Evidently, it’s impossible to make a spring both good and noncorrosive:
I found a suitable (i.e., good, but rust-prone) spring in the Big Box o’ Medium Springs:
Unlike the repair for that sprayer, this spring turned out to be long enough to work perfectly. I have no idea how long I can keep this up, but … at least I’m now keeping pace with the failures.
The Smell of Molten Projects in the Morning 
Comments
4 responses to “Repairing Yet Another Garden Sprayer”
Seems like 6Al4V ought to work just fine.
And hey, turns out you can buy it on Amazon!
Missed my chance: “Currently unavailable. We don’t know when or if this item will be back in stock.”
I’ll put it on my Santa wish-list… [grin]
How about a plastic spring?
for example, http://www.advanexusa.com/plastic_springs.html
This scares me right off: “E-mail for the latest catalogue and prices!”
My rule of thumb is that if I must ask for their prices, I can’t afford them… but if I were making a bazillion sprinkler heads, a non-corroding spring would be a nice selling point!