Step 5 · Clean and Prepare the Cast Iron Pipe

This is the step people usually slow down on. Go finger-tight first, then a quarter turn. No rush — replay the clip whenever it helps.

Once all the lead and oakum are removed, the inside surface of the cast iron pipe hub must be thoroughly cleaned. Use a wire brush—either a handheld version or a drill attachment—to scrub the inside of the hub. The goal is to remove any remaining residue, corrosion, or debris to create a smooth, clean surface for the new flange's rubber gasket to seal against. Use the shop vac to remove all the dust and particles created by the brushing.