Cleaning Plated Electrical Contacts?
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From: GregS on 21 Sep 2009 11:56 In article <VqKdnWBSC88LBirXnZ2dnUVZ_jCdnZ2d(a)earthlink.com>, "Michael A. Terrell" <mike.terrell(a)earthlink.net> wrote: > >GregS wrote: >> >> In article > <f46025b5-ecf1-4d8c-b925-6dcb0bd5ca86(a)q14g2000vbi.googlegroups.com>, Dubtron > <swohlfarth(a)gmail.com> wrote: >> >On Sep 18, 10:28=A0am, GeneO <geno...(a)yahoo.com> wrote: >> >> Have been Googling the proper way to clean plated electrical contacts >> >> but either get nothing if use " or a lot of nonrelevant hits without. >> >> >> >> Am interested in any suggestions esp how to remove the nonconductive >> >> oxides. >> >> >> >> If a connector is too damaged would also be interested in what are >> >> considered the best type replacement. >> >> >> >> Thanks >> >> >> >> Gene >> > >> >I have had very good luck repairing low current relay contacts and >> >mechanical rotary switches using "tarn-x" silver cleaner containing >> >acidified thiourea. MSDS: http://www.jelmar.com/msds/TX_MSDS_eng.pdf. >> >If you take the relay or switch apart to get to the contacts, use a >> >cotton swab with a small amount of cleaner and apply to the oxidized >> >(tarnished) surfaces. They shine right up and the surface does not >> >appear to be damaged by it. Then dry and apply a very light film of >> >silicone based contact cleaner to keep the air away and help with >> >lubrication. Works great for speaker relays in amplifiers and mode >> >switches for VCR's. >> > >> >> Silicone based products are really not a good thing, at least thats what >> some say. However sometimes a silicone grease is used to >> protect connections. Silicone sprays were common 30 years ago. >> I don't recall any of the more common recommended sprays having >> silicone. I see mixed recommendations of lubing relays. >> Some say no, but I do. > > > Silicone based chemicals were banned from all telephone switching >centers with mechanical switching. > > The old General Cement "Tuner Lube" is petroleum based and doesn't >build up an insulating film like Silicone based products. I got some of that stuff. For rubber and some plastics petroleum based products can hurt. I have been using plastic safe liquid CRC 2-26 but I really don't know whats in it. For those outside the US, if you use Cramolin Contaclean, it must be removed after cleaning because it will gum. Here is an old can. Check out the buildup at the top. http://zekfrivolous.com/misc/cramolin%20contaclean.JPG greg
From: JB on 21 Sep 2009 11:56 > Silicone based products are really not a good thing, at least thats what > some say. However sometimes a silicone grease is used to > protect connections. Silicone sprays were common 30 years ago. > I don't recall any of the more common recommended sprays having > silicone. I see mixed recommendations of lubing relays. > Some say no, but I do. > > greg Silicone based cleaners leave a residue that protects against friction but tends to insulate. You have to break through the film in order to even have contact. I have found them useful for connectors that see lots of use, such as Notebooks, but I usually have to wash them with Isopropyl to remove most of what I put on. There is no point in lubing relays. Any residue will increase the likelihood of burning of the contacts. They should be cleaned and burnished with a non-residue cleaner and as minimally abrasive tool as possible. Bond paper strips will often suffice. Isopropyl Alcohol at 90% or better is clean, leaves no residue, won't harm most plastics and is the only recommended cleaner for many switches and contacts. Do not use less than 90% as there will be risk of moisture damage.
From: GregS on 21 Sep 2009 12:45 In article <HmNtm.3127$tl3.2818(a)nwrddc01.gnilink.net>, "JB" <nospam(a)goofball.net> wrote: >> Silicone based products are really not a good thing, at least thats what >> some say. However sometimes a silicone grease is used to >> protect connections. Silicone sprays were common 30 years ago. >> I don't recall any of the more common recommended sprays having >> silicone. I see mixed recommendations of lubing relays. >> Some say no, but I do. >> >> greg > >Silicone based cleaners leave a residue that protects against friction but >tends to insulate. You have to break through the film in order to even have >contact. I have found them useful for connectors that see lots of use, such >as Notebooks, but I usually have to wash them with Isopropyl to remove most >of what I put on. > >There is no point in lubing relays. Any residue will increase the >likelihood of burning of the contacts. They should be cleaned and burnished >with a non-residue cleaner and as minimally abrasive tool as possible. Bond >paper strips will often suffice. > >Isopropyl Alcohol at 90% or better is clean, leaves no residue, won't harm >most plastics and is the only recommended cleaner for many switches and >contacts. Do not use less than 90% as there will be risk of moisture >damage. I kind of like using 70% rubbing alcohol sometimes, with its small amount of mineral oil. Any % alcohol can cause moisture problems, even 100%. The trick is to warm dry it. My knowledge of silicon is it forms waterglass in some cases and insulates. This is a powder like material. Sodium silicate. It does wash off. I also discovered thick sticky residue on my can of CRC 2-26, but its a more passive lube than the acedic nature of Cramolin Contaclean. My can of TAL-5 is also sticky, was made by WD-40 company. From memory I have never seen this happen with WD-40. greg
From: Dave Plowman (News) on 21 Sep 2009 14:05 In article <3cmdb51o9cfgaantdo289j3dlqsbpvquj4(a)4ax.com>, Ross Herbert <rherber1(a)bigpond.net.au> wrote: > I don't think I have ever come across a "plated" electrical contact. In > my experience electrical contacts are always a solid material such as > brass (cheap and nasty - often used in electrical appliances) or a more > exotic alloy material such as nickel-silver. The vast majority of connectors which aren't plain brass are plated. -- *When cheese gets it's picture taken, what does it say? Dave Plowman dave(a)davenoise.co.uk London SW To e-mail, change noise into sound.
From: Jim Yanik on 21 Sep 2009 14:45
zekfrivo(a)zekfrivolous.com (GregS) wrote in news:h987mf$4bh$1(a)usenet01.srv.cis.pitt.edu: > In article <VqKdnWBSC88LBirXnZ2dnUVZ_jCdnZ2d(a)earthlink.com>, "Michael > A. Terrell" <mike.terrell(a)earthlink.net> wrote: >> >>GregS wrote: >>> >>> In article >> <f46025b5-ecf1-4d8c-b925-6dcb0bd5ca86(a)q14g2000vbi.googlegroups.com>, >> Dubtron <swohlfarth(a)gmail.com> wrote: >>> >On Sep 18, 10:28=A0am, GeneO <geno...(a)yahoo.com> wrote: >>> >> Have been Googling the proper way to clean plated electrical >>> >> contacts but either get nothing if use " or a lot of nonrelevant >>> >> hits without. >>> >> >>> >> Am interested in any suggestions esp how to remove the >>> >> nonconductive oxides. >>> >> >>> >> If a connector is too damaged would also be interested in what >>> >> are considered the best type replacement. >>> >> >>> >> Thanks >>> >> >>> >> Gene >>> > >>> >I have had very good luck repairing low current relay contacts and >>> >mechanical rotary switches using "tarn-x" silver cleaner containing >>> >acidified thiourea. MSDS: >>> >http://www.jelmar.com/msds/TX_MSDS_eng.pdf. If you take the relay >>> >or switch apart to get to the contacts, use a cotton swab with a >>> >small amount of cleaner and apply to the oxidized (tarnished) >>> >surfaces. They shine right up and the surface does not appear to be >>> >damaged by it. Then dry and apply a very light film of silicone >>> >based contact cleaner to keep the air away and help with >>> >lubrication. Works great for speaker relays in amplifiers and mode >>> >switches for VCR's. >>> > >>> >>> Silicone based products are really not a good thing, at least thats >>> what some say. However sometimes a silicone grease is used to >>> protect connections. Silicone sprays were common 30 years ago. >>> I don't recall any of the more common recommended sprays having >>> silicone. I see mixed recommendations of lubing relays. >>> Some say no, but I do. >> >> >> Silicone based chemicals were banned from all telephone switching >>centers with mechanical switching. >> >> The old General Cement "Tuner Lube" is petroleum based and doesn't >>build up an insulating film like Silicone based products. contact wiping pressure should handle that "insulating" film. Only TEK "HF switch contacts" didn't have enough wiping pressure to deal with films left from tuner cleaner/lube sprays. > > I got some of that stuff. For rubber and some plastics > petroleum based products can hurt. I have been using plastic safe > liquid CRC 2-26 but I really don't know whats in it. For those outside > the US, if you use Cramolin Contaclean, it must be removed after > cleaning because it will gum. Here is an old > can. Check out the buildup at the top. > > http://zekfrivolous.com/misc/cramolin%20contaclean.JPG > > greg > I used to use Tarn-X on TEK 500 series tube scope rotary switches,to clean off the black oxidation. It worked great,had to wash and oven-dry the scopes anyways. You must RINSE the contacts after using Tarn-X on them. -- Jim Yanik jyanik at kua.net |