I was doing some SS OEM Torx fasteners on my MC the other day & had this what I think was an unusual experience:
There were four involved & while I have mostly switched to the stick type of blue thread locker, I had a small tube of Permatex brand, blue liquid type & thought I needed to use it as had been around the shop for a good while-maybe 4-5 years. These are M5 threads on SS screws,clean,etc.. They were hand spun into brass female threads a good ways then I turned around to fetch my 1/4 drive ratchet, which was maybe 5' away at most. As I tried to turn them in they were essentially "locked up"! I could overcome the goop but was too hard.
Rest of story is that I contacted Permatex via email to ask the tech line the why it happened question.
Answer: It was that brass is an "active metal", no fault of the thread locker. It was never my intent to blame them but that was the tone of the response. Next email I made clear that I wasn't trying to score a $$$, just asking for a list of active metals/why it happened to lock so quickly,etc., & I get back a list of about all the metals you ever have heard of (w/o being a scientist & a periodicals chart!) other than maybe silver & gold. I sort of thought going into the question & having provided the tube code that I'd be told it was old material but no it was the active metal and it was suggested to use "purple thread locker" in the future. I have never bought purple thread locker(always red or blue in my tool box) but have a free sample coming.