Galvanized water pipe

View inspection footage about galvanized water lines and what you should know at

https://youtu.be/ZYKU7ctuzcA

Galvanized water pipe is common in homes built in the early 1960's or earlier. Galvanized water supply however corrodes from the inside out. Since the threaded ends  are the thinnest part of the pipe, they are often the first section to leak. Very often, there is a buildup of scale or rust at the end of the pipe. Occasionally, there will be what looks like a blister or scab in the pipe, though it is not near a thread. You may be tempted to scrape or poke this corrosion or scab, but do not as it is a leak waiting to happen.

The only way to fix this type of plumbing problem is replacement. With modern use of PEX supply lines, this makes replacing accessible supply lines fairly easy.

"scab"
leakage at threads
More corrosion/leakage