Home PVC plumbing pipes are designed to prevent leaking, but an air or water-tight seal is not usually achievable. To make the joints air and water-tight, you need to use adhesives and sealants. A wide variety of sealants and adhesives are available in the market, designed for use for different surfaces, temperatures, and humidity. In addition, your choice of a suitable adhesive or sealant should be influenced by the strength and tack as it defines the ability to create a strong and permanent bond with the PVC pipes.
Understanding the different types of adhesives and sealants and specific uses will help you achieve water-tight seals when dealing with different types of home plumbing pipes.
How to Decide On the Right Adhesive or Sealant for Your Plumbing Needs
Adhesives and sealants are available in different forms with unique features suitable for different plumbing needs, surfaces, and materials. The specificity of plumbing needs has resulted in the manufacture of specific adhesives, such as solvent or acrylic, clear or pigmented, and removable or permanent. However, your decision regarding a suitable adhesive or sealant should be influenced by the fitting material or pipe (PVC, CTS, and CPVC), the nature of the connection (slip or threaded), and code requirements.
Types of Adhesives and Sealants
PVC Primer and Cement
PVC primer is recommended for sealing plumbing joints as it guarantees water-tight connections, especially for slip connections. It is considered one of the most effective plumbing adhesives and sealants because it softens the PVC pipes through a chemical reaction. The chemical components responsible for the reaction include acetone, cyclohexanone, tetrahydrofuran, and methyl ethyl ketone. Because of the chemical reaction, the PVC pipes will be bonded together because of a chemical reaction and not glued like in the case of other adhesives.
In addition, PVC plumbing is ideal for home plumbing since it can act as a cleaner to remove grease, oil, and other dirty substances from the surface of the PVC pipes. However, achieving the best connection when using PVC primer requires PVC cement which helps in making the pipes inseparable and water-tight. Also, you should note that PVC primer is only effective when wet; hence, you should be ready to apply the cement just after applying the primer.
Joint Compound
When joining threaded pipes during plumbing, you should consider the ability to unscrew and re-screw. Commonly, plumbers use thread tapes, usually made from Teflon, to seal the joints because of the ease of removal. However, a suitable adhesive to use for threaded connections is the joint compound (pipe dope), which is made from kaolin clay, vegetable oil, rosin, and ethanol.
The joint compound works by filling the gaps that might be present between the threads to prevent leakages. Joint connections allow unscrewing or re-screwing of threaded joints as it never fully dries; hence, serving the purpose of a lubricant. You should use joint compound together with thread tape to achieve the best results, but not for PVC pipes. However, when buying joint compounds for your plumbing needs, you should consider the technical specifications, particularly regarding the type of pipe.
Plumbing Silicone Sealants
Silicone sealants are liquid adhesives mainly used for repairing materials, such as fishing joints and fillings seams. Nonetheless, silicone sealants are suitable for home plumbing purposes because of their durable elasticity and stability in low and high temperatures. To achieve a waterproof seal, you need to apply silicone sealant properly. Before you apply the sealant, you need to clean the surface to get rid of dust or dirt that can compromise the strength of the seal. Once you apply the sealant, you need to allow it to cure for at least 24 hours.
Pipe Thread Sealant
Pipe thread sealant is an anaerobic resin compound containing PTFE compounds, contributing to its functionality and durability. Anaerobic resin compounds are considered ideal for sealing pipes because they do not shrink up like joint compounds. Like other liquid sealants, you need to spread the pipe thread sealant on the surface before joining the pipes.
Sealants and adhesives during plumbing are encouraged to prevent leaking or sipping. However, the decision regarding a suitable sealant or adhesive should be influenced by the type of pipe, technical specifications, nature of the surface, and ability to create a strong seal. In addition, you need to use the right type of sealant and adhesive to get a water-tight seal.
