How to Loosen a Rusted Sink Drain Pipe

Sink drains usually consist of three pipes, starting with a straight pipe running directly under the sink. This pipe attaches to a curved pipe, called a P-trap, which connects on its opposite end to another straight pipe that runs into the wall, joining the home's plumbing system. The drain pipes connect together with large nuts. When the drain pipes are made of metal, they will rust over time and are difficult to take apart.

Things You'll Need

• 2 slip-joint pliers
• Penetrating catalyst
• Hacksaw

Instructions

1. Remove items from under the sink so that you have access to the drain pipes. It is much easier to work under the sink without anything in the way.

2. Spray the rusted pipes at the joints with a penetrating catalyst. Use the straw applicator on the nozzle to get the catalyst into the area between the nut and the end of the pipes as close as possible. Soak the connections with the catalyst and let it set for 20 minutes.

3. Hold the pipe below the nut with a pair of slip-joint pliers and grasp the nut with another pair of slip-joint pliers and turn it counterclockwise. If the nut will not move, spray it again with the penetrating catalyst and keep trying to work it loose.

4. Cut the pipe off at the nut with a hacksaw if it will not come apart with the penetrating catalyst. It is always best to unscrew the drain pipes, but sometimes the only option is to cut it off with a hacksaw.