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I have a couple of potentiometers that haven't been touched in quite some time. In fact, probably not in 15 years. So now they produce noisy output, presumably from oxides or some other crud that has built up on the contact surfaces.

Outright replacement might be an option, but these are quite large relative by current standards, they are in fact about the diameter of a quarter and are probably 1/4" inch thick, real 1970's technology. Might be hard to get the same form factor.

Certain retailers used to carry this stuff that came in a can like wd-40, complete with a little red tube for injecting the stuff into exactly this kind of part. You'd squirt a tiny amount into the noisy pot, wiggle the knob 2-3 times, and no more noisy output. So there's the proof of concept that it can be done, but this magic stuff seems to have vanished from the shelves.

It had to just be some kind of solvent, like xylene or something. Any ideas on what would clean the corrosion (dust? dirt? fungus?) off a potentiometer, without damaging it?

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14 Answers 14

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Just spray contact cleaner on it and wiggle it back and forth. :)

It hasn't vanished:

DeoxIT http://www.google.com/products?q=contact+cleaner

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    \$\begingroup\$ i thought that it must have been banned for burning holes in the ozone, but it's nice to see 'CFC free' on those. \$\endgroup\$ – JustJeff May 6 '10 at 3:57
  • \$\begingroup\$ In fact, I just got my own bottles of DeoxIT at Radio Shack. :) \$\endgroup\$ – endolith May 8 '10 at 22:51
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    \$\begingroup\$ I used to use deoxit when I used to work on some old Army radars from the 60s. They were man-portable, and so were always getting exposed to water, mud, diesel fuel, weapon cleaning oil, and whatever else was in the area. That stuff works like magic on internal and external connectors as well as pots! \$\endgroup\$ – Jesse Jul 20 '10 at 17:02
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I have used CRC Electronic Contact Cleaner, to just plain old Windex to clean potentiometers.

It doesn't really matter that much what cleaner you use, provided that it doesn't leave behind any film. So I wouldn't use WD40 or anything that says that it lubricates.

  1. Soak it by spraying it with your favorite cleaner.
  2. Rotate it several times.
  3. Spray it some more to get anything that broke loose out.
  4. Repeat steps 2. & 3. as necessary.
  5. Let it dry completely.

After you have cleaned it you should put in some dielectric grease.

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  • \$\begingroup\$ CRC is available at many automotive supply stores (Advance, Napa), and is cheaper than the Radio Shack stuff. \$\endgroup\$ – Kevin Vermeer Jul 8 '10 at 14:22
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Isopropyl alcohol works well too - You can submerge the pot and give it a good soaking, then just turn the wiper backward and forward a few times to make sure it's well worked in. Then just leave it to dry before turning the electrical equipment back on.

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I don't know if I'd say it's vanished... in the US, at least, I've seen DeoxIT at Radioshack and Fry's Electronics carries a couple of types of electronics cleaner.

I picked up some stuff (not DeoxIT) that did a cleaning, but it didn't last very long (maybe a couple of months). Deoxit is better, I hear. I was cleaning potentiometers in a 1970s Marantz amplifier.

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    \$\begingroup\$ Actually I used DeoxIT on my scope and it didn't "last", either. I seem to remember it working well after I used it, but it's back to being intermittent now. Hmmmm \$\endgroup\$ – endolith May 6 '10 at 13:54
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I picked up a can of Control/Contact Cleaner and Lubricant at Radio Shack tonight. It was a 4.5 oz. can for around $11.00, a bit pricey, but it should do the trick.

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    \$\begingroup\$ We prefer you not add signatures and a prefix to your answer. That's what the user badge right below your question is for. Since you seem to be an unregistered user, I removed them for you. \$\endgroup\$ – Connor Wolf Jan 2 '12 at 2:54
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By all means, clean and lubricate the potentiometer.

However, a pot in an audio circuit should not make any significant scratching noise.

Scratching noise is a sign of a possible design neglect in the circuit: namely, a DC potential across the wiper contact. Quiet operation is ensured by allowing only AC signal through the pot.

Even a brand new pot, especially a cheap carbon one, will make scratching noises if DC is flowing through it.

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  • \$\begingroup\$ Do you have a link that explains the AC method that you are describing? \$\endgroup\$ – Bort May 4 '18 at 18:06
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I'd like to throw my support behind the answers which recommend isopropyl alcohol, as I have had excellent results.

In my case, I used a mixture of 91% isopropyl alcohol and acetone (2:1 alcohol to acetone ratio) which I got from my supermarket (totaling 48 fl oz for about US $6.) This originally was to make flux remover, but I discovered it also makes a GREAT contact cleaner!

I bought an old 70's era cassette deck for parts, which had a very nice dual concentric pot (recording level), but was no longer usable since it was horribly scratchy. After soaking overnight (use a jar with tight lid), it was in perfect like-new condition! I wouldn't try to say this cleaner is BETTER than a particular commercial contact cleaner, but for a convenient high performance/low cost option it's hard to beat.

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You can just clean it with WD40 and then, find a hole on the body (usually it has one!), so put some silicone grease inside, it´s a good lubricating and it´s clean.

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  • \$\begingroup\$ WD-40 works initially, but eventually after the volatile end up in the air, all that's left is a sticky mess. Not really good for electronics. \$\endgroup\$ – Bryce Jun 17 '19 at 15:02
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A little 96% alcohol dripped into the pot, twisting the shaft a few times, then drying the excess with a hairdryer - worked wonders for me.

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suggestion for cleaning corrosion off pot contacts,glaziers have used pumice,,extremely fine powder used to clean tiny dirt specks from pitted new & old glass,using a bit of the powder ( also termed 'rubbing compound' on a q-tip, moistened with isopropyl alchohol,,canned air to blow out residue after drying,,watch the nephew doesn't blow on the open container,get in the eyes & irritates. the conducting surfaces ,,copper,,silver ought to look polished & clean.

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    \$\begingroup\$ Not the contacts; the track. To use abrasives on it will surely destroy it, not to mention that it is not readily accessible to clean it in this way. \$\endgroup\$ – Oleksandr R. Jun 21 '15 at 0:50
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Came across this post looking for appropriate solutions to clean a scratchy potentiometer I had on a high-powered home amplifier.

I used a alcohol based screen cleaner spray I had set aside since I couldn't find anything reasonably cheap or adequate to use around the house.

After using this screen cleaner over the past year, since it's alcohol based it evaporates at a reasonably fast rate which is quite suitable. I sprayed the pot a couple times without opening it, gave it a couple turns to loosen any dust and dirt, let it dry and it's working like a charm.

Would recommend it over other solutions, Windex can be a little tricky to use and it will leave some chemicals behind which might influence the life span of your pot. (But hey, if you want some lavender scented variable resistors, I'm not one to judge)

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it's pure carbon thin layer on phenolic resin substrate, gee take a bad POT apart once and see that. its not a commode pot, its not to go potty in, as other posted. clean it with pure alcohol. never use acetone on most plastics for sure this one. if you read the specs on phenolic resins it says that exactly and why damage happens. rubbing alcohol has oil in it, The pro grade does !, avoid oil ! avoid grease except the shaft bushing. the pure carbon does not oxidize. it just does 2 things. wears out (no cure there) once the carbon path of the gold wiper hits resin ! and gets dirty, clean it with alcohol is best. pure, as near as possible cheap alcohol has 1% water while ok delays drying a long time. (can) retired long time tech, 1965 to 2009, and mil trained, on this. Pots can be bought new if not too complex. 3 lug easy, even 6 lug dual. no switches. they come on linear and Log types. volume controls are log. end school. be happy if it works 1 year.

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    \$\begingroup\$ Welcome to stackexchange. As this is not a forum, the answers here are expected to be of high quality. This requires basic proof-reading. Are you able to easily read your own answer? Your post has incorrect capitalization and punctuation, is in need of complete sentences, and is comprised of one giant paragraph with little organization. \$\endgroup\$ – Bort Jan 9 '18 at 18:14
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Just used Disc brake cleaner on my stereo receiver.

Worked great. Let it dry after you twist it wet.

My balance control was out. Came back to life.

bill

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