1. Thread paste or pipe dope – thread paste is probably the most used product on a plumber’s truck. This thread helps form a seal on threaded connections by filling in the tiny voids. Applying the paste will also act as a lubricant and help to tighten the connection snugly. Always check to make sure the one you picked up is the correct type for the plumbing you have. Some pastes should not be used on plastic threads. There are a few other situations that plumbers like to apply the paste, such as on the mating surfaces of certain kinds of unions, inside compression fittings, inside flared connections, or on the bottom of certain types of gaskets.
2. PTFE Tape. PTFE (polytetraflouroethylene) tape, or thread tape, is commonly (and mistakenly) called Teflon tape. On threaded connections, PTFE tape can be used in place of, or along with pipe dope. It is important to not “overwrap” the threads with the tape, as this could possibly result in putting too much stress on the fitting and crack it – causing more leaks.
4. Caulk. Latex and silicones caulk should never be used to seal any piping. They should only be used to seal fixtures, or seal around areas that should not allow water in. Examples includes, caulking down sinks, tub spouts, outside penetrations, maybe even faucets. I never recommend using silicone on the underside of sink, shower and bathtub drains in lieu of plumber’s putty. I could be a permanent fixture if you ever need to go back in and do another repair.
3. Plumber’s putty. Putty should only be used on the underside of something that will be tightened or compressed down, such as the underside of sink drains, shower drains, and bathtub drains. Some plumbers will use it underneath stainless steel sinks to seal them to the countertop as well.
7. Wax Ring – this is the ring your toilet sits on. It is gently compressed when you have a new installation or a repair. This is a 2 dollar ring and once it is compressed – it never really is the same. If you have to remove your toilet for a repair or a new installation, go ahead and spend the extra 2 bucks and get a new ring – it will save you in the long run!