"Willow" wrote in message
...
Hi

What's the best way to clean rust & hard water grime off a pipe thread in
the shower? I need to replace the shower head, but the replacement bits
won't fit, despite the thread being the same size.

Any ideas? I'm onto my second application of CLR, don't know what to try
after that.

SNIP

It definitely is a buildup causing the trouble? Usually as the thread would
be covered by the old bits it would protect it, and taking off the old bits
would at the same time remove any buildup. Can you see the buildup? Even try
putting the old bits back on if you have them, only lightly by hand to test
it. While the thread may be the same size, the thread may not be the same
type. Sometimes they have coarse or fine thread, meaning the gaps in the
thread are further apart or closer together.
If all is good, and it is the buildup, you could try vinegar. I have heard
that can help. Even with the CLR, hook up something so it is sitting in the
CLR for a while.
All the best with it.