Prepare Wall Drain Opening

What happens here

After removing the old plumbing, clean the inside of the wall drain pipe thoroughly with a paper towel to remove any debris or old sealant. Use a utility knife or reaming tool to deburr and smooth the cut edges of the pipe, both inside and out. This step is crucial for achieving a tight, leak-free seal with the new fitting.

Goal: Clean and deburr the inside of the exposed drain pipe coming from the wall to ensure a smooth, secure connection for the new fitting.