Sealant is a type of mechanical seal that is widely used in domestic and industrial applications in order to fill up unwanted gaps and openings that may cause the seepage of water, gases or any particulate matter. Mating of two or more parts together results in gaps, which adversely affect the integrity and the performance of the object.

Sealants are effectively used to fill up gaps between the surfaces and close off any spaces that may occur. However, sealants are not an alternative to adhesives while some sealants do have adhesive properties. Curing is a process under which the applied sealant is toughed or allowed to settle down effectively. The curing process and duration is solely based on which sealant is being applied to the joints.

Curing process for some sealants may take few hours whereas for some it may take up to weeks. The methods that are used to cure different types of sealants are as follows; What is curing? Under this curing procedure, the sealant is applied at the joint and left untouched at room temperature. The moisture in the air cures the sealant. Ambient temperature sealant usually have a curing time from thirty minutes to four hours.

The thickness layer of the sealant as well as the ambient humidity directly affects curing time. Silicone and epoxy sealants are usually cured using this method. Thermal curing. Currently, there are more than forty types of sealants available in the market, out of which the most commonly industrially used sealants are as follows:. To decide which sealant to use of all the available sealants, it must be made sure before application that whether the joining material is compatible or not.

Having a sealant being applied on an incompatible material may result in the degradation of the material and failure to seal off the joint. Step one — Clean up the surface: Clean the surface with a cloth and make sure that the joints are dry and grease and dirt free.

Step two — Prepare the joints: Prepare the joints by aligning them in the way you want them to be sealed. Put masking tape around the edges in order to avoid any mess. Step three — Apply masking tape: Insert backing material between the joints.

Addition of a backing material avoids the seepage of sealant deep into the joint during curing process. Step four — Application of sealant: The sealant is applied manually or using a sealant applying machine. Handguns are the most common type of sealant applicators. Step five — Joint smoothing: The joint is smoothed out using a plastic card. This allows for a better sealant contact with the joint. Individuals who are working with objects that get extremely hot should consider purchasing a high temperature silicone sealant.

It is also resistant to aging, vibration, and shock. Therefore, this type of sealant is perfect for binding objects, such as valve covers, thermostat housings, and fuel pumps in automobiles. It can also be used for some industrial purposes, such as sealing various gaskets, cable insulation, and ductwork. Electrical Grade Self-Leveling silicone is another great silicone sealant. It does not contain acetic acid or any other corrosive chemicals.

Furthermore, it is highly resistant to weathering, moisture, the sun, and extreme temperatures. Therefore, it is an excellent adhesive to use on materials that are constantly exposed to the elements. For example, this sealant can be used to bind metal, glass, wood, ceramic, or plastic together. A multi-purpose sealant should still be resistant to weathering, extreme temperatures, moisture, and vibrations. Furthermore, it can be used on several surfaces, including aluminum, ceramic, glass, metal, wood, plastic, granite, and more.

Multi-purpose sealants are also good to have around when home repairs are needed. Silicone sealants are strong and have many purposes. Silicone caulk is far superior to polyurethane for certain applications. It adheres very well to almost any material but it does not adhere well to wood surfaces. Also, silicone caulk is not paintable, so be careful about where you use it.

The silicone in the caulk prevents the paint from bonding with the caulk. On the other hand, it is ideal for wet or exterior surfaces because it holds up well in sunlight and extreme temperatures.

Most manufacturer warranties are twenty years. It costs about twice as much as polyurethane caulk but it will last twice as long. One of the best uses of silicone caulk is for sealing around plumbing fixtures such as bathtubs, showers, toilets, and sinks. It is also excellent for weatherproofing your house. Use it to seal around doors, windows, and utility cables coming in from outside, and you will be going a long way to minimizing drafts.

Sealing those openings can also help keep out rodents and vermin. Silicone is the best sealant to use in colder temperatures. Unlike polyurethane caulk, the cold temperature does not affect application. Oxime or neutral silicones do not have this smell. In general, oxime silicones are better in almost every aspect, including adhesive strength, suitability on different materials, and resistance. They are also more expensive. Silicone sealants can be diluted to make it cheaper.

The quality of a silicone sealant is largely dictated by how pure it is. However, be careful of sealants that are very diluted. Generally, highly filled silicone sealants are prone to cracking and turning brittle, and their adhesive strength is also not as good.

They also tend to discolour. When used on slightly porous materials such as natural stone, marble, or granite such as on counters , the plasticizers and other diluents in a diluted silicone sealant can migrate out of the sealant body and into the stone, discoloring it.

This is called leaching, and it is a common problem for cheaper silicone sealants. As silicone sealants are generally one of the better choices for use in bathrooms and kitchens, many sealants require anti-fungal and anti-mould properties.

This can be achieved by the addition of chemicals to prevent mould growth, and are typically called sanitary sealants. We have heard people in the industry say that the acid in acetoxy silicones will kill fungal spores. This is NOT true. Silicone sealants do not have any natural resistance to fungal growth. Do not use a normal silicone sealant in your bathroom and kitchen — you could be looking at mould in as quickly as two weeks.

Always ask for a sanitary grade, anti-fungal silicone such as our Pereseal AF Bathroom and Kitchen silicone. The quality and efficacy of the anti-fungal properties depend on formulations and the concentration of anti-fungal chemicals in the sealant.

Not all anti-fungal sealants are the same. For example, our Pereseal AF is specifically formulated for use in hot and humid environments, and is used by many 5-star hotels in Singapore for its superior properties such as The Regent and Four Seasons Hotel.

However, these anti-mould properties are not a substitute for regular cleaning of your bathrooms and joints. There is a lifespan to the sanitary properties. Generally, the dirtier a bathroom is, the shorter the lifespan will be.

What homeowners should know is that the better a sanitary sealant, the longer it is before your sealant grows mould. The length of time can be as long as 20 years with a good anti-fungal sealant, in well-cleaned conditions. HDB has a list of approved construction materials. This list of materials is for the larger contractors building the whole blocks; not so much for the general contractor doing renovation works. Common applications : Around walls, between walls and skirting, door frames, air-conditioner ducts and pipes especially in wall penetrations.

In fact, acrylic sealants were first sold in putty cans. It does not have the flexibility and appearance of a rubber like silicones; instead, acrylics look more like your wall, down to its matte appearance. Is it also paintable. For that reason, it is usually found on joints near the wall, such as on the floor skirting, door frames, and wall penetrations.