Sealants Buyer Guide

Sealants buyer guide

Whether you work in an industrial setting or you’re simply an avid DIYer, you’ve probably come across sealants on numerous occasions. But what you may not be familiar with are the specific applications, properties and limitations of the various types of sealant.

What is a sealant?

The term ‘sealant’ refers to an extensive range of products that fall within the category of adhesives. Typically, sealants have an appearance and texture similar to that of a gel, which on inspection may seem identical to various polymer-based adhesives. But the difference between a typical adhesive is the way in which a sealant will maintain its stability and elasticity at both low and high temperatures.

In addition, a sealant is usually more resistant to moisture, chemicals and weathering, making it more robust and reliable when performing repairs.

In order for a sealant to provide its adhesives and protective properties, it needs to cure (or dry) in place for a specific period of time. Curing requirements vary from one product to the next. However sealants generally cure when humidity is between 5% and 95% and the ambient temperature is between 40° F and 100° F.

Depending on the type of sealant, it can take anything from 24 hours to several days for it to fully cure.

What are silicone sealants?

Silicone sealant is the most widely used type of sealant by a significant margin. Robust, water resistant and exceptionally versatile, silicone is inexpensive and easy to use.

Silicone is routinely used in kitchens and bathrooms to create waterproof seals around sinks, or anywhere moisture levels are high around the home. Capable of creating an exceptionally strong and long lasting bond, silicone sealant can be used to bind various materials including glass, metal and plastic.

Silicone is also used to seal windows into their frames, or in the manufacture of aquariums. With its capacity to withstand high temperatures, silicone is also an important component in the manufacture of household appliances, electronic devices and even motor vehicles.

Other types of sealants

Depending on the nature and requirements of your project, silicone may not be suitable. In which case, you’ll have the option of a wide variety of specialist sealants to choose from, including:

High temperature

High-temperature sealant is designed specifically for applications in areas with exceptional temperatures. Properties vary from one product to the next, though some heavy-duty high-temperature sealants can cope with temperatures of up to 600° F.

High-temperature sealants are routinely used in the repair and maintenance of ductwork and for sealing gaskets in industrial environments.

Electric grade self-levelling

This is a type of silicone that is routinely used in the manufacture and maintenance of electronic products and components. It is also exceptionally durable and completely weather resistant, making it ideal for use on materials that are exposed to the elements outdoors.

Multi-purpose

There’s an extensive range of multi-purpose sealants to choose from, which are useful for a wide variety of everyday applications. Multipurpose sealants are usually compatible with various materials, which include aluminium, ceramic, glass, metal, wood, plastic, granite and more. However, they are not typically the strongest or most durable of sealants available.

Caulk

An alternative to conventional sealant is caulk, which differs from the conventional by way of elasticity. While caulk is made from a flexible material and does allow for a certain amount of expansion or contraction, caulk is comparatively rigid when dry and not nearly as elastic as silicone sealant.

How to use sealants

You’ll find detailed instructions on how to use any given sealant in the manufacturer’s guidelines supplied with the product. However, the application of most sealants typically follows these basic steps:

  1. Before getting started, ensure that you have chosen an appropriate sealant for the job. Never attempt to use a sealant for a purpose it was not designed for.
  2. Always make sure that the surfaces you are working with are clean, dry and free of dust and debris, which may otherwise compromise the performance of the application.
  3. If there is any residual sealant on the surface from a previous application, ensure it is removed completely using a specialist tool or a sharp knife.
  4. Use masking tape to protect the surrounding surfaces and create the cleanest possible line, which you will subsequently remove before the application dries.
  5. Hold the gun or applicator at an angle of 45° and gently but confidently push towards yourself as you apply the sealant.
  6. With the line created, wet your finger with some soapy water and smooth out the seam with a gentle ‘scrape’ along the surface.
  7. Tend to the finer details around the project area after the application has dried, using a special spatula or a knife to remove unwanted sealant from the surrounding surface.

The sealant manufacturer will specify what kind of care and maintenance is required, which in most instances involves regular cleaning and occasional touch-ups where splits or cracks occur.