$keywords = "tech tips,tech tip,lbrty4us,pots,potentiometer,clean,cleaning,pot cleaning,cleaning pots,scratchy pots,noisy pots,noise,sockets,arc.arcing,switches";
$title = "Possible Risks of Spray Contact Cleaners";
$tech_tip = 'Authored 02/03/04
<P>
Over the past couple years, I\'ve run into some serious concerns that have
come back to haunt me with some of my own gear that I\'ve used the usual
name-brand spray products on.  Most of this gear is not guitar-related,
but may or may not have implications for servicing amps.

<H3>Tube sockets:</H3>

I\'ve noticed a pattern of carbon-tracking failures requiring replacements
of phenolic or other plastic sockets sprayed with a contact deoxidizer
long before-- and no similar failures on others not sprayed.

<H3>Rotary or gang-latch fiber or phenolic switches:</H3>

Ditto, and with some catastrophic results.  I checked around with a few
other guys on this, and proved one of them right who said:  "You haven\'t
lived until you\'ve replaced the test switch in your TV-7."  I would
suggest, don\'t ever spray a contact cleaner on such a switch, or allow any
to run over it or into it.  And if you do by accident, you may not be able
to decontaminate it even if you take it out &amp; wash it in solvent.  It
seems that some will decontam &amp; some won\'t.  I\'d rather not find out
anymore.
<P>
Based on the above, I will now only apply such things with a toothpick or
needle to an exact spot where they are really needed.  Also, many better
sockets and switches have contacts plated with silver or beryllium, and
the oxide is as conductive as the base metal &amp; is protective of it. 
"Clean" does not always mean "deoxidize", and many are not dirty in the
first place.  If it ain\'t broke, don\'t fix it "so it won\'t get noisy."  As
far as tube sockets go, most can be "tightened" rather than sprayed if
they are intermittent.  If a contact is too shot or problematic, consider
replacing the socket instead of contaminating it.

<H3>Pots:</H3>

I used to use a fairly mild, cheapo TV tuner-type spray judiciously on
pots, and it worked fine for regular maintenance unless the pot was about
ready for replacement.  I have also hit pots &amp; switches with auto brake
cleaner (trike) in a pinch with no ill effects, but it can be deleterious
to other nearby components.  Many pots I\'ve used the better &amp; famous
cleaners on have had a shortened service life.  Pots, even the more
expensive ones now sold, aren\'t as robust in the carbon thickness &amp;
contact-plating departments as older ones were, and appear to wear much
faster with these cleaners.  Of course, some of the pots in an old amp are
already worn thin.  I have now decided to only spray this stuff on pots
that have to go right back to work for awhile and that will be
unacceptably noisy otherwise in real-world playing or performance, when
the mild stuff doesn\'t do it &amp; replacement isn\'t immediately practical. 
If a Reverb pot is noisy only at 8, I leave alone because it will never go
there.
<P>
I\'d also suggest, don\'t get any of this stuff on your tube tester\'s
sockets, or socket savers, if you use them.  In one instance, the
resultant tracking on a saver also hosed the socket, saving nothing and
making a lot of unexpected work in a crowded tester chassis. Socket savers
also have gotten expensive, and without any spray, other contamination can
get between saver &amp; socket &amp; cause the same problem.
 If you use them, keep your tester as clean as a lab instrument &amp;
always closed when not in use, unless you like changing out sockets. I
don\'t use them anymore because of the contamination risk.  You\'d want to
treat your tester like this anyway if you\'ve carefully calibrated it.
<P>
I haven\'t had any problem with glazed ceramic sockets &amp; switches. Yet. 
But I haven\'t sprayed many, either.
<P>
These things are harder to deal with in tight, complex gear than in a
simple &amp; spacicous guitar amp, but are passed on to the extent they may be
relevant.
';

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