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  • Cleaning Pots with WD-40?

    I need to clean some scratchy pots and does WD-40 work the best for this without spending a lot of money on Deoxit?

  • #2
    No. It will seem like it works while its still wet but it actually puts a film over the carbon and makes the issue worse.
    WD 40 is a moisture inhibitor developed for the Military and was used on weapons to prevent them from rusting/oxidizing.

    Don't use just any contact cleaner either. Many are zero residue alcohol based cleaners that will accelerate the wear on the carbon pad.

    Use only Lubricating type contact cleaner designed for pots. It has a cleaner and Mineral oil to lubricate the contacts so they don't wear and that crackle arching you hear is muffled down.

    You can buy the right kind of cleaner at Radio Shack or any electronics parts outlet.
    Or just order it on line. Here's some types that will work.

    http://www.parts-express.com/caig-de...m_campaign=pla

    http://www.sweetwater.com/store/deta...FeXm7Aod7QMAlw

    This is an example of the wrong stuff. http://www.mouser.com/ProductDetail/...FfHm7AodyjwAFg

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    • #3
      I read about Deoxit so I will give that a try. Good for Connections also. Thanks WR!

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      • #4
        I just used some Deoxit on a Vintage 1982 JCM 800 Marshall Combo and the jacks, and tube sockets were dirty. But now no static, crackling connections. Definitely worth $15 bucks!

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        • #5
          Good deal. Most pots are good for a couple of cleanings before they need replacement. Most of the time its just dust that gets in there on amps that collects on the contacts. Its not like you constantly dial the pots when you play through the amp. Guitar pots on the other hand get allot of use so the carbon pad inside tends to wear through more quickly. If the cleaner doesn't work, then the paper thin carbon pad is shot and no cleaner can fix that.

          Tube sockets should be cleaned with a non lubricating cleaner so there's less chance the sockets can arch out. High voltage tends to creep when any residue is left behind, especially when dust tends to collects later. They do however get hot so any lubricant left behind should evaporate fairly quickly. There's no need to redo it with non lubricating cleaner at this point, but you should know there are different cleaners for different parts. Tube contacts are more like switch contacts when it comes to cleaning and don't normally need a lubricant. The contacts usually just get dirty and oxidized and a straight alcohol cleaner does a good job on cleaning those. Plus with lubricant on there tubes will tend to get loose or possibly fall out with vibration. The alcohol tends to make the grippers hold the tubes in place better.

          Like I said, its a small point for future reference. You're amps working the way it should and that's good.

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          • #6
            I cleaned the preamp sockets only but will use the alcohol cleaner next time. Especially VI and V2 which tend to be static/crackly and it is better to use alcohol which is much cheaper anyway. Thanks WR!

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            • #7
              The ONLY cleaner I have found over the years that works reasonably well is CAIG DeOxit, a tiny amount only. I have seen enough totally destroyed pots that I would not recommend trying anything else. Also, linera faders can not be cleaned this way, too much rail lube gets washed onto the track which begins the deterioration cycle in ernest.
              -------------------------------------------------------------------------------------------------------------------------------------------------------------------
              Former product development engineer: Genz Benz, a KMC Music/FMIC/JAM Industries Company, continuing factory level product support and service for Genz Benz

              Currently product development engineer: Mesa Boogie

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              • #8
                Originally posted by agedhorse View Post
                The ONLY cleaner I have found over the years that works reasonably well is CAIG DeOxit, a tiny amount only. I have seen enough totally destroyed pots that I would not recommend trying anything else. Also, linera faders can not be cleaned this way, too much rail lube gets washed onto the track which begins the deterioration cycle in ernest.
                Yea some pots are packed with conductive grease to give the knobs a plush feel when turned. After about 10 years the grease dries out and turns to glue. Old Tapco mixers are an example of greased pots. I've done restorations of several. Anything alcohol based just makes the problem worse. I actually had to take every pot apart to degrease them, then repack them with conductive grease. Sprays including mineral oil wouldn't cut through the stuff. Not sure what they actually used. We called it oriental ear wax, but I suspect its silicone grease of some kind because nothing seems to completely remove it.

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                • #9
                  Damping lubricants are used in different places depending on the construction of the pot. Linear pots use a type of silicon grease on the side rails or on ground dowel guides, this kind of pot can not be cleaned because there's no way to keep the lube from migrating to the track when cleaner is applied. The ground dowel rail type can be rebuilt (assuming they have not been damaged by cleaner) by somebody with good tech experience and a steady hand, but the conventional inexpensive faders are probably cheaper to replace (though I have rebuilt some when the original part was NLA)

                  On rotary pots, the lube is contained in the shaft bushing as thrust washer assembly so using a TINY amount of Caig DeOxit will not cause lube migration. Regarding the Tapco pots, the lube used in those migrated all over the place on it's own and made a giant mess. Really, the only solution (other than replacement) would be to rebuild... hardly worth the effort given the market value of the units.
                  -------------------------------------------------------------------------------------------------------------------------------------------------------------------
                  Former product development engineer: Genz Benz, a KMC Music/FMIC/JAM Industries Company, continuing factory level product support and service for Genz Benz

                  Currently product development engineer: Mesa Boogie

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                  • #10
                    Sounds like DeOxit is the way to go. I always wondered what would work best.
                    One-stop source for price-efficient and DIY solutions for audio recording. Includes info on equipment, instruments, and also cool tutorials.

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                    • #11
                      FWIW department, along with a bit of rambling from me.

                      A couple of weeks ago, I played with one of my bands at a local restaurant slash watering hole. Small place, so I brought a small rig. Normally, I'd use my Sunn 200S head, but the last time I used it, I noticed the power tubes redplating, and I haven't got around to opening it up to look for the problem. I can be a bit lazy. So I took my Sentura II, a guitar head of similar vintage. Ran it through an old PA cabinet. JBL D130, and I've bypassed the horn, running the JBL full range. But when I first turned it on, and went to set the volume, the volume pot was scratchy. Really bad scratchy, like full output pops. But I found a good spot and set a nice volume. Sounded great in that small room.

                      Last night, I was playing a gig with a group that needed a bass player. A friend of mine usually plays with them, but he's busy and couldn't do it. This band stresses that they play at a pretty low level, so I thought I'd use the same rig. Room was larger, but I figured I'd be okay with the low level. But that scratchy volume pot might be a problem, so I went down to Radio Shack and picked up a can of DeOxit D5. I pulled off the knob. Didn't look as though there was any place to inject it, but I sprayed a bit around the shaft and worked it back and forth several times. Probably should have pulled the chassis and done this from the back, but I didn't give myself enough time. Besides, I'm lazy. Did I mention that?

                      Fired up the amp on standby, plugged in, and powered up. Nothing. Worried, I worked the volume knob back and forth, and got a very low level of sound. However, I noticed that the noise level changed, so I guessed that the problem was upstream. Bass? Cord? I've never had any issues with the bass, but cords being cords, I grabbed another. Problem solved!

                      And the volume control worked as if it were brand new. Perfect. I can personally vouch for using DeOxit as pot cleaner. Assuming that it doesn't have any bad results down the road.
                      "The Web puts all of the world's knowledge at our fingertips; unfortunately it's mixed with all of the world's bull****************."
                      -- Bob Parks

                      "A thing is not necessarily true because a man dies for it."
                      -- Oscar Wilde

                      "No man dies for what he knows to be true. Men die for what they want to be true, for what some terror in their hearts tells them is not true."
                      -- Oscar Wilde

                      "It is a trap of history to believe that eyewitnesses remember accurately what they have lived through."
                      -- Theodore White

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                      • #12
                        The pots they put in the older heads are usually good for a lifetime. The carbon pad is thick and they are built well.

                        Pots get scratchy because of dust. Most heads that don't have a fan use convection current to cool them. The heat of the head draws in air from the bottom and expels it from the top. This cools the chassis and components from the bottom but it also draws in a fair amount of dust and cigarette smoke which becomes tacky and the dust clings to the components including the inside of the pots. Working a pot back and forth can sometimes clear the carbon contact but when it gets bad they have to be cleaned.

                        The mineral oil and cleaners in deoxit remove trapped dust and film from the contacts. Zero residue contact cleaner has no lubricant and though it may temporarily work the stuff that created the film dries again and you're right back where you started. The mineral oil keeps the film from forming again.

                        WD 40 can be used on circuit boards. I've had many cases where liquids like coffee or soda got spilled on a board. You take the boar out wash it with soap and water, blow it off with and air compressor, then dry it with a heat gun/ hair dryer. Then you can treat the board with WD 40 to prevent moisture from penetrating and having the solder joints corrode. This is usually on older boards common in vintage amps that aren't sealed.

                        They have used sealants like lacquer and later some kind of poly sealant on newer boards to waterproof them and prevent corrosion. Its easy to tell which use lacquer. If you've ever used flux remover on boards to clean them up with a brush it makes the whole board tacky. When you get something with sugar and acid like coffee or soda, the acids eat at the lead solder and oxidize it and the sugar becomes a carbon conductor when its heated. Removing it all is very important. Pure distilled water on the other hand is a non conductor. Its the dirt salts and minerals in water that conduct electricity.

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                        • #13
                          Came across an interesting article today.
                          http://www.instructables.com/id/How-...our-Amplifier/
                          "The Web puts all of the world's knowledge at our fingertips; unfortunately it's mixed with all of the world's bull****************."
                          -- Bob Parks

                          "A thing is not necessarily true because a man dies for it."
                          -- Oscar Wilde

                          "No man dies for what he knows to be true. Men die for what they want to be true, for what some terror in their hearts tells them is not true."
                          -- Oscar Wilde

                          "It is a trap of history to believe that eyewitnesses remember accurately what they have lived through."
                          -- Theodore White

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                          • #14
                            Opening it up to clean it is fine, but a pencil eraser is a terrible idea. you wind up leaving bits of rubber behind which are worse then dust because they are highly non conductive. And if you don't lubricate the carbon pad, the brush will wear through the carbon pad in no time.

                            I'd modify that procedure to removing the residue with denatured alcohol and a lint free cloth. Then apply a thin film of mineral oil so the contact brush doesn't wear through any more than it has. In cases where the pots are really unique, I've bent the brushes over slightly so they ride on the pad in an unused spot and you can get twice the lifespan out of the pots. Its a tricky operation avoiding breaking the brush tips so you want to use some fine tweezers or hemostats and just tweak them a tad for that.


                            Another item is you can do this many times without unsoldering the pot from the wires or PCB. If they are chassis mount you can often extract the pot and have enough room to remove the can leaving it connected. Other times you can get the can off and leave the carbon trace soldered to the board. I've done many Tapco mixers this way where you have like 40 pots that all have to be dissembled because thay were originally packed with conductive grease. The grease dries out and turns to chewing gum so you have to dissemble every pot to remove that gunk with a petroleum based cleaner then repack then with conductive grease. Its a nightmare of a job, but its the only way to restore those old work horses.

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                            • #15
                              On the heels of my earlier success with the DeOxit, I next tackled my power amp. I use that with a Peavey T. B. Raxx preamp. Best low end I've ever had. But the pots on the power amp were dirty, and it wasn't always easy to find a good spot such that the amp worked properly. So I took off the lid, cleaned out the sawdust and spiderwebs inside, then sprayed the DeOxit into the pots and ran them through their ranges many times. Worked great at last night's gig.
                              "The Web puts all of the world's knowledge at our fingertips; unfortunately it's mixed with all of the world's bull****************."
                              -- Bob Parks

                              "A thing is not necessarily true because a man dies for it."
                              -- Oscar Wilde

                              "No man dies for what he knows to be true. Men die for what they want to be true, for what some terror in their hearts tells them is not true."
                              -- Oscar Wilde

                              "It is a trap of history to believe that eyewitnesses remember accurately what they have lived through."
                              -- Theodore White

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