How Do You Seal a Truck Bed Cap?

Truck bed caps are a great way to protect the contents of your truck bed from weather, theft and debris. They also add a sleek, streamlined look to your vehicle.

But if you want to get the most out of your truck bed cap, you need to make sure that it is properly sealed. Sealing a truck bed cap is relatively simple and can be done in three steps.

Step One: Clean and Prepare
The first thing you need to do is give the area around the edges of the truck bed cap a thorough cleaning. Use soap and water to remove any dirt, oil or other residue that could prevent the sealant from sticking properly. Once it’s clean, let it dry completely before moving on to step two.

Step Two: Apply Caulk
Once the area is dry, use an all-purpose caulk around the edges of the truck bed cap. Make sure that you apply enough caulk so that there’s a tight seal between the cap and the truck bed. You can use a caulk gun for this step if you don’t want to use your fingers.

Step Three: Smooth Out
After applying the caulk, use a wet finger or a rubber spatula to smooth out any uneven edges or lumps in the sealant. This will ensure that you get a smooth finish and help prevent any air leaks or water damage. Allow it to dry completely before putting anything in your truck bed.


Sealing a truck bed cap is an important part of keeping your vehicle looking great and protecting its contents from weather and theft. By following these three steps—cleaning, applying caulk, and smoothing out—you can ensure that your truck bed cap is properly sealed for maximum protection.

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Karen Watkins