CLR dissolves calcium deposits not corrosion. WD-40 displaces water and is useless for what you need.

If the nozzle screwed on the hose easily and you didn't cross thread it try this... get a can of PB Blaster (pretty common) or Kroil (less common) and repeatedly apply over a couple days.

There are pliers designed to grip curved surfaces that will help you and you can wrap the nozzle and hose with a thin leather strip to minimize damage.

Thank you justalurker. I can't tell whether it's cross-threaded, hopefully not. If it is, is there any hope?

In the meantime, Lowes has PB Blaster, so I'm going to give that a try.

Walmart also has PB Blaster

If it's cross-threaded disassembly will require deft force and the right tools to not make it worse.

Pooched outside (male) threads can be dressed with patience and the correct files. Repairing Inside (female) threads is more problematic, but that would be the nozzle and much less of a loss.

It might be easier and cheaper to just cut a few inches off the hose and install a new male end 2-4 minutes and about $2-$4.

Just throwing out another possible fix rather than throwing away the hose.

Since we haven't identified the hose "cutting a few inches off the hose" might lead the OP to "throwing away the hose".

Hard to see beyond the keyboard, and I don't assume, so I always favor the least destructive approach first. Butchering the hose would be a last resort for me.

Ok, update, and thanks to all for the advice. I called my plumber, hoping they might just stop by and take care of it for me as a courtesy (but no). He said to get a pair of channel locks since it was probably a cross-threading issue. $3.87 each and voila, solved. Best eight bucks I ever spent.

Now after two weeks of no rain, we'll probably get deluged. You know how these things go!

But I'm pleased. The yard was seeded a week ago and I had to water since Mother Nature is not cooperating with me! :)

The right tool for the job will usually get it done.

This post was edited by justalurker on Thu, Oct 9, 14 at 23:12

This is what I do and it works on properly threaded but corroded couplings, despite any nay sayers. First heat it up a little...no need for torches if you live in a hot sunny clime & its summer, a blazing summer sun will heat the metal up plenty. Just get it hot enough that it is painful to the touch but not necessarily blistering heat. Then liberally apply WD40. Try to get the lubricant INTO the threads, wiggle the nozzle as much as you can, spray, wiggle, spray, wiggle, etc. Let it sit in the sun for a couple of hours. Get a hammer and holding the HOSE near the nozzle, with the threads on the downward, gravity side, start tapping all around the nozzle's connection, tap harder all around, keep it up for a minute or two. Don't hit it hard enough to do any damage but don't be a lightweight about it either. Now try to unscrew it...hopefully you see a little wiggle room now. Spray some more WD40 into the threads...wiggle wiggle wiggle....hammer hammer hammer. Now unscrew the damn thing. Told you it worked. No need to damage a perfectly good hose...especially the good ones...clean the screw thread and grease them well before putting a nozzle or anything else back on...a wire bristled brush would be useful if you see corrosion on the threads.