How to Tighten Galvanized Pipe

Turn off the main water valve.

Fit your wrench onto the lock nut that secures the fitting to the loose pipe. Turn the wrench counterclockwise to loosen. Apply a few drops of penetrating lubricant if the fitting is very snug.

Remove the pipe from the fitting and wipe away the excess lubricant with a rag.

Pour vinegar onto a metal-bristled scrub brush and clean away any corrosion on the pipe and fitting threads if necessary. Wipe the threads clean when finished.

Squeeze a fair amount of anaerobic sealant onto the threads and rub it in so that they are completely covered. This type of sealant keeps out air and water and prevents further corrosion. It also creates a tight bond between the pipe and fitting threads. Wear gloves for this step.

Thread the fitting back onto the pipe and replace the lock nut. Secure the lock nut as tightly as possible with your pipe wrench.

Allow the sealant to set and cure for an hour before turning your main water valve back on.