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Flex Seal Products 4 in. x 5 ft. Black Waterproof Flex Tape

Flex Seal Products

SKU: 156375

  • 4" x 5'
  • Super strong adhesive
  • Bonds together almost any objects
  • Conforms to any shape or object
  • Seal out water, air and moisture
  • Apply in hot or cold, wet or dry and even underwater
  • Bond will increase with time & pressure
  • Extra wide to quickly cover large cracks, gaps and holes
  • VOC-free
  • Environmentally friendly
  • UV resistant


FLEX TAPE® is a super strong waterproof tape that can instantly patch, bond, seal virtually anything. It can be applied on dry or wet surfaces and it even works underwater! Flex Tape’s powerful adhesive bonds instantly to almost any surface and actually gets stronger with time and pressure. Has a thick, flexible rubberized backing that conforms to any shape and object. UV resistant, VOC- free, and withstands extreme temperature and weather conditions.

Common Flex Tape Applications:

  • Leaky roofs and ceilings
  • Damaged gutters and down spouts
  • Boats, kayaks, personal watercrafts, canoes, and other outdoor equipment repairs
  • Repairs for mobile homes, RVs and campers
  • Leaky PVC and plumbing pipes
  • Sprinkler system, pool, and spa leaks and repairs
  • Patch and seal windows, doors, walls, seams, and vents
  • Repair air ducts and HVAC systems
  • DIY projects
  • And much more.

Flex Tape will work on:

PVC, acrylic, metal, steel, copper, aluminum, wood, ceramic, porcelain, tile, glass, rubber, fiberglass, stucco, plaster, stone, cement, concrete, dry wall, EPDM roofs, some plastics, fabrics, vinyl and so much more.


  1. CUT. Leave backing on tape and cut to desired dimension. Make sure to use a high quality utility knife with disposable blades or a razor blade when cutting.
  2. PEEL. Remove the backing from the tape.
  3. STICK. Apply tape to a clean surface and press down firmly.
  4. SEAL. Using your fingers, plastic squeegee or roller, press down firmly and remove any air pockets.

*Flex Tape is a temporary, emergency repair and is not meant to be a permanent fix.

**Flex Tape may not bond to all hoses.


  • For maximum adhesion on porous surfaces, using a standard blow dryer will help the adhesives bond with the surface.
  • Flex Tape’s bond will increase with time and pressure. Continued firm pressure will help increase adhesion.
  • Once fully bonded, Flex Tape cannot be repositioned.
  • Flex Tape adhesives may resist bonding to some plasticized or waterproof materials, siliconized, greasy, oily, dirty, or porous surfaces.
  • Certain fabrics such as canvas, nylon, polyester, synthetics, cotton and some other materials may need up to 24 hours to reach maximum hold.
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Q: What temperature should I apply it?

A: Flex Tape can be applied in a wide range of temperatures, from 20° F to 120° F.

Q: Can I paint over it?

A: Most paints will not adhere to Flex Tape. However, Flex Seal aerosol may be used as a primer to transform the appearance of surfaces where Flex Tape has been applied.

Q: I’m trying to adhere it to fabric, but it’s not sticking. Is there anything I can do to prep the surface?

A: Flex Tape can be heated with a standard hair dryer to help the adhesive bond with the fabric. Also, continued firm pressure and time will help increase adhesion. Some customers have found it helpful to first prep a fabric surface with Flex Seal aerosol, let it dry, and then apply Flex Tape.

Q: Can I use it on my radiator hose?

A: No. We do not recommend using Flex Tape on radiator hoses.

Q: Can I use it on a tank used to hold gas or oil?

A: No. We do not recommend using Flex Tape on a gas or oil tank.

Q: Can I use it to repair a car or bicycle tire?

A: No. We do not recommend using Flex Tape to repair tires due to the extreme pressure.

Q: Can I use it on a container that holds water for drinking?

A: It has not been tested on potable drinking water.

Q: What is the maximum pressure it can withstand?

A: The maximum pressure Flex Tape can withstand will vary based on the substrate and the conditions under which it is applied. It’s always best to test a small area first.

Q: If I’m using it to patch an above ground pool, is it best to apply it to the inside or the outside of the pool?

A: Both! Flex Tape forms a super strong bond with itself, so if you’re patching a pool it’s best to first apply Flex Tape to the interior side of the pool wall and then place a second piece of Flex Tape to the exterior. Remember to cut your Flex Tape larger than the area of the leak. You do not need to drain the pool prior to applying it. Flex Tape is a temporary, emergency repair and is not meant to be a permanent fix.

Q: Can I use it to repair an air mattress or inflatable?

A: Flex Tape can be used as a temporary, emergency repair to an air mattress or inflatable. However, it may not bond with all materials. Always test before use.