Frozen Setscrews

[Jim Strohm]

 Ron Evans <cosmos41 at IX.NETCOM.COM> sez:

>HELP!
>
>Five simple plastic knobs on a Hallicrafters SX-130.  Held to their
>shafts with a slotted setscrew (not allen head).

   [snip]

A commonly available scouring powder called ZUD contains enough
of a phosphoric acid-based chemical that it can dissolve rust.
The major marketing point of ZUD is that it removes rust stains.

A paste of ZUD and water, or ZUD and WD-40, can sometimes work
amazing feats on loosening long-frozen parts.  Although I have a
whole lot of other tricks in my bag for this problem, I always
keep ZUD on hand.  My best ZUD experience was when I used it to free
up a ruptured brake line on my '79 Chevy 1-ton truck.  A previous
owner had used it extensively in snow country, and a LOT of screws
were rusted beyond the point of repair.

Ten cents' worth of ZUD and a little bit of patience saved me a
$50 tow bill and a multi-hundred-dollar repair bill to replace
a $15 brake hose.

Although ZUD works best on iron deposits, it also has some effect
on other compounds commonly found in drinking water such as calcium,
magnesium, etc.  For these, Lime-Away (another trick in the bag)
works better.

Jim N6OTQ

P.S. Ask me what I learned to do with a hot air paint stripper gun!