What to use on "dirty" pots.

[roknjohn]

Didn't find much using search function. What would be your first choice for cleaning dirty or noisy pots?

Thanks

[keninverse]

Ahh...the eternal dirty pot question...
I say replace it.  Otherwise you can take it apart and clean with 99.9% isopropanol followed by a decent lube like Cailube.  If you just spray the pot with something like deoxit you're not really cleaning the pot.  Also make sure you don't use anything abrasive to mess up the tracks.




ken m.

[The Tone God]

Don't use a non-lubricating cleaner like contact cleaner. It can dissolve or wash away the lubricant that may already be in the pot making it even worse sounding and harder to turn.

Andrew

[Mark Hammer]

Pots can behave intermittently for a number of reasons:

• intermittent contact between the solder lugs and the resistive element
• Intermittent contact between the wiper and the resistive element
• Intermittent contact between the wiper and its commutator (the metal thing the wiper touches as it moves around

Those intermittents can be caused by:

• loose rivets holding the solder lugs to the resistive element
• corrosion of the wiper
• corrosion of the commutator
• material/dirt/non-conductive deposits covering the resistive element

Clearly the causes of malfunctioning pots can vary, as can the "cures".  Here's what I started doing to rehabilitate my pots.
1) I pop the back covers, making sure not to bend the tabs so much that they isk breaking when re-assembling.
2) I wipe any grime off the resistive element with a dry Q-tip.
3) With a pair of needle-nose pliers, I give each of the 3 rivets holding the solder lugs a gentle-but-firm squeeze.  I suppose if you have the "right" pliers youcan do this without lifting the back off, but I find I can do it at a suitable angle in a less risky fashion if the back is out of the way.
4) If it's REALLY dirty I might apply some isopropyl alchohol and really give the resistive strip a good cleaning with a Q-tip.
5) I apply a few teeny drops of Stabilant ( http://www.stabilant.com/ ) contact enhancer.  I move the wiper so that it is at its "starting point" and place adrop just ahead of it then move the wiper back and forth so that the fluid spreads as far along the element as it can.  Then I move the wiper up to the dry spot and place another drop with the applicator.  Three drops (and these are VERY small drops) is usually sufficient for small pots.
6) In rare and extreme cases (e.g., VERY old pots), the wiper might need retensioning.  Here you might use some fine dissecting tweezers to slightly bend the "fingers" of the wiper towards the resistive element.  Keep in mind the wiper is essentially a leaf-spring that stays in pressure contact with the resistive element.  It has to "want" to press against the resistive strip.
7) Put the cover back on and away you go.

I am constantly surprised by how many pedals that had given me unending grief suddenly sprang back to life when the conductive weaknesses in the pot contacts were addressed.  A buddy with a very busy knob-intensive mostly-analog studio had recommended this Stabilant stuff to me, and though I used to be a contact-cleaner spray-can guy, I'm converted.  They oughta call it "Crackle-be-gone".  I buy it from a local electronics retailer in 50-cent "sampler" vials with 1.5CC or something like that, though you can get it in bigger containers for the price of perfume. I find one vial generally lets me repair about 20-30 pots.

[roknjohn]

Well I tried taking the pot out, but the knob is on so tight, I felt if I put any more pressure on it I might pull the shaft right out of the pot. So before I go any further I figured I would try giving it a squirt with something first, and see if that got things back to normal. If that doesn't do the trick I may have to order a replacement to have on hand before I try to pull the knob off and replace the pot.

Mark, I checked out the product you recommended. Interesting, I have never heard of this product, but would like to try to get my hands on some. Web site says they don't do credit card orders. If I can't get a hold of some by other means, would you be interested  in bartering for a small vial?

Thanks all for your input.

[Mark Hammer]

Drop me a PM.