Kitchen Sink Strainer Nut Falling Off

GearHd6

I'm currently going on my fourth kitchen sink strainer. What happens is over time (maybe a year?) the nut on the underside that holds the strainer tight against the sink will just all of a sudden fall off. It doesn't crack or break, just slips off the strainer threads. When I go to install it again the nut just slips right on, like it's now to big for the strainer. What is going on here? Is this a reaction between the white metal nut and the steel strainer? What is a GOOD quality replacement strainer? Thanks for any help!

Thurman

Don't have THE answer for you: but have questions: I have never seen a "white metal nut" on a basket strainer set. Now, is this nut "white" when new, and before you install it? OR-does it turn this "whitish" color after being on for the almost a year? IF it's turning the whitish color after being installed for some months this tends to lead me to believe you have a "galvanic" corrosion problem, caused by the interference fit of two dissimilar metals with some type of very small electrical current traveling between them. Probably too late to check this, but I'm wondering if you could actually see a difference in the threads of the nut before installing it and then after having it on for some months. If the threads appear to have been eaten away, then it is definitely galvanic corrosion. I would try to apply some Teflon based pipe dope to the threads of a new, clean, basket strainer before applying a new, clean, nut--even wiping some pipe dope on the internal threads of the nut. This may/should help with this problem.

GearHd6

Well I didn't actually mean white in color. I meant more like a pot metal or cast aluminum. I never really payed attention to the threads but they must corrode and round over I'd assume, the threads on the basket look fine. Maybe the pipe dope is the way to go? They're probably not the highest quality strainers seeing as they're from Home Depot. I believe they're Pegasus brand and weren't extremely cheap as they're about $35-$40 each. I see some nice ones from Kohler that run about $95.