Skip to Content
5 min reading time
Plastic fantastic!

Plastic sealant:
A sealant for the modern world

When it comes to selecting the best plastic sealant for the job, there’s a lot of choice out there. UniBond has you covered.

Plastic sealants: Why you need them

When we think of sealant, we usually think of it as being used to seal around ceramic showers, sinks and bathtubs, or wooden window frames, door frames and skirting boards. But increasingly, more and more elements and items in our homes are made of durable plastics like polycarbonate and uPVC. And because accidents still happen and gaps still need filling with this modern material, a sealant that is compatible with plastics (uPVC) is a great item to have in your toolbox. 

There are several types of sealant that work effectively with plastics (uPVC). Modified or hybrid polymer sealants make an excellent waterproof sealant for plastic (uPVC), as they can be applied in wet conditions, offer great adhesion to non-porous surfaces without needing a primer, are generally paintable and have elasticity, strength and shock-resistance.

Silicone sealant for plastic (uPVC) can be an option, as well. It is also waterproof and highly resistant to weather, including extreme hot and cold temperatures, making it ideal for outdoor as well as indoor applications. Silicone sealant offers excellent flexibility and elasticity, giving it long-lasting shock-resistance, too.

The best polymer sealant for plastic (uPVC)

UniBond Seal & Bond is a fantastic sealant for plastic (uPVC). It utilises Henkel’s patented Flextec technology, to create flexible polymer chains which resist shocks and extreme temperatures. UniBond Seal & Bond also offers excellent properties and can be applied to damp and wet surfaces.  

The best silicone sealant for plastic (uPVC)

UniBond Window & Door Frame creates a durable and flexible perimeter seal for multiple materials – including uPVC and polycarbonate plastics as well as wood and metal – making it suitable for most exterior window and door frames. As well as providing strong and flexible sealing, this silcone adhesive for plastic (uPVC) is waterproof, enabling it to repel harsh weather conditions and protect any home from the elements.

Plastic sealant: How to use it

  1. Clean. Ensure all surfaces are free of old sealant and clean and dry, in order to achieve the best possible seal. Remove old sealant, then use a cloth moistened with white spirit to remove any remaining dirt and accumulated grease. Allow to dry.
  2. Prepare. Cut the tip off the cartridge and the sealant nozzle at a 45-degree angle to create an aperture that matches the width of the joint you are sealing. It’s best to cut too small first – if it’s not big enough, you can make the aperture larger (but not vice versa). Insert the cartridge into a sealant gun.
  3. Seal. Place the tip of the dispenser nozzle at one end of the joint you are sealing and gently but firmly squeeze the sealant gun’s trigger. Move along the joint steadily to create a smooth, continuous bead of sealant. 
  4. Finish. When complete, use UniBond’s Sealant Smoother Tool to tool and smooth the sealant bead into the joint and achieve an optimal finish. Leave to dry as per the product’s instructions.


If you need to remove old sealant, you can use UniBond 2in1 Sealant Remover and Smoother Tool to break it down and make it easy to remove. To complete the job without damaging any of the materials around the joint you are sealing, use UniBond Silicone Sealant Remover.

Share this project

You may also be interested in