Jim Wilkins wrote:
"Gunner Asch" wrote in message
...
On Thu, 6 Apr 2017 13:34:05 +0000 (UTC), unk wrote:

I would like to be able to tell by colour if a screw has turned -
does
that exist?

Low-strength/removeable...

Maybe a kind of varnish?
Fingernail polish works nicely as both a thread locker that will
allow
the screw to be removed easily without extra effort, and it will
show
if the screw has been removed or moved.

Works better than "locktite" for gun applications. And you can get
it
cheap from the missus or the discount store.

Have a good story ready for why you need it. I've found it in all the
electrical coding colors, some of which would be really weird on
fingernails.
-jsw



Used it a lot when I did electronics repairs. I used a real ugly green.
Made it easy to tell if I had worked on an item before and if the part
had been touched by someone else.

For the OP, I've not seen a single coating that changes that way, BUT if
you put a small dot of the paint at the junction of screw/part. it would
show up if the screw was moved because the coating would be broken and
shifted.
Another option would be a simple index mark, like using a sharp scribe
across the end of the screw and up the interior of the hole.
Misalignment means the screw has moved.

--
Steve W.