Death on a soldering iron tip! - Page 1
Forum section: electronics / general

author: Mike01Hu
author_rank: Newbie
timestamp: July 06, 2017, 11:28:16 am
content: Today, in the Electronics Weekly news letter was an article describing a Pi conversion to an old radio. Great, I thought, until I read this:“It’s worth noting that you should take some care when desoldering the wires from the speakers, and the solder joint holding the circuitry to the metal part of the chassis, since it will be lead solder. We used a separate soldering iron tip and discarded it after use.”I must now throw out all my expensive bits after each soldering job until I've used up all my lead based solder. Doh!

author: Gyro
author_rank: Super Contributor
timestamp: July 06, 2017, 11:44:53 am
content: I suspect they are talking about leaded solder joints in a normally lead-free soldering environment. Yes, you would want to use a separate tip for that.I've absolutely no Idea why they would want to discard it though! Just keep it, clearly marked, for the next leaded soldering job.

author: Yansi
author_rank: Super Contributor
timestamp: July 06, 2017, 11:50:53 am
content: More likely an ultradumb idiot afraid of lead.

author: GreyWoolfe
author_rank: Unknown
timestamp: July 06, 2017, 12:47:50 pm
content: Quote from: Gyro on July 06, 2017, 11:44:53 amI actually keep my one lead free Metcal tip in its package when not in use. No cross contamination here.

author: rdl
author_rank: Super Contributor
timestamp: July 06, 2017, 01:00:21 pm
content: Quote from: GreyWoolfe on July 06, 2017, 12:47:50 pmSame here. I keep all my lead free soldering stuff stored separately to avoid contaminating my good leaded solder with that horrible lead free garbage.

author: Ian.M
author_rank: Super Contributor
timestamp: July 06, 2017, 01:01:17 pm
content: In spite of the impending BREXIT, critical thinking about compliance with EU directives is still vanishingly rare!While in a production or commercial repair shop environment, avoiding cross-contamination between leaded and lead free solder systems is most easily done by having separate colour coded soldering stations, preferably with mechanically incompatible tips, and also separate colour coded accessories (anything that comes into contact with the solder), in a R&D lab or hobbyist environment, to clean the lead from a lead contaminated tip that's otherwise in good condition with intact plating, its sufficient to 'wash' it three times with a generous quantity of lead free solder, wiping off as much solder as possible before, in-between and after each application, using a disposable paper wipe. Assuming 60/40 Sn/Pb solder initially on the bit, and an order of magnitude contamination reduction each time, by the third time you are down to 0.04% lead remaining from the SnPb solder. By the time its further diluted in the first lead free joint you make with the cleaned bit, it will be negligible compared to the ROHS solder permitted 0.1% upper limit for lead, even if the 'lead free' solder used is itself contaminated with a permissible concentration of lead.

author: WastelandTek
author_rank: Frequent Contributor
timestamp: July 06, 2017, 01:25:25 pm
content: they threw away that poison solder tip, but then probably blithely cleaned up the radio case with a dihydrogen monoxide solution.

author: alm
author_rank: Super Contributor
timestamp: July 06, 2017, 04:10:56 pm
content: I seem to recall that adding even a small amount of leaded solder to a lead-free solder connection can degrade the joint. Not sure what the exact minimum concentration leaded solder is that would still cause problems. So using separate tips makes perfect sense to me, even if you ignore the RoHS and just worry about quality.If the shop never deals with leaded solder (only works on modern boards), then keeping the tip may not make sense (keep a $5 tip that may result in a defect that costs much more to resolve). I imagine that your average cell phone / laptop repair shop will not have much use for leaded solder, for example.

author: ebastler
author_rank: Super Contributor
timestamp: July 06, 2017, 04:26:37 pm
content: Quote from: Mike01Hu on July 06, 2017, 11:28:16 amOff topic here, but: What is "a Pi conversion to an old radio"?

author: WastelandTek
author_rank: Frequent Contributor
timestamp: July 06, 2017, 04:29:48 pm
content: Quote from: ebastler on July 06, 2017, 04:26:37 pmUsing the cabinet, speaker, and sometimes audio section of a vintage receiver to play internet delivered audio. A hipster fad.In this case I am assuming that a raspberry pi is being used as the network connected audio player.

author: RGB255_0_0
author_rank: Frequent Contributor
timestamp: July 06, 2017, 04:32:25 pm
content: Quote from: alm on July 06, 2017, 04:10:56 pmI haven't seen _any_ repair video explicitly use lead-free. Repairs are almost exclusively done with leaded solder (at least the ones I've watched). Only Julian seems to use lead-free but his soldering videos are hard to watch.This would be different if it was a big corporate repairing equipment - possibly even US-based ones.

author: Nusa
author_rank: Super Contributor
timestamp: July 06, 2017, 06:11:30 pm
content: Realize EU ROHS directives only have an indirect effect on the USA. Manufacturers that have any interest in the global market have complied out of self-interest, and because the supply chain is mostly lead-free now, not because local law forced them to. California does have an ROHS law, but it only applies to sale and disposal of newer display devices (TV's, monitors) over 4 inchs in size. I'm not aware of any laws that restrict repair shops from using leaded solder.

author: Ian.M
author_rank: Super Contributor
timestamp: July 06, 2017, 06:22:47 pm
content: Lead free boards and parts (not including BGA) reworked with SnPb, are generally reliable with only minimal attention to avoiding mixed alloy joints.The other way round is more problematic as as little as 0.5% Pb can weaken SAC and SnCu alloy joints. However trace Pb contamination is not an issue.e.g. Kester Ultrapure K100LD Lead-free Solder Alloy (a doped SnCu eutectic), as supplied can contain up to 0.050% Pb. (half the EU ROHS limit) This is consistent with the similar levels of Lead seen in the analysis of better grades of commercial Tin.Cleaning a bit by the process I gave in post#5 *WILL*, worst case, reduce the Pb carried over from the previous 60/40 Sn/Pb alloy to a contribution of less than a tenth of the permitted maximum for the alloy in the first joint made after cleaning, as long as more than ten times the residual solder is applied to the bit at each stage, thoroughly wetting and mixing with the tinned layer on the bit.

author: stj
author_rank: Super Contributor
timestamp: July 06, 2017, 07:25:09 pm
content: the legal bit in the EU can be summed up like this.any new commercial product must be RoHS compliant. (since 1996 i think)any repairs done to RoHS compliant stuff must remain RoHS compliant - read that a few times, you guys who like to lead re-ball stuff.any repairs done to pre-RoHS or exempt equipment can use whatever you like.now the important bit.if you do construction or repair comercially - that means for other people, just for clarity.if you break RoHS by using leaded solder or old parts tinned with leaded solder to repair RoHS compliant products, the fine if you get caught is potentially HUGE.business destroying huge.the chances of getting caught are very very low - so far, but not worth risking.local "authorities" do have the abillity to spot-check, and if they decide to go on a "revenue-hunt" i wouldnt want to be the victim!!

author: Ian.M
author_rank: Super Contributor
timestamp: July 06, 2017, 07:37:39 pm
content: Quote from: stj on July 06, 2017, 07:25:09 pmIt only takes ONE disgruntled ex-employee to rat you out.

author: ebastler
author_rank: Super Contributor
timestamp: July 06, 2017, 07:57:44 pm
content: Quote from: stj on July 06, 2017, 07:25:09 pm2006 for general electronic products, I think. Much later for various specialized categories of products. For industrial monitoring and control equipment, RoHS is just about to become effective, on July 22 2017.QuoteWhere do you get this information? Fines in Germany are "up to 100.000 Euro", but they will be imposed in proportion to the damage you cause and/or the financial gain you derive from bringing non-compliant products to the market. A fine that ruins your business because you have used the wrong type of solder in repairs seems quite implausible.

author: RGB255_0_0
author_rank: Frequent Contributor
timestamp: July 06, 2017, 08:04:49 pm
content: Quote from: Ian.M on July 06, 2017, 07:37:39 pmOnly takes one employee to tell the local or national authorities about non-compliant CE equipment also. I reckon, if I went to North Somerset Council and said someone was doing non-RoHS-compliant repair (a la moi) I'd get a look like I needed sectioning.

author: stj
author_rank: Super Contributor
timestamp: July 06, 2017, 08:11:31 pm
content: Quote from: ebastler on July 06, 2017, 07:57:44 pmin the u.k. fines are based in income / ability to pay.think "bandits" pointing a gun at you and asking for your wallet!

author: stj
author_rank: Super Contributor
timestamp: July 06, 2017, 08:14:49 pm
content: Quote from: RGB255_0_0 on July 06, 2017, 08:04:49 pmdepends if they know how much money they could extract from the situation.it's always about the money.like when they send kids to buy smokes or beer in order to bankrupt the shopkeeper with fines!!(notice they never pull that shit with supermarkets, because they have lawyers who would counter-sue for entrapement!)

author: Cerebus
author_rank: Super Contributor
timestamp: July 06, 2017, 08:27:26 pm
content: Quote from: RGB255_0_0 on July 06, 2017, 08:04:49 pmFor the non-Brits here, that refers to being "detained under section 8 of the Mental Health Act 1983".'Sectioned' is one of those highly irregular English verbs, as in:I'm eccentricYou're crazyHe's been sectioned

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: July 06, 2017, 08:47:37 pm
content: Hi,There is also 'section 8' (USA Military). In the TV series M.A.S.H. the character Klinger was trying to get a section 8, a discharge based on being mentally unfit for service.Regards,Jay_Diddy_B

author: RGB255_0_0
author_rank: Frequent Contributor
timestamp: July 06, 2017, 08:49:02 pm
content: Quote from: stj on July 06, 2017, 08:11:31 pmFrom what I have found, it's £5,000 per item found in breach. It'd probably cost about as much to test the solder though.

author: stj
author_rank: Super Contributor
timestamp: July 06, 2017, 09:11:54 pm
content: it costs about £5 to test the solder - less in quantity.you buy chemical swabs that change colour if they detect lead.

author: Cerebus
author_rank: Super Contributor
timestamp: July 06, 2017, 10:02:44 pm
content: Quote from: stj on July 06, 2017, 09:11:54 pmThat's merely a 'presumptive test', you'd need a properly controlled test carried out by a suitably qualified chemist to meet the kind of evidential standard required to get a conviction in court. A presumptive test may show that there is lead present, but it doesn't show how much is present and as there is a permitted level of lead in 'lead free' solder the amount could be quite acceptable and still show 'lead present'.

author: Electro Detective
author_rank: Super Contributor
timestamp: July 06, 2017, 11:01:20 pm
content: Off TopiQ slightlyIf one stockpiles a few rolls of lead solder ASAP for the future, is there a shelf life to think about?i.e. will the internal rosin/flux go weird, inefficient, or any negatives?Do some some solder brands/manufacturers do better in regards to long term storage? thinking 'Multicore', 'Jaycar' brands etcfwiw I ran out of the 'Multicore' brand a while back and gave the Jaycar (Digitech?) brand a try,so far so good, always in stock and keeps our local geek lads in a job tooAre the lead solders made today still the same, better, worse quality than say 20 years ago?--------------------In the near future will there be lead solder bounty hunters with digi-mech hound dogs to sniff out the last of the anti-lead free rebels?That last question is optional btw

author: Nusa
author_rank: Super Contributor
timestamp: July 06, 2017, 11:14:10 pm
content: Re shelf life:http://www.kester.com/Portals/0/Documents/Knowledge%20Base/Kester%20Shelf%20Life%20Policies.pdf?ver=2016-09-13-140726-910QuoteBut they'll only warranty it for 3 years, which is bound to be a very conservative number.I've used flux-core solder that was over 15 years old without noticing any performance issues. How long do you need?

author: WastelandTek
author_rank: Frequent Contributor
timestamp: July 06, 2017, 11:18:48 pm
content: Quote from: Electro Detective on July 06, 2017, 11:01:20 pmI've pretty much given up on all other social activism and at this point I'm just lobbying for co-ed prison camps.

author: stj
author_rank: Super Contributor
timestamp: July 06, 2017, 11:54:34 pm
content: there is nothing wrong with pb-free solder as long as you choose one with the right flux in it.

author: Electro Detective
author_rank: Super Contributor
timestamp: July 06, 2017, 11:59:21 pm
content: Quote from: Nusa on July 06, 2017, 11:14:10 pmSame here, just wondering if the new stuff hasn't been chemically messed with to go 'off' in a few years,even bulk solder ain't cheap and I don't want to be tossing it out in a few years timeand still be paying off the credit card

author: VK5RC
author_rank: Unknown
timestamp: July 07, 2017, 12:12:37 am
content: An old ham was clearing out the shack and I bought (1$) a very old roll of multicore solder (still boxed - not on a reel), the surface of the solder had oxidised, the joints appeared to have oxide floating on the surface. The actual joint and flux action appears to be fine. If I cleaned the solder of the oxide, with a rag 1st, then the joints looked fine. I kept it as a heritage item - couldn't be bothered to clean my solder!

author: Cerebus
author_rank: Super Contributor
timestamp: July 07, 2017, 12:59:54 am
content: Quote from: Electro Detective on July 06, 2017, 11:01:20 pmThe aerospace guys pull the solder off the shelf 10 years after the 'manufactured on' date. Given how cautious they tend to be, that probably sets the shelf life for us mere mortals at upwards of 30 years.I'm still on the same reel of Multicore 60/40 that was bought back around 2000 and there's nothing wrong with it. One caveat, I'm a great believer in "there is no such thing as too much flux" so I tend to hit everything with the flux pen before I start, so if the flux in the cores is any less active than it was then I probably wouldn't notice too much because of my working methods.

author: Circlotron
author_rank: Super Contributor
timestamp: July 07, 2017, 01:02:37 am
content: Quote from: WastelandTek on July 06, 2017, 01:25:25 pmThen after that lit up a cigarette.

author: alm
author_rank: Super Contributor
timestamp: July 07, 2017, 01:15:22 am
content: Quote from: VK5RC on July 07, 2017, 12:12:37 amYou are supposed to cut off a fresh length of solder and clean it with an IPA wipe before every joint anyway! Did you not watch the expert-level soldering tutorials?

author: Electro Detective
author_rank: Super Contributor
timestamp: July 07, 2017, 01:40:25 am
content: Thanks guysI'm going to buy up some rolls of the good stuff for a rainy day, store it well and take my chances it will be fine in 20 yearswhen I need to get stuff fixed asap, not surfing the web for 'old school' over priced 'vintage' solderor suss crap Made In?? that crumbles, doesn't take.. or catches fire beyond 30 voltsbtw Where is the decent quality lead solder made nowadays? or has that gone over to Well Hung Lo land as well?

author: vk6zgo
author_rank: Super Contributor
timestamp: July 07, 2017, 02:09:01 am
content: Quote from: VK5RC on July 07, 2017, 12:12:37 amBoth "high reliability hand soldering" courses I did recommended cleaning the solder before use, so I do it without thinking about it!

author: stj
author_rank: Super Contributor
timestamp: July 07, 2017, 10:03:15 am
content: before you go buying all the lead solder you can find,a question - do you know which flux is good?it's no different to the lead free solding in that respect, there are good fluxes and bad ones.having not used it for over a decade i cant remember what i used other than it smelling like flowers!

author: Cerebus
author_rank: Super Contributor
timestamp: July 07, 2017, 10:21:20 am
content: Quote from: stj on July 07, 2017, 10:03:15 amCan't remember? That'll be the effect of all that lead then...

author: Cyberdragon
author_rank: Super Contributor
timestamp: July 07, 2017, 05:26:25 pm
content: I tried using the original solder reel I found in my old Tek one day and all it did was let out clouds of smoke and wouldn't stick! I examined a tiny piece of it and it seems the flux has gone all brown and nasty inside!So no, don't use old lead-free solder, only leaded survives aging it seems.

author: Ian.M
author_rank: Super Contributor
timestamp: July 07, 2017, 07:16:43 pm
content: The main issue is the long term stability of the solder's flux core(s). Rosin based fluxes with stable minimally corrosive activators are long-term stable. The more active the flux is, the more likely it is to deteriorate in storage, corroding the metal of the solder wire and using up its activators. Also there's the water washable flux issue - its far far more sensitive to moisture and its residue is notorious for being corrosive.Quote from: Cyberdragon on July 07, 2017, 05:26:25 pmTektronix used to supply silver bearing solder with their scopes because they used silver plated ceramic terminal strips - ordinary solder would leech away the silver and damage the terminals, often leading to the silver terminal separating from the sintered ceramic substrate. I believe it was something like Sn:60/Pb:37/Ag:3 though apparently the original Tektronics patent specified SN:65/Pb:32/Ag:3, the key part being 3% silver to vastly reduce the tendency of a Sn/Pb solder alloy to dissolve more silver. The far more common 2% silver Sn/Pb solder was *NOT* recommended. Also the flux was specially formulated not to attack the bond between the silver and the ceramic.A small coil of solder with cut ends will deteriorate faster than a longer reel or than if its ends are melted to seal them. I'm betting that with the age of that generation of scopes, cut ends and their special flux, your Tek solder was well past its best before date.

author: Electro Detective
author_rank: Super Contributor
timestamp: July 07, 2017, 10:54:43 pm
content: Great tips, looks like a vote for leaded solder and melted sealed ends for meThat would explain why some 1.0 mm solder from the 80s still works (after a vacuum/dust off and IPA) and the joints tack quick and shine nicely,Which is why I store solder in those take away food style containers (hey, they're FREE) to keep out dust and environmentals when not in useTEK owners are in for a big surprise it seems, if they they try to use the supplied stuff in those older scopesIs that solder still available to buy new in small quantities?

author: stj
author_rank: Super Contributor
timestamp: July 08, 2017, 12:42:01 am
content: silver loaded solder is still made by company's like Stannol.https://www.rapidonline.com/stannol-hs10-sn95-5-ag3-8-cu0-7-solder-wire-520391

author: wraper
author_rank: Unknown
timestamp: July 08, 2017, 01:14:46 am
content: Quote from: stj on July 08, 2017, 12:42:01 amThat is a completely different solder. What you linked is just a usual lead-free stuff everyone makes nowadays.

author: stj
author_rank: Super Contributor
timestamp: July 08, 2017, 01:24:07 am
content: it's almost 4% silver.

author: Nusa
author_rank: Super Contributor
timestamp: July 08, 2017, 01:38:27 am
content: Quote from: stj on July 08, 2017, 01:24:07 amYou're deliberately missing the point. The point is that old Tek equipment is supposed to be repaired with the manufacters specified solder, even if it's leaded solder. They believed that so much, they even shipped some with the unit. It's allowed under EU ROHS, so it's not a legal issue.

author: stj
author_rank: Super Contributor
timestamp: July 08, 2017, 01:40:12 am
content: i never said it was a legal issue.

author: Electro Detective
author_rank: Super Contributor
timestamp: July 08, 2017, 01:46:47 am
content: If you sucked out and cleaned off the old stuff, would the pita lead free equivalent work ?Anyone have a go? or tried something else on these old tank CROs?

author: deflicted
author_rank: Unknown
timestamp: July 08, 2017, 02:47:08 am
content: I recently thought I had found a terrific score on some Kester solder at an estate sale. Only problem is the stuff is at least 30 years old, maybe even double that. I tried soldering with it and it just balls up and won't stick to anything. It seems the flux has all leaked out. I'm still hoping that if I cut off a couple/few feet of it, there might still be a good section that still has ample flux in it. We'll see. Barring that, maybe brushing some liquid flux on the components prior to soldering might help it flow better. But that sounds like more trouble than it's worth.Quote from: Ian.M on July 07, 2017, 07:16:43 pm

author: WastelandTek
author_rank: Frequent Contributor
timestamp: July 08, 2017, 02:52:49 am
content: Quote from: deflicted on July 08, 2017, 02:47:08 amGet a needle applicator bottle and some MG Chemicals 835 RA flux, stuff makes soldering a dream, changed my life

author: GreyWoolfe
author_rank: Unknown
timestamp: July 08, 2017, 03:37:49 am
content: Quote from: WastelandTek on July 08, 2017, 02:52:49 amGet a needle applicator bottle and some MG Chemicals 835 RA flux, stuff makes soldering a dream, changed my lifeThis and Kester 44 63/37 with a 66 core. I still have some of a 1 pound roll of 60/40 rosin core solder I bought in 1998. Works and wets just fine.

author: wraper
author_rank: Unknown
timestamp: July 08, 2017, 08:03:08 am
content: Quote from: stj on July 08, 2017, 01:24:07 amWhy do you think that such lead free solder won't destroy those super sensitive parts which required special solder? I don't know about super thin plated silver terminals on those Tek parts but such lead-free solders are very aggressive against copper and iron.Quote from: WastelandTek on July 08, 2017, 02:52:49 amRegardless that liquid or gel flux is a very good thing to have, it's not required for through hole soldering. 30 years is too much for flux in solder core. It has expired a long time ago. I have some solder wires with expiry date 3 years after mfg date. Others have even less, though it's not always written on a spool.

author: Yansi
author_rank: Super Contributor
timestamp: August 01, 2017, 08:36:13 am
content: Quote from: alm on July 07, 2017, 01:15:22 amUnless you are soldering the next brain for a space station, I guess.