[Elecraft] Loctite

[Ron D'Eau Claire]

Loctite also has some nasty effects on certain plastics.=20

I had an old Optivisor with a screw holding the old-style lens plate =
that
kept falling out. This was back about 1985 or so. I was working in a =
Land
Mobile radio repair shop and grabbed some loctite to secure it and end =
the
problem. I don't recall, but in my haste I may have smeared some excess =
onto
the surrounding plastic and simply wiped it off.=20

For the next six months, the plastic hood of the Optivisor slowly
disintegrated, starting from where I had put the loctite on the screw. =
The
plastic grew brittle, then weak, then simply fell apart. I was able to =
grab
some epoxy to refill the gaps left by the breaks, but the disintegration
continued around the edges.=20

Finally, after about 2 inches of the plastic disintegrated, the process =
came
to a natural halt. I still have that pair down in the shop, patched with
pieces of PC board epoxied over the gaps in the original hood!=20

I have never used loctite on anything again!=20

I HAVE used a drop of thin "super glue" on threads of screws I don't =
want
coming loose. The thin stuff is best so it "wicks" along the threads and
doesn't get on the surrounding surfaces. It holds the nut just fine, but =
it
isn't so strong that I can't remove the nut with a little tug from a =
wrench
to break its grip.

Ron AC7AC

-----Original Message-----
A word of warning to anyone who uses Loctite (tm).  My experience in =
auto
mechanics has tought me  to use BLUE loctite on the threads of something =
you
may need to remove (service).  NEVER use RED loctite on the threads of
something you ever want to remove (never overestimate your desire to =
"never"
want to remove something).  I can not speak to using RED loctite it as a
"drop lock" on trimmer caps or resistors or how it compares with using
superglue in similar situations.

dt
.