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Dash cams and phone mounts are commonly mounted to the inside of your vehicle using suction cup mounts to the windshield. As long as you’ve properly cleaned the surface that you’re suctioning to, it should hold your dash cam or smartphone, right? I’ve found that unless the suction cup that you have already has an adhesive applied to the suction cup, it may have trouble sticking to your windshield or any other flat surface inside your vehicle. This especially holds true if you live in a climate where it gets very hot, or where the temperature changes significantly.
If you are having trouble with getting your dash cam constantly falling off your windshield like me, then you’re probably wondering what you can do. The answer is to apply an adhesive– the best way to do it is to use VHB tape. VHB (a.k.a. Very High Bond) tape is a very strong double-sided tape, that will help keep your suction cup stuck to your windshield while holding up the weight of the dash cam. You’ll typically find 3M VHB Tape since the VHB tape is proprietary to 3M.
Materials Used For This Project
3M VHB Tape comes in a variety of shapes and sizes, but the one you want is the circular one (or rectangular if your dash cam requires it) that fit your suction cup size. You will also need isopropyl alcohol to clean the surface that you’ll be applying the tape to, as well as to the suction cup itself. It doesn’t matter what percentage rubbing alcohol you use, any type will adequately clean the surface.
A microfiber towel will also be useful for cleaning while leaving minimal lint behind. Finally, if you are not able to install this tape outdoors in the hot sun, you will need a heat gun for proper application of the VHB tape. You might read come across some “bad” reviews on VHB tape if you’ve looked on Amazon, but I believe that most of these are due to improper installation. If there is not enough heat to slightly melt the adhesive on the tape during the installation, the suction cup won’t adequately stick to the glass, leading to the dash cam inevitably falling off your windshield.
Isopropyl Alcohol: Amazon Basics 99% Isopropyl Alcohol (16oz)
Microfiber Towel: HOMEXCEL Microfiber Cleaning Cloth (12-pk)
3M VHB Dash Cam Circular Tape: 2.2″ / 2.76″ / 3.15″ / 3.54″ / 3.74″
Heat Gun: Wagner Spraytech HT1000 Heat Gun Kit
How to Apply 3M VHB Tape to the Suction Cup and Dash Cam Mount
Prepping the surface is very important; use isopropyl alcohol and wipe down the area with a microfiber towel where you plan to apply the suction cup to. Also clean the suction cup itself.
This is the 3M VHB tape I got, which measures 2.2″ in diameter. You should measure your specific dash cam’s suction cup to determine what size VHB tape you should get.
After wiping down your application surface and suction cup and allowing it to fully dry, remove the backing off one side of the VHB tape and carefully apply it centered on the suction cup. Press down on it to allow it to adhere as much as it can to the suction cup.
Remember that you need to do this on a very hot day (I’d say at least 80 degrees Fahrenheit). Ensure that the windshield is in the direct sunlight and is almost hot to the touch. If it’s not hot enough, use a heat gun to heat up the windshield area so that it is hot prior to applying the suction cup.
Peel the backing off of the other side of the VHB tape and carefully apply the suction cup with VHB tape to the final location on the windshield. Apply heavy pressure on the suction cup (and adhesive) to the windshield. What you want is for the heat on the windshield to slightly melt the adhesive of the VHB tape so that it melds to the glass. Trust me, if you do not apply this on a hot windshield, the VHB tape will won’t adequately meld to the glass and it will later fall off again while you’re driving.
If you’ve applied the suction cup with the VHB tape properly with lots of heat, the suction cup and adhesive will form a very strong bond that will keep your dash cam up on the windshield without ever falling off.
I initially installed my dash cam with just the suction cup alone and it would barely hold up for more than a few seconds. I then applied the VHB tape in the evening and although it stuck, the VHB tape didn’t meld to the glass causing the dash cam to fall off every few days or so. Finally, I applied it again on a hot day while applying a lot of pressure. I then let it bake in the sun for the rest of the day. It’s been months now and it has yet to fall off the windshield again.
