Scratchy Volume Pedal Pots Can Be Cleaned

Nick Reed · Post by **Nick Reed** » 8 Jun 2006 9:55 pm

First off, a super big thanks to my friend Big John Bechtel for telling me about this little trick

When my old Emmons Volume Pedals would get scratchy, I had always replaced the pots. This can get pretty expensive, not to mention being able to find Clarostat replacements. I get so tired of others telling me to buy a new Hilton when I prefer my old conventional ones. Anyway, John told me how you can remove the cover on the pot and clean it with high quality electronic contact cleaner. I got some CAILUBE MCL cleaner and I'm here to tell you IT WORKS! I had 3 old pots I had saved over the years, I cleaned them and now they're once again usable. Thank you, John your the best. NR

Tommy Roten · Post by **Tommy Roten** » 9 Jun 2006 12:25 am

WD-40 works too, I've used it lots of times.

Post by **Dave Mudgett** » 9 Jun 2006 2:03 am

Yep, that's a useful trick if the scratchiness is caused by long-term wear. I also like my Goodrich 120 pedals. This is getting to be more and more of an issue, as the quality of new replacement pots appears to be deteriorating.

Many pots, especially the older ones in guitars, have vent holes specifically to shoot cleaner in. But higher quality mil-spec pots like the ones in the good volume pedals are often sealed to keep the dirt and dust out. In order to clean them, it's necessary to very carefully remove the cover, clean, and then reassemble. I like Caig CaiLube MCL (now called DeoxIT Fader Lube) for carbon-comp potentiometers and Caig DeoxIT D5 for metal contacts like switches.

This article deals with the potentiometer in a servo assembly, but the photographs of the steps related to disassembling and cleaning the pot are relevant: http://www.rcyachts.com/Build/servorepair.htm

Different pots have different ways to open up the cover, one needs to carefully look it over and see how it works. When you're inside the pot, you need to be careful not to damage the wiper. Usually, I just leave it alone, but sometimes the wiper isn't making good contact. In this case, I try to re-tension the wiper on the conductive surface, but it's easy to mess it up.

But before I open up a sealed pot, I try to restore normal operation by putting the pot through its full travel many times - it may take a lot of sweeps to remove the oxidation causing the scratchy sound. As this article http://www.steelguitarinfo.com/other/volumepedal/pot_goodrich.html states, scratchiness can be due to just sitting idle for a period of time. If that doesn't work, there's no option but to open it up and try to clean it.

Also useful is this article on replacing the pot and string in a Goodrich-style pedal: http://www.steelguitarinfo.com/other/volumepedal/pot_change.html

Jack Stoner · Post by **Jack Stoner** » 9 Jun 2006 2:04 am

"Cleaning" can help if the pot is not worn out. But if the resistance strip or the wiper pad is worn out there's nothing you can do to revive it.

As an amp tech, I don't regret dumping the pot pedal for a Hilton, two years ago. [This message was edited by Jack Stoner on 09 June 2006 at 05:03 AM.]

Post by **Dave Mudgett** » 9 Jun 2006 2:08 am

"I may be worn, but I ain't worn out." WJ

Yes, the conducting element or wiper do eventually wear out, but it may be possible to fix a pot with some wear.

John Daugherty · Post by **John Daugherty** » 9 Jun 2006 5:38 am

Wanna learn some new words?
Take the cover off of a pot in the Ernie Ball pedal and try to put it back on.
This pot is wire wound on a piece of thin flexable plastic.
After trying to clean the Ernie Ball pot for a friend, we found ourselves headed to Ozark, MO. We came back with a Hilton pedal.

------------------
www.home.earthlink.net/~johnd37

Post by **Dave Mudgett** » 9 Jun 2006 7:31 am

Yes, one needs to just replace the EB pots. When I used an EB pedal for guitar, I just ordered the replacements (through my shop) directly from EB. We always kept one or two around - lots of local guitar players use the EB pedals. I think it's still possible to do that, but I didn't see any web sources for the mono volume pots. They aren't exactly cheap, but I always found they lasted a long time.

What Nick's talking about is for carbon composition potentiometers, like on a Goodrich 120.

John Bechtel · Post by **John Bechtel** » 9 Jun 2006 11:13 am

Thanks, for your thanks, Nick! Just for the record, I use a product in a spray~can called “Lube~Job” Electronic-Cleaner & Lubricant, from a Co. out of Fla. I think, nowadays Pots get scratchy way before they have time to wear out from ‘years’ of use! How long would you have to play 24/7 to actually wear out a Carbon~Pot? Quite a while!
------------------
“Big John”
a.k.a. {Keoni Nui}
Current Equipment
[This message was edited by John Bechtel on 09 June 2006 at 12:14 PM.]

Donny Hinson · Post by **Donny Hinson** » 9 Jun 2006 4:46 pm

Many times, the noise in a pot comes not from a worn resistance element or block, but from the brass fingers on the inside (near the shaft). These fingers (there are 2) are the contact from the wiper block to the pot terminal. They get dirty, and can make noise too. I've seen the little carbon blocks in the wiper wear down, but I've never seen significant wear on the resistance element itself.

New pots should be lubed before they're installed or used! I don't recommend WD40. It will work for awhile, and then cause other problems (like corrosion and gumming) a few years down the road.

Clyde Mattocks · Post by **Clyde Mattocks** » 9 Jun 2006 9:34 pm

This has been raised before, but I drill a
small hole in the metal cover near the bottom
of the pot, being
careful not to get shavings inside, and spray
in some Radio Shack contact cleaner/lubricant. I usually get several months extra life out of a pot this way.
Sometimes it doesn't work, but it's worth
the effort when it does.

Ray Uhl · Post by **Ray Uhl** » 9 Jun 2006 10:37 pm

I'm with you Clyde!! Been doing it that way for 40 years. However, I went with a Hilton, but do miss the convience of not having to mess with the bulky power supply chord.

Jack Stoner · Post by **Jack Stoner** » 10 Jun 2006 2:06 am

Drilling a hole, even a very small hole, defeats the purpose of having a "sealed" pot. If you are going to drill a hole you may as well use a standard pot, not the "mil grade" sealed pots.

Donny Hinson · Post by **Donny Hinson** » 10 Jun 2006 4:07 am

Jack, the "sealed" aspect isn't the only advantage to Mil-grade pots, they have better parts all around than ordinary (consumer-grade) pots.

That said, drilling a hole in the pot is just as much work as removing the cover. I'd rather remove the cover to fix a pot, because that's the only way to get it really clean.

Donny Hinson · Post by **Donny Hinson** » 10 Jun 2006 4:09 am

Nick, the "pot cleaning" threads come up here at least a couple of times every year. I'm surprised you missed all of them.[This message was edited by Donny Hinson on 10 June 2006 at 05:12 AM.]

Jack Stoner · Post by **Jack Stoner** » 10 Jun 2006 5:06 am

Donny, I know about the Mil Std for pots, having worked in Electronics in the military and with the even higher standards in NASA. I was trying to make a point about putting a hole in them. I guees it didn't come across right.

Clyde Mattocks · Post by **Clyde Mattocks** » 10 Jun 2006 6:59 am

To further beat a dead horse, the point to drilling the hole is you only have to it
once, whereas removing the cover, you must
do it each time. Spraying cleaner thru the hole may work for several times.

Jim Sliff · Post by **Jim Sliff** » 10 Jun 2006 7:59 am

"WD-40 works too, I've used it lots of times"

Never, ever use WD40 on a pot. It has components that will form a resinous gum, destroying the pot. Electronics techs constantly make money replacing pots where folks have used WD40. I can't stress this enough - it WILL destroy the pot.

Also - please do not use the word "cleaner" - it might lead someone the wrong way. The stuff the original poster used is a "cleaner/lubricant" - and the ones made specifically for electronics are usually fine. Bu there MUST be a lubricant component, or again - you destroy the pot. It will wear out extremely fast if you just use a cleaner.

Caig makes the best stuff IMO. CAILUBE MCL is a Caig product. Deoxit Gold is another good one from Caig.

WD40 is good for garage door springs and wheelbarrow axels. It should never touch a guitar or amp. Ever.