Any tips on how to quickly deoxidize parts? - Page 1
Forum section: electronics / projects

author: alank2
author_rank: Super Contributor
timestamp: July 03, 2015, 10:54:09 pm
content: I've noticed that some of the parts I am using have oxidized pretty heavily. Mostly these are through hole parts and trying to solder them leads to the solder pooling around the pin, but not really adhering to it the way it should. Is there any quick tips on how to deoxidize parts with pins like this? Do you need an acid or something?

author: mazurov
author_rank: Frequent Contributor
timestamp: July 03, 2015, 11:22:13 pm
content: Pencil eraser will work in a pinch. Caig DeOxIt products are awesome, too, but not as common as pencil erasers.

author: nanofrog
author_rank: Super Contributor
timestamp: July 03, 2015, 11:44:10 pm
content: Mechanical means will suffice.Things like ink pen erasers (slightly abrasive), or fine emery paper or sticks (kind used for fingernails) will work. My personal favorite though, is a fiberglass scratch brush (lots of uses, such as cleaning components/pads, switch contacts, rust/crud off of tools, and battery contacts for example).Also, you might also want to consider a more active flux (i.e. RA if you're not already using it on heavily oxidized components & boards).As per Caig DeOxit, I wouldn't use that (amazing performance, but it's too expensive for this). A thin layer remains on the metal surfaces that could cause problems with soldering.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: July 04, 2015, 02:02:09 am
content: Place object in chamber of elemental lithium gas at 1000 K.Hey, you said "quickly", nothing about practical...(Actually now I'm kind of curious if that would work. Beware the smoky, acrid fumes and red flames when you take it out of the oven, though.)Tim

author: SeanB
author_rank: Super Contributor
timestamp: July 04, 2015, 04:41:13 am
content: Pencil eraser works well, best is to take it and use a sharp blade ( not going to be sharp after though) and cut a slit in it to clean the whole lead at once, and to do IC leads in one pass.Another is to take a small strip of 800-1200 grit wet and dry paper and use contact adhesive to stick it to a pair of tongue depressors ( or ice lolly sticks) which you then place on either side of the lead and pull it out once.I used a small circle of 400 grit paper on the end of a pencil to clean recessed brass battery contacts, as they would frequently come with an oxide coating from new that prevented good contact.

author: helius
author_rank: Super Contributor
timestamp: July 04, 2015, 04:51:20 am
content: it's been suggested to use aspirin as a more effective reducing agent. I guess you can just smear it on the oxidized pins and apply heat. Like water-soluble flux, it needs to be washed off.

author: dadler
author_rank: Unknown
timestamp: July 04, 2015, 04:51:39 am
content: I've used a small stainless wire brush with good success.

author: Warhawk
author_rank: Frequent Contributor
timestamp: July 04, 2015, 06:30:28 am
content: Quote from: helius on July 04, 2015, 04:51:20 amI use Aspirin for a magnet wire isolation removal. Be careful, the generated gases are very toxic.

author: obiwanjacobi
author_rank: Super Contributor
timestamp: July 04, 2015, 08:00:51 am
content: WD-40

author: Ian.M
author_rank: Super Contributor
timestamp: July 04, 2015, 08:21:42 am
content: Pinch in a folded green pan scourer, pull the lead through.

author: GreyWoolfe
author_rank: Unknown
timestamp: July 04, 2015, 01:11:38 pm
content: I use a fine grit sanding pad with handle from the big box home improvement store. I place the lead on the workbench at the edge and lightly scrub with the pad as I rotate the component.

author: jimon
author_rank: Regular Contributor
timestamp: July 04, 2015, 01:43:34 pm
content: If it's only about leads, why not just retin them with tons of flux ? Works just fine is most cases.

author: Pjotr
author_rank: Frequent Contributor
timestamp: July 04, 2015, 02:27:27 pm
content: Simply use those wall mart abrasive plastic kitchen sponges! 25 for $1Or when you have to spend money those 3M Scotch-Brite pads.

author: ConKbot
author_rank: Super Contributor
timestamp: July 04, 2015, 03:56:09 pm
content: RA type rosin flux (full octane fully activated, not just the mildly activated stuff, gotta make sure you clean it fully) and a solder pot with 63/37 in it. Just get a to for removing the dross as it'll build up quickly as the junk comes of the leads. After the parts cool briefly, into a beaker of ipa to soak.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: July 04, 2015, 04:01:16 pm
content: Quote from: Warhawk on July 04, 2015, 06:30:28 amFYI, aspirin is an organic acid like regular rosin, so this should be a fine method. It may break down into acetic acid and salicylic acids on heating, for even more stripping power. And yes, beware the fumes; snorting vaporized aspirin is probably not a desirable method of dosing!Tim

author: oldway
author_rank: Super Contributor
timestamp: July 04, 2015, 05:46:42 pm
content: For large copper cables, I use nitric acidRinse well afterwards.Be careful, use gloves and protective glasses, this acid is highly corrosive.

author: rdl
author_rank: Super Contributor
timestamp: July 04, 2015, 07:27:44 pm
content: If they're jelly bean parts, just throw them away and buy new. Life is too short.If you're in a hurry though, any of the various kinds of abrasion already mentioned here should work.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: July 04, 2015, 11:13:39 pm
content: Quote from: oldway on July 04, 2015, 05:46:42 pmYikes, a little too well I would think!HCl also dissolves copper oxides nicely, but the problem with acids (especially mineral acids) is, they stick in pores in the metal, and never really rinse away. So you can wash with HCl, then rinse several times with neutral water and mild base, and get a clean surface ... that some months later, still inevitably turns green (not just deeper copper, then brown).It's a good combination when the pores are about to be permanently covered, like for tinning, galvanizing, electroplating, etc. For this reason, try to cover the entire surface, even if you don't need to.I've also had material that's so porous on the surface (after the acid) and doesn't tin well. If it's covered in rust or scale, you're probably best off with a mechanical solution for this reason.Tim

author: GreyWoolfe
author_rank: Unknown
timestamp: July 05, 2015, 02:47:26 pm
content: Quote from: rdl on July 04, 2015, 07:27:44 pmLife is too short to waste gas and money running to Rat Shack or wait for the parts to come in the mail. Why buy them if I have them.A few seconds with an abrasive pad and Bob's your Uncle.

author: rdl
author_rank: Super Contributor
timestamp: July 05, 2015, 03:34:05 pm
content: Well, other than it costing you no gas to have something delivered and that the Shack probably wouldn't have what you needed even if they were still open, isn't that basically what I said?Quote

author: jdraughn
author_rank: Regular Contributor
timestamp: July 07, 2015, 01:52:08 pm
content: Would battery terminal cleaner from the local auto parts store work?

author: alank2
author_rank: Super Contributor
timestamp: July 09, 2015, 02:25:38 pm
content: So yesterday I tried using a small metal file on the leads. I hit all 4 sized of each lead. Did not help much at all. Still the solder wanted to pool around the pin and not adhere to it.I'll try some flux pen on them next time and see how that goes...

author: ctesla75
author_rank: Contributor
timestamp: July 09, 2015, 02:50:23 pm
content: i usually use a sharp blade to scrape away oxidation or fine sandpaper ,element14 sell an eraser that i have used at work on pcbs that came preoxidised from chinese pcb house. part number 141330 from kelan it worked pretty well. some guys at work have used hydrochloric acid, i dont like it but do use it on oxidised cables ocassionaly that need to be fixed .

author: T3sl4co1l
author_rank: Super Contributor
timestamp: July 09, 2015, 10:14:04 pm
content: Your solder is flux core, right?Are the leads nickel or stainless by any chance?Is your ambient air rich with an unusual concentration of fluorine by any chance? (Joking of course; but if there were something in the air that rapidly made normally solderable metals unsolderable, I can't think of what else would.)Tim

author: alank2
author_rank: Super Contributor
timestamp: July 09, 2015, 10:19:46 pm
content: I'm using a water soluble flux solder.This is the part:http://media.digikey.com/pdf/Data%20Sheets/C&K/PVA%20Keyswitch.pdf

author: T3sl4co1l
author_rank: Super Contributor
timestamp: July 10, 2015, 01:12:35 am
content: No mention of lead finish / plating, but they say solderable.Tim

author: calexanian
author_rank: Super Contributor
timestamp: July 10, 2015, 03:27:41 am
content: put parts in a hydrogen redox furnace at 1000 C.. everything else will be reduced away in seconds but the melted metal remains at the bottom of the furnace will be oxide free!Otherwise you could just brush on some RA type flux when you solder. Works great. Just clean it really well when done.

author: Stonent
author_rank: Super Contributor
timestamp: July 10, 2015, 04:39:50 am
content: Quote from: alank2 on July 09, 2015, 02:25:38 pmPlease choose from one of the following:I am soldering with:[ ] 60/40 Solder[ ] 63/37 Solder[ ] Something from the plumbing department[ ] That RoHS garbage(Yes, I'm racist against RoHS solder. It doesn't stick well, it looks ugly, it has horrible plasticity under thermal fluctuations, forms cold solder joints and it eats the plating off your soldering iron until you're shoveling solder around with a broken copper nail.)

author: alank2
author_rank: Super Contributor
timestamp: July 10, 2015, 12:01:13 pm
content: Kester 60/40#66/33124-6040-6403

author: Stonent
author_rank: Super Contributor
timestamp: July 10, 2015, 03:33:00 pm
content: Quote from: alank2 on July 10, 2015, 12:01:13 pmWell darn I thought I had the easy answer and you drop that bomb. Kester or Multicore can't do much better than those.

author: alank2
author_rank: Super Contributor
timestamp: July 10, 2015, 03:41:02 pm
content: I've had this problem with one other part, a female header, it has a goldish looking finish on it.

author: nanofrog
author_rank: Super Contributor
timestamp: July 10, 2015, 06:42:58 pm
content: Quote from: alank2 on July 10, 2015, 12:01:13 pmAlthough Kester is a quality manufacturer and the alloy is suitable, that particular flux type is horrible for highly oxidized parts and boards (it's also corrosive, so must be cleaned off).Kester 44 would yield far better results, as it's made for repairs where you're likely to encounter heavily oxidized stuff (uses RA flux; same as 1544 liquid flux).

author: alank2
author_rank: Super Contributor
timestamp: July 10, 2015, 07:30:21 pm
content: I use it because it can be cleaned off with a water rinse. I don't want to use something that is a pain to get off the board. With that said, I don't mind putting the switches through some sort of process ahead of time to deoxidize them if that is what it takes.I've got some radio shack 60/40 rosin that works a little better, but again, I want something that is easy to clean.

author: helius
author_rank: Super Contributor
timestamp: July 10, 2015, 07:51:29 pm
content: I may be mistaken, but my understanding was that water-soluble fluxes like 331 could be used for soldering to passivated metals like steel or aluminum. They need to be cleaned off immediately in hot water.RA fluxes like 44, are normally used for hand soldering. There is no particular need to clean off the residues at all, since they are non-corrosive. If cleaning is desired they come off with IPA or commercial flux removers, which are usually handier to keep at the bench than a hot water supply!

author: alank2
author_rank: Super Contributor
timestamp: July 10, 2015, 08:04:44 pm
content: I don't like the sticky mess on pcb's that rosin makes. I wonder if I cleaned the pins with a flux before soldering them on the board and just used my regular kester if that would work.

author: JacquesBBB
author_rank: Frequent Contributor
timestamp: July 11, 2015, 06:24:08 am
content: I use the same steel pad that is used in the kitchen for cleaning the pans.as herehttp://www.amazon.com/Scotch-Brite-Stainless-Steel-Scouring-3-Pad/dp/B002CQTXBC/ref=sr_1_1?ie=UTF8&qid=1451978984&sr=8-1&keywords=Scrub+pad+steelI put the amazon ad for illustration, but just buy it at the local grocery store.It is similar to the brass pad used for cleaning the soldering iron, but in steel, much cheaper and more effective.I systematically clean with it the leads of old parts. It is very quick Just wipe the lead once or twice with the pad, and its done.Much quicker than anything else.

author: Deathwish
author_rank: Unknown
timestamp: July 11, 2015, 07:23:02 am
content: stick them all in caustic soda overnight, whats left will be good to go

author: TerraHertz
author_rank: Super Contributor
timestamp: July 12, 2015, 02:56:05 am
content: Quote from: T3sl4co1l on July 04, 2015, 02:02:09 amI was thinking a bath of liquid Sodium would work pretty quickly too.Personally, for oxidized component leads I use a stainless steel scourer pad, of the dishwashing kind.Squeeze pad around component leg, pull leg through pad. Takes the oxide layer off fast. And then the tin plating off the copper or steel leg, if you overdo it.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: July 12, 2015, 06:50:09 am
content: Quote from: TerraHertz on July 12, 2015, 02:56:05 amMy first thought was hydrogen (also suggested above), but that would be slow.Sodium liquid might not get into all the crevices, so it's probably not the greatest. For reaction rate, you'll want it hot anyway; if you're simply simmering it under sodium, the vapor pressure alone might do it, but you might as well vaporize it wholesale.Yum, a kettle to "steam" parts in, featuring 800C alkali metal gas!So that's probably not too bad.Going further requires some quirks of chemistry: there are actually quite a lot of compounds that are stable in the presence of sodium. The general idea is: if it has more binding energy, it won't go (and the opposite reaction will proceed vigorously). A perfect example is aluminum or magnesium and Na2O thermite (has to be done in a sealed "bomb" to obtain solid metal on cooling, otherwise the metal vapor blows itself away).I suspect lithium is just that little bit more reactive; it tends to stick to a lot of things, so might have better conversion of Fe2O3 and etc.Alkali oxides also melt and vaporize pretty easily (low binding energy -- part of the problem), so the oxides should clear away pretty well. (You wouldn't want to do this with, say, calcium vapor -- CaO basically doesn't melt...)But it's still a tricky problem; even with heat, you're mostly doing the reaction at the surface, so that you might get a metallic crust over a lumpy rust deposit, over porous metal. Reversing that can be done with hydrogen (slow, gets into the crevices better) or electrolytically (*very* slowly), but yeah, you're talking sheer diffusion time at this point. And it's still not perfect, because you're ultimately left with porous metal in place.So proper "deoxidizing" can be a very tricky, poorly defined and difficult problem, indeed!Hence why -- if removal can be allowed -- it's generally the preferable solution!(This has been your daily dose of chemistry.)Tim

author: alank2
author_rank: Super Contributor
timestamp: July 28, 2015, 11:22:12 pm
content: More on these switches. I tried to use rosin flux leaded solder on them and the terminal turns black as soon as the heat hits it. Some of them are rough after I solder them too almost like the heat does something internally. Any more ideas?I have 1800 of these...so it would be worthwhile to come up with a technique to clean them before soldering them. I could disassemble them and put them through an ultrasonic cleaner followed by a bake at 110 to dry them out... Any thoughts on the least work for an acceptable use plan?

author: alank2
author_rank: Super Contributor
timestamp: July 29, 2015, 01:41:14 am
content: Here is a picture:The left two contacts are cleaner than the right two. You can see some black on the 3rd one from the left on the middle contact.Also note the corrosion on the backside of the right most one.I tried just applying heat to a post (no solder) and sure enough it turns black (and smells bad).Are these all silver plated?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: July 29, 2015, 02:23:31 am
content: Sounds likely. "Smells bad" describes silver sulfide, which forms spontaneously from something or other sulfurous in the air (doesn't take much, and it goes very slowly). Hence, tarnish. Which doesn't really flux, as you've noted.Brush it off and keep on going. A soft wire brush should do.Tim

author: Ian.M
author_rank: Super Contributor
timestamp: July 29, 2015, 12:31:27 pm
content: Try Goddards silver dip on the pins ONLY. If you need to dismantle the switches its just not worth it.

author: alank2
author_rank: Super Contributor
timestamp: July 29, 2015, 03:51:51 pm
content: Thanks Ian, I'll try the dip on the pins only and see how it does.I separated the switches by seeing if I could tap them very lightly to detect if they move/bounce slightly. About half of them moved easily and the other half don't so probably half have internal corrosion...

author: technix
author_rank: Super Contributor
timestamp: July 29, 2015, 05:10:37 pm
content: I usually just scrape it with my pliers/side cutters/utility knife/sandpaper/whatever that is handy and abrasive enough to do the job, and it will usually do the trick. Pliers can also straight out the leads for old part stocks (which I happen to have a lot.)For those that is most difficult to remove, I tend to do a forced tinning that removes the oxide both physically and chemically and tin the lead immediately: Dipping the lead into melted rosin flux applying my high power soldering iron, and scrape the oxide with the tip of my iron loaded with solder. This forced tinning can sometimes drive fresh, molten solder below the oxide loosening it, and the all-natural rosin I used is capable of reacting with the oxide, removing it at the cost of producing lots of fumes. (essentially a small scale thermite-like reaction) By the way, my daily driver solder, which is the lead free silver containing type, does this trick pretty well.

author: alank2
author_rank: Super Contributor
timestamp: January 04, 2016, 08:54:38 pm
content: I'm still fussing around with these switches. My chemical clean method using a quick dip in silver cleaner followed by a water rinse isn't working as well as I would like.What about cleaning the contacts on them much like the soldering iron tip is cleaned with brass/copper wool? Can I just jam a switch into a pile 20 times or so to scrape off the oxidation? What about coarse steel wool?Thanks,Alan

author: AlxDroidDev
author_rank: Frequent Contributor
timestamp: January 04, 2016, 08:58:15 pm
content: Have you tried ammonia?I´ve used concentrated ammonia to remove oxidation from surfaces, and it works very well. Care must be taken to work in a well ventilated area, and using a mask.

author: KL27x
author_rank: Super Contributor
timestamp: January 04, 2016, 09:18:55 pm
content: QuoteNitric should be much better than HCl. The chloride in HCl is the main problem. Halides are super corrosive. But the effect isn't particularly bad on copper or solder. Tons of people etch their boards with HCl and peroxide, leaving trace mineral embedded in the sides of the traces. (Even more hobbyist and professional boards are etched with ferric chloride, for that matter).It's a much bigger problem with ferrous metals, where the corrosion is rust... bulky, creeping, insidious, self-propagating. This is much more certain to cause connection problems. Rust mechanically forces the joint apart and promotes more rust to form in the crevice until the joint completely separates.Nitric acid would be fine for cleaning parts, IMO. Or phosphoric acid. Or citric acid. HCl would even be not so great, but still fairly ok on non-ferrous metals, with a good cleaning. I have some pcb's where I used zinc chloride plumber's flux, washed with water, after. These are many years old, now, and they look fine. Wherever I have used the same flux and wash on steel battery terminals? Corroded joints that failed after about 6 years.

author: helius
author_rank: Super Contributor
timestamp: January 05, 2016, 05:54:44 am
content: Brass brushes are sold specifically for cleaning corrosion from contacts, and fiberglass scratch brushes will do the same.I recently did an experiment of making a saturated oxalic acid solution and dipping rusty tools in it. A lot of rust loosened and disappeared after several minutes, but some rust was more tenacious and took hours to come off. A few spots never did, and it took a steel wire brush to get them clean. After the acid I rinsed in running water, then dried and used WD40 which I wiped off. Then either motor oil or T9 for protection.One thing about the oxalic acid dip is that after an hour or more, the metal gets progressively etched. More than 24 hours will cause a lot of etching. It can be smoothed out somewhat with a steel wire brush but dipping for that long is a mistake.

author: KL27x
author_rank: Super Contributor
timestamp: January 05, 2016, 06:28:14 am
content: QuoteI have a feeling this has nothing to do with oxidation. I have purchased some really old components (germanium diodes for playing around with) which never soldered. It didn't matter using flux or a scratch brush or even sanding/filing the surface. I never did figure it out and tossed them.If one were really keen to use a specific component, I suppose one could file the lead into a square or triangle and wire wrap them.If anyone knows how to solder to the little foil tabs on li ion pouch cells, curious minds what to know. I've read you can even solder to aluminum by abrading it under oil, but I've never been able to do that, either.

author: apelly
author_rank: Unknown
timestamp: January 05, 2016, 06:36:34 am
content: Flux & solder pot? Rinse and repeat?edit: At least you could tin them all in one go then.

author: alank2
author_rank: Super Contributor
timestamp: January 05, 2016, 01:08:26 pm
content: Quote from: KL27x on January 05, 2016, 06:28:14 am

author: IdahoMan
author_rank: Regular Contributor
timestamp: July 01, 2016, 07:14:23 pm
content: On the subject of deoxidizing: What about high-strand-count copper wire?It's too fine and bunched to clean it mechanically (sandpaper/rubber-eraser). Can simple rosin flux and a flame be used? Or viniger? A deoxidizing cleaner? It will not be soldered, it's for use in a crimped/clamped connection.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: July 01, 2016, 07:44:35 pm
content: Like, corroded welding cable?Or do you mean coated wire, i.e. Litz?You definitely don't want to use an acid. That only makes things worse in the long run.There needn't be a "best" way to remediate such things; if you can't tin it, and you can't clean it (because cleaning is best with acids, it's true..), and you can't crimp it [with low resistance], it really just isn't wire anymore, it's trash..Tim

author: jaxbird
author_rank: Frequent Contributor
timestamp: July 01, 2016, 07:45:51 pm
content: Use corrosive fiux, it's that simple.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: July 01, 2016, 07:48:34 pm
content: Quote from: jaxbird on July 01, 2016, 07:45:51 pmHow do you get it out of the rest of the wire?

author: jaxbird
author_rank: Frequent Contributor
timestamp: July 01, 2016, 07:54:27 pm
content: Quote from: T3sl4co1l on July 01, 2016, 07:48:34 pmAfter corrosive flux, I usually spray everything with IPA, then I've never had any issues. Using corrosive pipe flux is the cure in some situations, just watch it boil and then the solder will wick instantly.

author: IdahoMan
author_rank: Regular Contributor
timestamp: July 01, 2016, 08:33:25 pm
content: Quote from: T3sl4co1l on July 01, 2016, 07:44:35 pmYeah, welding cable. 6AWG-350MCM.How oxidized is too oxidized? I know it should be shiny pink/copper color, ideally. BTW, how far can the oxidization reach under the insulation if the wire is clean-cut on the spool? I "capped" the ends with some tape just in case.Thanks for responding.IM

author: T3sl4co1l
author_rank: Super Contributor
timestamp: July 01, 2016, 11:02:13 pm
content: May also be an option to strip it back pretty far, crimp, and fill the crimp with Sil-Phos or something like that. That uses the least amount of flux, and leaves a glassy rather than acidic residue. Then wrap everything with tape and/or heat shrink. Maybe squirt a little grease into the burned end, so the strands are a bit better lubricated? They'll be much softer (annealed), which may be a fatigue problem too.Tim

author: nanofrog
author_rank: Super Contributor
timestamp: July 02, 2016, 12:37:41 am
content: Can you post a photo of the stripped wire ends you're trying to crimp?FWIW a proper crimp will break up the oxides (mechanical) in order to form a cold weld, so you may luck up.If the corrosion is too extensive however, stripping it back will be the only option.

author: Delta
author_rank: Super Contributor
timestamp: July 02, 2016, 01:12:53 am
content: Ammonium chloride. Our friends who work with copper and fluids (rather than copper and electrons) love this stuff.

author: sarepairman2
author_rank: Frequent Contributor
timestamp: July 02, 2016, 02:22:03 am
content: I think that I am going to make some specialty tooling that will accept fine strips of very high grit sand paper with specific contours just for the purpose of PCB component restoration.Then I think robrenz is gonna make a better version of what I made.like hand tools made for the job. I bet you would need several different kinds to handle different lead types, smd parts, etc.This kind of stuff could save you a fortune in fustration

author: Smokey
author_rank: Super Contributor
timestamp: July 02, 2016, 02:28:54 am
content: Lime away!