Contact cleaner vs alcohol

[Alley_Cat_Jack]

So I have a few old analogue oscilloscopes that need some maintenance and repair. After looking around online on what people use to clean pots and switches, I have found many answers. Those include the horrible idea of using WD-40. What is the consensus here on what is best and safest for the machine to use?

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[Jeroen3]

Contact spray is an acid that will eat away the oxidation, and eventually the contact itself.
Don't use that, since the device will become addicted to it.

I do not know if WD40 is acidic.
You want to use a neutral lubricant to protect it from oxidation and help sliding. As often found on CEEE plugs when they are brand new.
Obviously not a flammable one.

[Alley_Cat_Jack]

Will alcohol safely remove oxidation then?

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[AF6LJ]

Will alcohol safely remove oxidation then?

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Alchol won't remove oxidation without some elbow grease.
Silver Oxide is conductive and rarely presents a problem on switch contacts.
I use Alchol or other solvents for general cleaning. On switches and connectors I use Deoxit sparingly. 

[tautech]

Will alcohol safely remove oxidation then?

Not as such, however with switch/pot exercise and IPA (alcohol) you can improve things.

Deoxit seems to be the favoured product on the forum.

[Fsck]

Will alcohol safely remove oxidation then?

Not as such, however with switch/pot exercise and IPA (alcohol) you can improve things.

Deoxit seems to be the favoured product on the forum.

they have good products for flushing and for coating.

other companies also offer good (and often cheaper) cleaners as well. you're usually aiming for some kind of alkane blend for flushing. then, potentially a product with a lubricant of some sort for long term application.

[timb]

Will alcohol safely remove oxidation then?

Not as such, however with switch/pot exercise and IPA (alcohol) you can improve things.

Deoxit seems to be the favoured product on the forum.

they have good products for flushing and for coating.

other companies also offer good (and often cheaper) cleaners as well. you're usually aiming for some kind of alkane blend for flushing. then, potentially a product with a lubricant of some sort for long term application.

The DeoxIT in spray cans is basically 5% D100 and 95% Isopropanol Alcohol, plus aerosol; this used to be called DeoxIT D5.

 I don't buy that anymore, instead I get the glass bottles of D100 (which is 100% DeoxIT) with the brush applicator (like a fingernail polish bottle) and make my own D5. Here's how:

I use 20ml glass bottles with the droppers built into the cap. I add 1ml D100 and 19ml of 91% Iso Alcohol. Shake throughly! This ends up being a 5:95 mix, just like the spray cans.

I also make up bottles of DeoxIT Gold and Shield the same way.

I use a 1ml syringe to inject the D/Iso mix into ganged push button switches from behind (inject some, operate switch, repeat) using about 0.2ml per switch. After this, let it dry for about an hour, then operate the switches for a few minutes each; this will break up any remaining oxidation. Flush with 91% Iso, blow the switches out from behind with canned air and finally, give each switch a 0.1ml shot of the D5 mix; operate each switch once or twice after injection to make sure both sides of both contacts are coated (if it's >=DPDT switch). Now, let it dry. The alcohol will evaporate and leave some DeoxIT as a coating.

For rotary switches, I use the D5 mix with the eye dropper. Basically you just coat each wafer with it and keep turning the switch. After about 10 minutes, spray it off with 91% Iso, turn the switch some more, spray again and let it dry. Then apply D100 to a foam swab applicator (Swab-It brand works well for me; *do not* use cotton applicators like Q-tips, they'll leave lint everywhere) and use it to gently scrub the metal discs on each wafer. The applicator will turn brown as it removes oxidation. Then apply a tiny drop of D100 to *each* contact on the wafer (the contacts are U shaped; the edge of the metal disc slides between them as it rotates) and work the switch for a few minutes. Wipe off excess with a clean foam swab.

You should also lubricate the ball bearings of the rotary switch. White Lithium Grease works well, but if you use it, do *not* use the canned aerosol type. It gets *everywhere* and you don't want it on the switch contacts or discs! The same applies for Silicone based spray lubricants. If you use White Lithium Grease, get a tub of it and apply it sparingly with a toothpick.

What I use is Hoppe's Number 9 with a Precision Needle-Tip Applicator. It's a mineral based lubricant that doesn't gum up or dry out. If it's good enough to keep the slide of my H&K USP working perfectly after putting 200 rounds down range, it's good enough for the bearings of a rotary switch! (It's seriously good lube. I use it everywhere; locks, hinges, reels, etc.)

[Alley_Cat_Jack]

Will alcohol safely remove oxidation then?

Not as such, however with switch/pot exercise and IPA (alcohol) you can improve things.

Deoxit seems to be the favoured product on the forum.

they have good products for flushing and for coating.

other companies also offer good (and often cheaper) cleaners as well. you're usually aiming for some kind of alkane blend for flushing. then, potentially a product with a lubricant of some sort for long term application.

The DeoxIT in spray cans is basically 5% D100 and 95% Isopropanol Alcohol, plus aerosol; this used to be called DeoxIT D5.

 I don't buy that anymore, instead I get the glass bottles of D100 (which is 100% DeoxIT) with the brush applicator (like a fingernail polish bottle) and make my own D5. Here's how:

I use 20ml glass bottles with the droppers built into the cap. I add 1ml D100 and 19ml of 91% Iso Alcohol. Shake throughly! This ends up being a 5:95 mix, just like the spray cans.

I also make up bottles of DeoxIT Gold and Shield the same way.

I use a 1ml syringe to inject the D/Iso mix into ganged push button switches from behind (inject some, operate switch, repeat) using about 0.2ml per switch. After this, let it dry for about an hour, then operate the switches for a few minutes each; this will break up any remaining oxidation. Flush with 91% Iso, blow the switches out from behind with canned air and finally, give each switch a 0.1ml shot of the D5 mix; operate each switch once or twice after injection to make sure both sides of both contacts are coated (if it's >=DPDT switch). Now, let it dry. The alcohol will evaporate and leave some DeoxIT as a coating.

For rotary switches, I use the D5 mix with the eye dropper. Basically you just coat each wafer with it and keep turning the switch. After about 10 minutes, spray it off with 91% Iso, turn the switch some more, spray again and let it dry. Then apply D100 to a foam swab applicator (Swab-It brand works well for me; *do not* use cotton applicators like Q-tips, they'll leave lint everywhere) and use it to gently scrub the metal discs on each wafer. The applicator will turn brown as it removes oxidation. Then apply a tiny drop of D100 to *each* contact on the wafer (the contacts are U shaped; the edge of the metal disc slides between them as it rotates) and work the switch for a few minutes. Wipe off excess with a clean foam swab.

You should also lubricate the ball bearings of the rotary switch. White Lithium Grease works well, but if you use it, do *not* use the canned aerosol type. It gets *everywhere* and you don't want it on the switch contacts or discs! The same applies for Silicone based spray lubricants. If you use White Lithium Grease, get a tub of it and apply it sparingly with a toothpick.

What I use is Hoppe's Number 9 with a Precision Needle-Tip Applicator. It's a mineral based lubricant that doesn't gum up or dry out. If it's good enough to keep the slide of my H&K USP working perfectly after putting 200 rounds down range, it's good enough for the bearings of a rotary switch! (It's seriously good lube. I use it everywhere; locks, hinges, reels, etc.)

Wow, thanks for the guide. Any suggestions on where to get all of this?

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[Len]

Wow, thanks for the guide. Any suggestions on where to get all of this?

Deoxit is available from Active Tech www.active123.com - if you live in the right part of the country there's a store near you.

[Alley_Cat_Jack]

Wow, thanks for the guide. Any suggestions on where to get all of this?

Deoxit is available from Active Tech www.active123.com - if you live in the right part of the country there's a store near you.

Right part of the country, hmm? *looks outside and sees nothing but trees* nope. Lol

I live about 2.5 hours drive from the nearest one.

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[Len]

Right part of the country, hmm? *looks outside and sees nothing but trees* nope. Lol

I live about 2.5 hours drive from the nearest one.

Well, you can let UPS do the driving.

[klunkerbus]

I've purchased my DeoxIT D5 at Guitar Center.  I think they had a couple of different products from the DeoxIT line.  The distributor info tab on the CAIG corporate site might help with finding other retailers that carry it.  http://store.caig.com/

[timb]

Amazon.com carries it, often with free Prime shipping! That's where I buy mine. 91% Isopropanol is available at your local drug store/pharmacy. I buy mine by the case at Sam's Club or Costco.

Glass bottles with eye dropper caps are available online, probably Amazon. The place I used to buy eJuice (the stuff you "vape" in an electronic cigarette) from sells their juice in those bottles, so I always cleaned them out and saved them. I've got 30, 15, and 5ml sizes. They've come in handy now and then!

I'll pull together some Amazon.com links for the various types of DeoxIT later tonight. I've been meaning to write a guide explaining the various options they sell.

[MrSlack]

DeoxIT is rather expensive. About £15+ a can here.

I bought a big can of IPA for £5: http://uk.rs-online.com/web/p/precision-cleaners-degreasers/0567890/

Cut 85 gsm Xerox paper it into strips. Wet them with the IPA. One slide through the contacts and discard. Doesn't leave any lint - I looked with a USB microscope.

IPA + toothbrush/artists paintbrush is great for getting rid of flux as well.

[guy48065]

Contact spray is an acid that will eat away the oxidation, and eventually the contact itself....

That's news to me.  Some contain acetone.  I avoid those as they can dissolve/fuse plastics inside switches & pots.  Maybe that's what you meant?

I've used Tech Spray "Lube-a-trol" for decades but it's hard to find so now I recommend the expensive DeoxIT line. 

[madires]

I'm using tuner spray for that. It cleans, lubes and protects the contacts. Works also for pots. It's not as aggressive as pure contact cleaner. IPA helps only to remove grease, gunk and such stuff.

[SaabFAN]

Kontakt has a spray-oil that goes together with the cleaning agent.
The oil is really thin and runs everywhere until the solvent dries our, which happens in about 1 to 2 minutes. Then it leaves a thin coating of oil on the contacts and protects them from corrosion.
I have cleaned several CPU-Sockets, basically all my audio-connectors and my old Sega with these 2 chemicals and haven't seen a spot of corrosion on the connectors since.

[Fortran]

+1 on Tuner spray. (Teslanol T6,  Kontakt und Tuner-Spray)
Works great and I haven't needed to respray any pots yet.
Can't say if it's "the best" out there or not, but I've never needed to look for anything better.

[ez24]

I'll pull together some Amazon.com links for the various types of DeoxIT later tonight. I've been meaning to write a guide explaining the various options they sell.

To get really confused go to DeoxIT website.  I even emailed them a question on this and got a confusing answer.  Just too many products.

[Tim T]

I had had acceptable results cleaning switches of vintage test equipment using CRC mass air flow sensor cleaner obtained from a local automobile part supply store. It contains N-hexane and a proprietary compound called COzol 204,  and claims to be safe for plastic and "most sensors and connectors". Just be aware that like alcohol it is highly flammable and should not be used on energized circuits.

tim t

[SeanB]

For grease I use a synthetic food grade grease, seeing as I had to buy a 20kg drum for work. Works well, only mildly reactive with copper ( will turn it light green after a year, so do not apply to contacts, but fine on switch bushes and open ball bearings) and the oil base is perfect for lubricating fan bearings using a syringe.

The other silicone oil I use is from Tektronix, as the Phaser transfer kit has a 2l plastic bag of drum oil in it, and the used tray ( even after resetting the counter a half dozen times, those maintenance trays were expensive) still has a litre or more of oil in it. Just transfer to a syringe and use as lubrication on metal. Guaranteed not to attack aluminium, copper or other metals, though no warranty on plastics other than nylon, HDPE and strangely PVC, as that is what the bag is made from. Still have 2 used trays ( one still in the scrapped printer) for use.

[HighVoltage]

Alcohol to clean dirt off and then contact cleaner.

I have been using this "super contact cleaner, with poly phenyl ether"  for many years and it works extremely well.
My personal experience with this stuff is just fantastic.

Just today I fixed a broken DATEL Calibrator with it:
https://www.eevblog.com/forum/repair/datel-voltage-calibrator-dvc-8500-repair/

[klaus11]

Where to buy in Europe the super contact cleaner

[helius]

I have been using this "super contact cleaner, with poly phenyl ether"  for many years and it works extremely well.
My personal experience with this stuff is just fantastic.

I mainly use it as a protectant. I found some papers that said that PPE prevents fretting and intermetallic corrosion, so I put it on edge connectors. My only complaint is that the can sprays out great gobs of the stuff when I only want a drop...

[HighVoltage]

Where to buy in Europe the super contact cleaner

I buy it from Mouser.com
Free shipping over a certain invoice value and Fedex from the US delivers faster to Germany than some German companies inside of Germany.

 

[HighVoltage]

My only complaint is that the can sprays out great gobs of the stuff when I only want a drop...

Yes, the original spray head is horrible although it is suppose to be adjustable by turning.
I am using a different spray head from a completely different can and it controls it much better.

[nctnico]

So I have a few old analogue oscilloscopes that need some maintenance and repair. After looking around online on what people use to clean pots and switches, I have found many answers.

Rule number one: once a switch or pot is worn it must be replaced. Switches and potmeters have a layer of material which makes the contact. Once that layer is gone it is broken. You can try to use oil to slow down the corrosion process of the layer but in the end you can't avoid the inevitable.
Using contact spray only makes things worse because the acid component will attack anything made of metal and eat away the good parts of a piece of equipment as well. If a piece of equipment smells of contact spray I don't touch it. I have learned that lesson the hard way!

[HighVoltage]

Well, without the contact spray, I would not have been able to repair my DATEL calibrator, since those switches can not be taken apart nor replaced. And they are working absolute perfectly right now. Just make sure your contact spray is NOT conductive at all.

[helius]

some strange fascination with acids ITT...
the active ingredient in Deoxit D100 is oleic acid, which prevents corrosion.

[Shock]

Just to clarify the DeoxIT D5 is 5% of their DeoxIT ingredient which contains some lubricant, 75% mineral spirits (naphtha) and 20% propellant, but great idea make your own.

[Shock]

Rule number one: once a switch or pot is worn it must be replaced. Switches and potmeters have a layer of material which makes the contact. Once that layer is gone it is broken. You can try to use oil to slow down the corrosion process of the layer but in the end you can't avoid the inevitable.
Using contact spray only makes things worse because the acid component will attack anything made of metal and eat away the good parts of a piece of equipment as well. If a piece of equipment smells of contact spray I don't touch it. I have learned that lesson the hard way!

Obviously if the part is worn beyond servicing it's not going to help but often it's contaminated and a good flush and slight lubrication (correctly based on the type of device) will restore them back to full operation. You can do an autopsy anyway and see what the problem is for your own eyes. Carbon wear/damage or plating worn off is a different story.

[nctnico]

some strange fascination with acids ITT...
the active ingredient in Deoxit D100 is oleic acid, which prevents corrosion.

Yeah right... most acids don't go well with metals and oleic acid isn't an exception. Look at this table: http://www.engineeringtoolbox.com/metal-corrosion-resistance-d_491.html Steel and bronze are affected by oleic acid.

[helius]

That's interesting, but I'm not sure that it is relevant. Contacts are most often nickel or gold plated copper. I haven't yet seen a switch body made of gray cast iron, but who knows.

[nanofrog]

Although it looks like a hold-out from 1993, the Contact Cleaners, Protectors & Enhancers for Electronics page might be of use. 

For those in Europe, see if you can get Cramolin Contact Cleaner as it's the original Deoxit red (made in Germany).  It's really good stuff. Not sure of other sources (came up empty at RS & Farnell), but Conrad Electronics carries it (400ml aerosol can).

[Raj]

wd40 is made for metal, go ahead and use it.its just kerosene oil with some other stuff inside it

[The_Penguin]

I've been using Nu-Trol since Moby Dick was a minnow.   http://www.mgchemicals.com/products/cleaners/contact-cleaners/nu-trol-control-cleaner-401b/

[David Hess]

I also use MG Chemicals Super Contact Cleaner which has naphtha and PPE but MG Chemicals has a silicon oil based version as well.  I squirted some into a small oiler so I can apply it drop by drop instead of spraying it.  The technical data on the Craig products is too obfuscated to trust.

Potentiometers and switches which use a wiping action need to be lubricated after being cleaned.  The choices for this are polyphenylether oil, silicon oil, or grease.  Silicon oil tends to creep and interferes with soldering.  Plastic safe cleaners are usually naphtha.

I have had better results using PPE instead of grease as lubricant in potentiometers.  High quality potentiometers which have a carbon wiper may need to be disassembled to clean grease caked with carbon from the worn wiper out.

[ez24]

The technical data on the Craig products is too obfuscated to trust.

I emailed some questions to them and their answers were like their website 

I think the question was what one product should I use on the switches of an old Tek scope and they answered with half a dozen picks.

[David Hess]

The technical data on the Craig products is too obfuscated to trust.

I emailed some questions to them and their answers were like their website 

I think the question was what one product should I use on the switches of an old Tek scope and they answered with half a dozen picks.

I had the same problem trying to find which Craig products are suitable for switches and potentiometers.  They have too little information published for too many products which are all described in marketing terms.

I think CRC has a combination cleaner and lubricant but I always have trouble finding it through their documentation.

[Tomorokoshi]

3M Novec contact cleaner worked very well for a couple things recently:

http://www.3m.com/3M/en_US/company-us/all-3m-products/?N=5002385+8711017&Ntt=novec+cleaner&LC=en_US&co=cc&gsaAction=scBR&rt=rs&type=cc

I have "Novec Contact Cleaner Plus" and "Novec Contact Cleaner/Lubricant". I did not use the lubricant version yet. It uses silicone.

I used it to clean up the rotary switch on an old radio, and the rotary switch on an old voltmeter. In both cases I was trying to track down other things. If there is an intermittent problem this may be just the thing.

http://www.digikey.com/product-search/en?keywords=novec