, make sure to check the weight capacity of the tape; otherwise, it may fall off again soon. UV glue, also known as photosensitive adhesive or ultraviolet curing adhesive, is a type of adhesive that only cures under ultraviolet light exposure. It can be used as a bonding agent or as a base for paints, coatings, and inks. "UV" stands for ultraviolet rays. Ultraviolet (UV) light is invisible to the naked eye and is a segment of electromagnetic radiation beyond visible light, with wavelengths ranging from 10 to 400 nm. The curing principle of UV glue involves photoinitiators (or photosensitizers) in the UV-curable material absorbing UV light to generate active free radicals or cations, triggering polymerization and cross-linking reactions. This transforms the adhesive from liquid to solid within seconds. During the application process, UV glue must be exposed to UV light to cure. This means the photosensitizer in the glue reacts with monomers upon UV exposure. Theoretically, without UV light, the glue will not cure. The function of a rearview mirror is to reflect the conditions behind, beside, and below the vehicle, expanding the driver's field of vision and reducing the likelihood of safety incidents. Rearview mirrors are categorized by installation location: interior rearview mirror, exterior rearview mirror, and under-mirror.
Last month, I just glued a rearview mirror myself using automotive-grade double-sided tape, like the 3M VHB series. That stuff is super sturdy and heat-resistant. Cleaning the glass is crucial—you need to wipe off dust and grease with alcohol swabs to ensure the surface is clean and dry before applying the tape. Then, align the position, press firmly for a few minutes to get an initial bond, and it’ll fully set after a day. The advantage of double-sided tape is that it’s cheap and simple, even DIY beginners can handle it, unlike regular glue that might corrode the glass or leave marks. After sticking it, check it periodically—if it loosens over time, just clean and reapply it to avoid spending money at the repair shop. Remember, don’t cheap out with off-brand glue; if it falls off while driving, it’s seriously dangerous—safety first.
With years of experience in auto repair, I often recommend professional adhesive tape for reattaching rearview mirrors because it's specifically designed to resist vibration and aging. Before installation, thoroughly clean the windshield with anhydrous alcohol to remove any stains, then apply the heavy-duty double-sided tape and press the mirror base firmly into alignment. Ordinary glue like 502 is too brittle—it tends to crack and fall off due to winter contraction or summer heat, and can damage the glass. For different vehicle models, choose weather-resistant brands like 3M, which suits most cars. Daily driving should avoid strong impacts on the mirror to extend its lifespan. Address issues promptly to prevent accidents while driving.
