How To Seal a Sliding Glass Door with Flex Shot

“How To Seal a Sliding Glass Door with Flex Shot” was written by a member of the Flex Seal Editorial Team. 

Sliding glass doors are your gateway to the great outdoors, but leaks that let the outdoors in? Not so great. Thankfully, Flex Shot can help you seal and protect your sliding doors in no time. Keep reading to learn how to seal a sliding glass door fast with Flex Shot.

Materials Needed 

Flex Shot Clear

● Box cutter or knife

Paper towels

Note: Before using Flex Seal products, read all directions carefully and take proper safety precautions, such as being in a well-ventilated area and wearing protective gear while applying. 


1. Preparing to Use Flex Shot

The first step is to prep! Make sure the area you’ll be applying Flex Shot to is clean, dry, and free from grease, oil, or dirt. Next, grab your can of Flex Shot and a box cutter or knife. Cut the tip of the extension tube at a 45-degree angle so that it’s large enough to achieve the desired bead size. Please use caution when doing so. 

Flexpert Tip: The farther down you cut on the extension tube, the larger the bead size. 

2. How To Seal a Sliding Glass Door With Flex Shot

Flex Shot’s easy-to-use nozzle makes application a breeze. First, you’ll want to seal along the border of the door where the glass meets the frame. We recommend using Flex Shot Clear for this application for a more seamless look. If you’d prefer a bit of colour, Flex Shot is also available in white, black, or almond. Hold the can at a 45-degree angle, push on the nozzle, and apply directly to the desired area in a smooth, controlled motion.   

Flexpert Tip: You can control the size of the bead by adjusting your speed.  

Flex Shot can be tooled within 20 minutes of application. Use your finger or a caulking spatula to fill the desired space and smooth out the product. Use a paper towel to remove any excess Flex Shot. 

Next, use the same techniques to apply Flex Shot along the outside of the sliding glass door frame, avoiding where the door meets the track. You can stick with Flex Seal clear or use white, black or almond to match your door frame. After application, allow 24-48 hours for the product to fully cure.

Flexpert Tip: Dry time will depend on bead thickness, ambient temperature, and humidity. 

Flex Shot can be applied in temperatures ranging from -17.7°C to 65.5.°C, and once cured, it can withstand extreme temperatures, ranging from -60°C to 176.6°C. Our super thick waterproof sealant will remain flexible and will not fade, dry, shrink, crack, yellow, or deteriorate, making it perfect for indoor and outdoor projects.

3. Finishing Up and Storing Flex Shot

Now that your sliding glass door is protected with the sealing power of Flex Shot, it’s time to store the product properly. Remove the extension tube and clean it with a dry paper towel. Next, extend a small bead past the applicator tip to form a plug. This plug will cure and help the remaining product stay fresh. Simply pull or cut off this plug when ready to reuse.

Now you know how to seal a sliding glass door. Leaks can put a damper on any mood, but the power of Flex Shot can help keep your sliding glass door waterproof and worry-free.

By Amanda Tacconi

Amanda Tacconi is an Editor at The Flex Seal Family of Products, where she focuses on writing and editing articles for the company’s blog.

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