Malfunctioning Potted Relays: Emergency Repair in the No. 5 Crossbar

[This video should be manually captioned, but as of making this public, KZbin is still trying and failing to apply them. Sorry!]
The goo has returned, and it must be banished! If you like longer, unscripted videos, then you'll love this!
Like and Subscribe if you think we're cool enough :D
The orange plastic razors I use here are very awesome. You can get them from retailers such as: www.razorblade...

[@AT_Videography]

Let me say one simple thing, if anyone here is transphobic, you're not gonna like my comment at all. First off, Sarah and Claire. You two are an amazing and hilarious duo, but seeing you two stand proud made me want to get out of my shell and be proud of who I am. It's really hard to explain exactly what comes to mind, but I really can only describe it as this: I am a proud MtF Transgender woman, my voice may not be the smoothest, and I may not have the best curves or clearest skin out on the street, but any time I watch any of these videos, it re-establishes that I'm not alone by any means, and should only be afraid of fear itself. Thank you Claire and Sarah, for giving me the inspiration to grow into the unique, and beautiful woman I am today. (My profile pic has yet to be updated, but that is coming soon) May you fantastic people live healthy and long lives, and be prosperous in all of which you challenge yourselves to. Much love! -A boy that was, But woman that is.

[@DeviantOllam]

I love learning from you and would gladly listen to your explanations of things like this for hours ☺️👍

[@tcpnetworks]

days.......

[@KeritechElectronics]

@@tcpnetworks months!

[@orto6356]

@@KeritechElectronics years!

[@DJSubAir]

Oh hey! Nice to see that you enjoy this content as well about old telephone equipment

[@DeviantOllam]

@@DJSubAir heck yes. Sarah is one of my favorite people in the world and her content is terrific. (Also, I should of course recognize that while Sarah is most typically the one in front of the camera, there is a dedicated crew of very smart individuals who make the museum run... several of whom are instrumental in these videos coming together.)

[@ennexthefox]

7:31 the excitement and energy of “LOOK AT HOW MUCH GOO I GOT IN ONE GO” has improved my mood so much

[@SplitPixl]

The trouble cards are still being used as intended, they're detecting trouble!

[@tomschmidt381]

More like displaying the trouble, sorry I couldn't resist.

[@aaronbrandenburg2441]

Yep. 😆

[@aaronbrandenburg2441]

You think!

[@AT_Videography]

I just had my eyes dilated for an exam after an accident I had, and this video being relatively low light has been a blessing. I was able to watch it without burning my eyes out while I waited for the dilation serum to wear off.

[@DMahalko]

0:40 The potting material is leaking from the two empty holes on the back of the relay. That is where it was initially filled with the potting material. Plug the holes, such as by threading the holes and inserting short bolts with a rubber washer seal. Also wrap the metal and plastic seam with a waterproofing silicone tape. US Patent 4134088 by Bell Labs - 1977 - A pair of apertures 34 and 35 provide access to the interior of enclosure 33 for the introduction, for example, of a potting compound 36, a portion of which is represented in the drawing. US Patent 2882505 by Bell Labs - 1959 - The potting composition of the present invention possesses an extremely desirable combination of these requisite characteristics. It consists of a mass of fine particles of fused alumina, each particle preferably being coated with a cured silicone resin. Bell Laboratories Record Volume XXXI No 11, Nov 1953, page 462, potting with wax using a hospital centrifuge.

[@Tom_Losh]

Every single switch I worked in had it's own personality, and a person who knew a particular switch could sense instantly if it was healthy and happy - or not.

[@donmoore7785]

As the son of a 42-year Bell Labs/WE employee who retired in '69, I have not seen a failure like the breakdown of potting of the 316 relay in all the stuff dad brought home. How insidious. As you worked on the wiring, I asked myself "what happens when the wires break?" and sure enough they did. You are doing God's work- very nicely done! ps You will never forget to make sure that spring steel is seated again...

[@boballmendinger3799]

It affects virtually every sealed WE relay ever made, from what I've seen. Even 1A2 packs... MFT's, 4ESS, D4, SLC 96... The D4 packs are great fun, as both upper and lower card guides fill up with the goo from above, and you nearly have to pry the packs out! Thankfully I retired last week, and no longer have to deal with it!

[@GothAlice]

@@boballmendinger3799a ha; so in my own comment hastily added before reading the others, signs point to potting material stability, not internal arcing. 😕 Good to know I guess.

[@vwestlife]

I also had trouble with captions on my video today. I'm glad to see I was not the only one! Fran Blanche also did a video about the green slime and how it affected the power cord of her guitar amplifier.

[@ConnectionsMuseum]

Oh, I should check that out. Also, yeah, the captions not working is too bad :(

[@vwestlife]

@@ConnectionsMuseum The captions are working now on this video.

[@DJSubAir]

@@vwestlife hey your here too? Another person who I enjoy his videos also watches these videos about old telephone equipment :) your awesome man

[@1pilotsteve]

I remember shellacked contacts..not green goo

[@lpbkdotnet]

Loved the vibe of the coffee break chat! Possible new regular video segment? The comparison with friends/loved ones was great. I’ve always found it hard to describe that spidey sense of walking into the exchange and just knowing it’s not right! Thankfully none of the strowger exchanges I look after here in the UK have potted relays similar potting may have been used in TXE exchanges over here, but being 60s/70s … those are too modern for me!

[@thomasgray6092]

Which exchanges are they?!

[@lpbkdotnet]

@@thomasgray6092 I'm part of the team that look after a UAX13, PABX4, and some home built exchanges for the Dean Forest Railway, and have 5 PAXes (ATE, Ericsson) in my personal collection... Keeps me busy! 😆

[@Ranger_Kevin]

May I say: That rainbow sweater looks absolutely fabolous :-) Also love the troubleshooting videos, I find fixing old gear fascinating.

[@hariranormal5584]

Even those glasses, I never noticed. It really does look amazing, kind of a happy smile seeing it :)

[@ConnectionsMuseum]

@@Yonni6502 I wish I could find another rainbow sweater like this. This one belongs to my partner, and I asked her where she got it. Checked the website, and they are no longer for sale. If you look at it close up, its got iridescent threads weaved in every so often, so it kind of sparkles.

[@AriBenDavid]

(I'm an old telecom guy and spent time as MTS at Bell Labs.) I am just amazed at the breadth of knowledge that you have with such a range of equipment.

[@Tom_Losh]

We used to attack messes like that with 1,1,1, trichloroethylene spray (we called it "Instant Switchman"). Black and white spray cans from WeCo by the case. The liquid also came in brown pint bottles through 55 gallon drums for when things really got serious in a #1 SXS. Thing is, methyl chloroform or fluorinated methyl chloroform is nasty stuff, even though we sometimes almost bathed in it. Hopefully there is currently some sort of reasonably safe solvent that can be used to detail clean your wire-spring relays and other gear.

[@mobile_vic]

The goo is almost certainly plasticizer. The potting compound used is likely a polyvinyl (PVC) or perhaps polyethylene (PEN), and as it ages (accelerated by heat), it breaks down into its components and the plasticizer, which is slightly conductive, leaks. The green color comes from the copper it’s leaching on the way out of the relay. Soap and water won’t touch this. Definitely try something stronger to clean it: brake cleaner comes to mind (try the environmentally friendly stuff first, and if that doesn’t shift it, try the chlorinated stuff in a red can).

[@markholm7050]

Polyethylene does not use plasticizers and would not be a likely material for a potting compound. PVC does use plasticizer, but is not a likely material for a potting compound. I suspect a polyurethane. Some polyurethanes can be cast as a relatively low viscosity fluid and set up into a much firmer solid, just what you want for a potting compound. Some polyurethanes are also notorious for degrading to goo over a long time. Plasticizers for PVC are not electrically conductive.

[@SeanBZA]

@@markholm7050 I know both those green goos, they are common in 50 year old PVC cable, where the plasticiser reacts with the tin plating and the copper. Urethane potting will also react with time, and yes the best remover is brake cleaner, but for relays much better is to use Kontact Chemie contact cleaner, or the Tuner 600, though I have had good results using Label Off 50 sprayed on a cloth and a bud, to dissolve the goo, before you use the Kontact Chemie WL wash to remove the remainder. These do not damage the varnish too much, and thus you will not be sitting rewinding 8000 turns of 48SWG wire. A hint is to get yourself an ultrasonic cleaner, and use some water in the tray, with a glass tumbler set that you fill with denatured spirits (methylated spirits) and have the relay in the spirits, then put the tumbler in the water, and ultrasonic clean for 2 minutes, then remove relay, dry with a cloth, then move to the next tumbler with clean fluid, for about 5 washes. Then leave to dry, and most of the goo will be gone. I did something similar with military equipment, though the ultrasonic was a little bigger, and we used TCE in 44 gallon drums, which was also distilled in the machine to clean the gunk out. 20 seconds to clean, and if you left it in for 40 you lost parts off the unit. But it was clean, just replace the paint. When it was time to dump the fluid all the dirty stuff like carburettors and such from the GSU came through for a wash, making all the hydraulic fluid vanish, then the old black fluid went into a drum, which was then delivered to stores, for them to figure out how to get disposed.

[@markholm7050]

@@Yonni6502 Probably not a community college or university. You need somebody with relevant background knowledge and experience. This isn’t the sort of thing academic labs work on. Also, polymer formulations, including degrading polymer formulations are pretty hard to separate into their components.

[@ConnectionsMuseum]

Thanks! The only thing I'm suspicious about is the green color--I don't think it's coming from copper. There should be no exposed copper inside of these relays, and if there was, that would indicate a coil short, which would absolutely cause the relay to fail entirely. (They are very sensitive!) We have a few hundred of these relays in the museum, and I've only ever observed one total failure, and it wasn't even leaking. I think the green is a dye. The color is way too consistent to be purely from leaching copper.

[@SeanBZA]

@@ConnectionsMuseum Well, they were filled with a black potting, which can have a green component, as it cannot be black due to the usual carbon filling, as it is conductive. Thus they used a green dye and probably a red one, in large amounts, to make it appear very dark, and this green azide dye is now leaching out dissolved in the decomposing plasticiser.

[@kencarlile1212]

Gotta say, watching you use those test frames is like watching a master organist play. Thanks for making these videos!

[@ConnectionsMuseum]

Thanks for watching. Glad you enjoy them :)

[@ViaSandee]

The Switch Witch! ❤

[@DougDingus]

When people see you use the gear, they want to experience it. Analog stuff is as mechanical as it can be satisfying. Fun to watch. And, I suspect drives a fair number of tour requests. Does anyone ever ask to run a test, or make a call?

[@xAEROPLANEx]

Sarah, Claire, Astrid, et.all...Excellent video! Thank you so much for posting. +1 on the nice sweater. :) Everybody else commenting, THANK YOU! Here, within hours, from places all over the world, there have been plenty of analysis, suggestions for repair/cean-up/personal safety, and useful anecdotes, to help with the problem and illuminate the viewership. It's very appreciated. I've been lucky to have visited the museum once, in the summer of 2018. If you get a chance to go, by all means do, it is an incredible place, and that the gear works AND is in operation for the museum goers makes it truly special. Thanks to all who make it happen.

[@moconnell663]

That goo looks very similar to the decomposing PVC that I see in molded electrical plugs from this vintage. The plastic decomposes back into liquid monomers and seeps out around the pins.

[@peterweingartner4364]

I was thinking that too... reminds me of this video from John Ward about PVC clad wire in Britain from the 1960s: kzbin.info/www/bejne/moLJfYt-rMp3rJI

[@dansummers2965]

Agreed, it looks like the same kind of plasticizer leachate that we get in old wiring installations in the UK. I wonder if the green-ness is related to its proximity to copper...

[@cameronwebster6866]

@@dansummers2965i can think of two ways to test that, one is to expose the goo to something like sulfuric acid (or some other sulfur compound that can mix with the goo) and see if you get a colour change to blue, which would come from the Cu becoming CuSO4. The second test I can think of would be to burn the goo with a blue flame gas torch, and look for green fire. Both tests require a minimum concentration of Cu (specific value unknown to me), and so can't be used to confirm an absence of Cu.

[@dansummers2965]

@@cameronwebster6866 That's a good idea. Burning an unknown chemical (or subjecting it to strong acids) is something that should obviously be done carefully and ideally with some fume extraction, but that would tell us if the green is copper or not, for sure.

[@ksavage681]

Nah, its an almost solid coolant and sound deadener. If it gets hot, it turns more a liquid and leaks out.

[@jimstewart336]

I really enjoyed the discussion on polar relays. In the summer of 1966 I was 14 years old and the CO in Cle Elum was being converted from switchboard to step-by-step. I spent most of the summer hanging around the work and begging parts from the old office. I got a bunch of polar relays and arranged them as a 10-bit memory for the computer I was going to build. The computer never got past the working 10 bit memory, but I did have a lot of fun with several different types of relays.

[@TheBarrule]

Had a goo problem back in 1970 at one of the first GSC crossbar exchanges being installed in Wales. The goo appeared under the residual studs on relay armatures causing them to stick on. The problem was caused by fumes from the moulded plastic shelf covers reacting with the stud. The covers were replaced with glass covers in metal frames and the problem was solved. The plastic covers were very popular as garden cloches.

[@IrishvintageTVRadio]

I don't know much about this stuff but I have to say your dedication to keeping this stuff working is second to none! That goo looks like a nightmare. Really well explained.

[@matthewrichardson2467]

I love how excited Claire is about the goop! Keep up your awesome work people!

[@rogerwarren2459]

sort of reminds me of a Plessey crossbar PABX in the UK I looked after back in the eighties. We never had green goop problems but during its lifetime it had a major upgrade , peformed by the factory techicians . As art of that they were very liberal with the contact cleaner spray. That as great when they were there and it was ok for about 3 months afterwards. Unfortunately the Cleaner acted as a pretty effective insulator when it reacted with some of the contacts . Kept me and my colleagues busy for months afterwards ! . Love the channel and it interesting to see how things were different but still the same over the pond

[@johnmcnamara1554]

I have always enjoyed your videos, as I used to work on a SXS in college. Your mention of detecting trouble by sounds reminds me of the most distressing telephone exchange tour I ever took. It was a Bell System SXS that had digit-absorbing first selectors. Their operation of stepping up to a level, stepping in one position, and then dropping back sounded exactly the same as a malfunctioning switch. Breaking wire-wrapped wires is also familiar. i found that the best thing to do was to quit for the day and try again tomorrow. I still believe that I saved the company money by doing so, besides saving my sanity.

[@renaudl8733]

I adore the way you show, explain, examine and do the things you do. I learn so much watching your videos. You could do a video each day and I’d watch them all as soon as they are being posted. Keep on !

[@t13fox67]

As a switching tech in the 70's, I used a 35f test set on those 280 type relays quite alot which set certain currents to the relay like "soak, no operate, soak, operate" etc. If a tiny metal burr come off between the adjustment tool and magnetic post, it would throw off the settings. Especially if you didnt see it -- like me. Fun days working on those. Thank you for the video. Excellent.

[@tomschmidt381]

Fascinating maintenance video about this old equipment. Sounds like you guys have the same aging plastic problem as NASA. Plastic chemistry delivers great products but it does not age gracefully over the decades causing nightmares for museums.

[@sueschankweiler6775]

Enjoyed the presentation! Worked on xbar over 20 years! I replaced every 280 type relay with 360s in all markers, current flowed the rest of the 280s that did not have a 360 replacement. DCT relay current flowed, very few troubles after that. Never saw any green goo! Happy to have sent you a pack of double sided cards! Worked in PTTWPAPTMG0, Pottstown PA 11:42 Feb 9

[@mnsitelecom5131]

Thank you for all you do to preserve our industry's heritage.

[@mspysu79]

Sarah, my hat is off to you and all of those that work keeping these machines fed and cared for. I know the fun of working on machines when parts are becoming unobtanium, as I am a video engineer for A/V preservation division of a large document storage company, where I deal with videotape recorders ranging from Ampex 2" quadruplex all the way to lowly VHS, I can't exactly call Amopex service in Sunnyvale or Sony Broadcast And Professional group in NJ and ask for parts and in my non day job its the same but with DEC, IBM, Apple, and other computers at a computer museum near Pittsburgh. I love the general sharing of this information that is at risk of being lost, except for the small and dedicate group of telecom enthusiasts. Keep up the great work!

[@SvenSchumacher]

You girls are really very symphatic and know your stuff.

[@davida1hiwaaynet]

Thanks for sharing this repair! I hate it when things start releasing goo! That happens with old plastics and it makes a terrible mess! Also I love your sweater. it grabbed my attention and is so cheerful!

[@five-toedslothbear4051]

Awesome pics! I really love watching these videos and learning more about how these telephone switches work. It’s an interest I’ve had for a long time. Thank you for the video! Also, deep respect for your skills and tenacity, all of you!

[@trackergeoff]

You are a great communicator. In layers. Well done.

[@2dfx]

For a decomposing polymer like that, I would definitely second the recommendation of using acetone or some other strong solvent to clean that off. Easier, cleaner too.

[@aatheus]

So glad that you share these videos. I am looking forward to visiting the museum this Sunday

[@toresbe]

I always let out an audible "oh goodie!" when I see a new upload. Aside from the technical content - I love your look in this video! Happty new year!

[@JamesBricker-lq3nu]

Have you considered using heat shrink tubing over the entire outer case of the plug-in relays? This would contain the GOO within the heat shrink tubing. Simply remove the relay, apply the heat shrink, plug the relay back in. Hope this helps. Great videos. Just discovered your channel.

[@spaceman7832]

Speaking of the TS1 relay, it appears that contact 6m is closed (23:24) which should not be since the relay is not energized. I absolutely admire you repairing that wire spring relay. Disassembly and reassembly of that thing isn't easy. Love your videos. You do a great job of explaining these switches.

[@dennissmith8199]

These are great videos! I knew that the telephone network was complex, but this is amazing. Also amazing is your, and the other's knowledge of how these systems work. Keep up the great work. Too bad you're on the west coast, or I would definitely come and visit. Bravo!

[@CONCERTMANchicago]

_🎼 When the world is running down, 🎵 you make the best of what's still around 🎶_ *_Thanks for bringing everyone along for the ride_* Most everything back then was made to be fixed. So I'll definitely agree with you it's better to Repair than replace with all brand new stock that is no longer manufactured. After all we want our great grandchildren to see this system still fully functioning and another Century or two.

[@wcemichael]

Take out your leaky relays, clean them up, scuff them up a little bit and apply something called "shoe goo" around the area to seal it. Shoe goo is like a cross between caulk and super glue. I sealed a bike tire with a large hole, with nothing but shoe goo 3 years ago and it's still holding air. I also patched a few holes in my inflatable hot tub. I patched a pinky sized hole, it's been holding for a year now

[@bboogaar]

In my years working on Northern Electric #5 Crossbar switches I don’t ever recall seeing the green goop. But I do remember the polarized relays.

[@martinwragg8246]

Maybe an ultrasonic cleaner with WD40 or similar solvent instead of water. You may even get away without disassembly of the springset. I worked in the UK back in the 70's on crossbar TXK3. Loved it ! Keep up the great work. 👍

[@simonbullimore1807]

i love these troubleshooting videos they are so damn interesting... every step explained so expertly. Oh and I love the rainbow sweater too.

[@matthewhopson964]

Thank you for making these videos, they give a look into a world which to the lay person seems like magic.

[@tkimble6210]

When I worked at Chicago #1 telegraph I had the opportunity to "box" polar relays, specifically the 209A type. It was a delicate job and a "few" relays found their way to the Chicago river. The mercury wetted polar relays were a godsend. When they acted up you just pulled them and tapped them on the floor and they were good to go.

[@HandFromCoffin]

I love these videos keep making them. This electric mechanical machines literally fascinate me. "it's good for 20-30 years then you order another" 70 years later.... Telling grandpa about the leaking caps issue in the 2000's... Ha, son back in my day we'd just grab a card... EEEH! I love how you hint on pricing! You are talking about it in a "how long should it last" situation but you're also figuring out the budget for the design of the system and the cost the phone companies are willing to pay. Even if the 5 year ROI rule wasn't around then the idea would have been. How much cost? Take the max number you predict the phone companies are willing to pay times 5 years and that's the cost of the device. It sounds like for phone systems it might be longer or not work out like my example for other reasons.. but that is how I've seen the cost of a product be calculated (basically).

I reckon there must be a liquid you could immerse the relays into to easily dissolve the goo. Then it would just be a matter of using contact cleaner on the contacts to remove any leftover traces. Acetone is harsh, but only on some modern plastics. It evaporates quickly and is cheap. Any other cleaner recommendation for full immersion?

[@APWaddington]

Once again thank you for a very informative video on the care you give your big loved on that sometimes gets unwell and makes not so nice sounds or none at all in this case

[@Screamingtut]

I worked for Nextel as a contractor back in the early 80s as a trunk room Tech (my dad used to work for them too & got me the temporary job) so that green stuff, if I remember it is inside those cans as a vibration insulator to contains the mercury-filled glass microswitches

[@MichaelCowden]

I would love to take a trip to Seattle and see the Museum and meet Sara, Astrid, Claire, and the rest of the team. Analog phone technology has been fascinating to me for many years, and I'd love to pick your brains and see all this equipment. Do y'all (I'm in Asheville, NC) offer personal tours in blocks of time? Thank you all so much for a) building your knowledge of equipment like this, b) making the videos about it, and c) sharing your knowledge and time with Museum visitors.

[@tookitogo]

I’ve had the same thought: I’d love to visit and hang out with them!

[@gman6081]

Amazing video. Hard work troubleshooting & repairing on the fly. I only detected one damn-it while making that repair in connecting the terminals.....there would have been many more expletives coming out of my mouth and many more blown fuses. Thank you for sharing. Wishing you success in maintaining and preserving this piece of our communications history.

[@wtmayhew]

That goo is like a green version of “icky PIC” moisture displacement compound from the inside of cables. I don’t know what the stuff is, but Western Electric sure succeeded in making the most tenacious obnoxious compound I know. There’s d-gel and some of my friends recommend De-Solv It for icky PIC removal. I’ve used De-solv It for removing tape reel and disk labels to good effect.

[@micahnightwolf]

Where did you get that rainbow sweater? I must have one!

[@roberthart8933]

I really love the rainbow jumper. I also have a rainbow jacket. I hope the green goo is not toxic. And I’m impressed by the rigorous troubleshooting methods. The wiring looks almost impossible to figure out.

[@scottthomas3792]

A lot of early 1960s plastic turned gooey with age...early PVC, I think. I've seen molded cords and plugs in older appliances get gooey, though not green. These are great videos!

[@erg0centric]

As someone who has worked on old electronics I want to ask, is it carcinogenic or mutagenic? What does it taste like?

[@DoccieDraaiorgel]

If I didn't live ya know, on the other side of the /world/, this is exactly the kind of museum I'd love to volunteer at. It's all just so incredibly interesting!

[@bobpatrick7152]

nice job repairing the wire-spring relay keep up the great work

[@PeterHarford]

We find this Green Goo in the Uk on PVC cables manafactured in the 1960's I understand its a "degraded di-isoctyl phthalate" that was used as a Plasticizer on the Sheath. I used to work on Crossbar systems in the 1980's and haven't seen it on relays but like you say its past its sell by date.

[@KeritechElectronics]

Hard candy, you say? The goo looks kinda like the LT-43 bearing grease we use here in Poland, only it's sticky a.f. rather than being greasy, haha! Repairing rather than replacing is what I also did when I worked for the Book Art Museum. Taking a deep dive, getting your hands dirty... that's how ya learn how things work, right? No matter if it's a phone switch, or a Monotype caster, or an old radio, or an IBM Selectric typewriter... Old tech is fascinating! Keep up the great work

[@z06rcr]

Have you thought about experimenting with a sealant.. perhaps a spray of a thin layer of clear rubberized coating on the leaking relay to forestall future leakage. Not sure if it would work but might be worth a try on one or two relays as I don’t see a down side.

[@robertnicholson7733]

Ahh, polar relays, i have serviced and adjusted so many, they were used in telegraph systems for the 50 or 75 baud signals. These were usually quite reliable, although I once worked with someone who wasn't very good at anything, he put the wrong length screw in the contact set of the transmitter of a Siemens Tloch 15A. This shorted the polar relay from hard 50V to earth, he plugged the machine in and turned it on, 10 seconds later clouds of smoke started pouring out of the relay set under the machine counter, 1 amp through a polar relay will do that. I also worked on Ericsson Crossbar exchanges, they used Claire relays for the telegraphic signals. These mounted on an octal socket and were the shape of a signal octal valve but in a metal can. They were very reliable, but when one started to play up, you unplugged it, dropped it on its base (a couple of inches), dropped it on its top, and dropped it on its bottom again, usually success! Even though it is a different crossbar system, the names used in this video are bringing back bad memories!

[@kreuner11]

I wonder, if you run out of trouble cards do you have some sort of recreated template you can send to a print shop and get a fresh batch?

[@3Cr15w311]

I've been watching a lot of your videos lately after discovering your channel. Cedartown, GA where I went to school grades 1-11 and where my father taught was on Bell System and they had a Number 5 Crossbar starting in 1961 when dial service was set up (748 which was likely going to be PHilpot 8) had they not already been moving to all-number at that time. I got to see the No. 5 Crossbar on a field trip once! I lived in Cherokee County, AL where we had an independent non-Bell phone company and they had a bunch of Stromberg Carlson XY exchanges all over the county (do you have any of those at your museum?). We had WAlnut 7 (927) for Centre, GReenwood 5 (475) for Whorton, LAkeside 6 (526) for Leesburg, LAmbert 3 (523) for Sand Rock, JAckson 4 (524) for Collinsville, LAwrence 8 (528) for Crossville in 1956 when dial service was set up there. SPruce 9 (779) for Cedar Bluff and GArden 2 (422) were added in 1957 when that phone company bought out the one in Cedar Bluff. I believe that all of these were Stromberg Carlson XY. It was long distance to call 1.5 miles east of where we lived since 777 (which likely was likely to have been SPRing or SPRing 7 if all-number wasn't becoming a thing in 1961) was in Georgia. They probably had a 355 step system and I guess that due to how the dial tone sounded on a funky old post-pay coin phone at the state line that may have had a range extender on it due to some funkiness with it. It sounded different than any other phone I ever used. It was local to Cedartown and Rome though. South of us, Piedmont covered part of the county with GIbson 7 on Bell so it was long distance to call Spring Garden School where some students in my area went. I went to Jacksonville State University and that town was HEmlock 5 and Anniston south of there was ADams 5. I totally love your channel and your knowledge and it makes me with I could go back to the 70s and 80s and record a lot of the sounds from phones during that age. I love your colorful striped shirt and style as well!

[@spugintrntl]

I encountered a goop nearly identical to this coming out of the green wire insulation in a vintage polymoog... It got into all the wire harness plugs and I have yet to find an effective way to clean it off the contacts. I guess I'll have to try goof-off!

[@PINKBOY1006]

Decided to check my 1A2 cards in my KTU and lo-Behold one of my 400D cards from 1973 is leaking the goo from the 327A ring up relay. It really must not be conductive because its working fine still. And as a total side note, the green goo has appeared on several AC line cords for my AT&T Genesis phones (western electric made). When I cleaned them 99% alcohol barely touched it! but since it strongly resembled the "green goo" it probably is a plasticizer like others have noted.

[@xyzrandom3981]

What a fantastic video. Thank you so much for taking the time to make this

[@AmauryJacquot]

would cleaning the relays in an ultrasonic cleaner full of solvent (spirits, Isopropanol, ...) work ?

[@azpcox]

Where do you acquire working 316 relays today? How do you replace other relays if they break? Love learning about the old frames!

[@dougn7bfs]

The green 'goo' is the result of the decomposition of some sort of polymer inside of the relay, it's green because it's reacting with something copper inside the relay, and sadly because of that, it is relatively conductive. I would think that at some point the relays that are leaking this goo will become problematic in their function and will need to be replaced but you probably get that much. Luckily at least they aren't filled with PCB like some old transformers were... Visiting your museum is still on my bucket list, I'm only 4.5 hours away drive-time, hope to make it some day. Thanks for sharing

[@ds99]

Holy smoke what a pile of knowledge you require. I think it’s also clever to repair what you can seeing as these parts are no longer being manufactured. It’s so good that you’re able to do that. That green syrup is weird. Why would they ever pour that into a switch? Maybe it’s used as a coolant? I don’t know. Nasty stuff. Thank God for the test cards!

[@NVIN-ov9dn]

Instead of goof off try an automotive product known as Brakleen its is an aerosol spray but cleans the green goo up extremely well and is safe on plastics. Make sure the power is off on XB as it is may flash on you. If you are dis assembling the relays to clean them you can use lacquer thinner as well. Both products put off fumes so make sure you use ppe.

[@tshackelton]

Brakeleen is awesome but it's NOT safe for all plastics....

[@kevinmartin7760]

@@tshackelton ...and you definitely don't want it dissolving the lacquer insulation on the coil windings!

[@ConnectionsMuseum]

Brakleen is a good idea, yeah. I used to be an auto mechanic, and used the stuff all the time. I find that Goof-Off (specifically that brand) works really well, and I know from experience that it doesn't damage the plastics in the relay.

[@TurboTimsWorld]

Just seen an early video with the England phone box you have there, is it still there can we dial it from the UK, can you do an update video please.

[@XbotcrusherX]

Especially given the era, you might want to send a sample of that off for analysis. They had a number of quite nasty plasticizers back then, and even if not, it would probably give you an accurate picture of what solvent might best attack the goo.

[@jimurrata6785]

Seems to me that an ultrasonic tank could clean those open relays without disassembly, saving hours of frustration. They are certainly not too uncommon or expensive today. I can't say which surfactant or solvent would work best with your plasticizer while keeping the fumes and fire hazard to a minimum.

[@BVN-TEXAS]

As someone who works around old mechanical machines some dating back to 1940, I can agree, you just know from being around it and how it “talks” to you.

[@jonpattison]

Please be careful with the goo! I don't know about this goo, but similar goo used in transformers of that era used Polychlorinated biphenyls (PCBs) as fire retardent - nasty stuff!

[@davidanderson5310]

Neat! This is the first time I'd heard of a potting compound that wasn't a solid.

[@tookitogo]

It almost certainty _was_ a solid when it was manufactured!

[@edgeeffect]

You're slowly turning me into a telecom nurd... but I was already a chemistry nurd... I need to know the composition of the goo! ;)

[@GrumpyUnkMillions]

It seems you can hear the difference between a well-serviced switch and one that has had a lot of toothpicks to block troubled lines. In retrospect it was disconcerting to walk through a 4A/4M switch when new to Long Lines. Some of the equipment used to make connections was astounding at the genius minds that were able to make mechanical things jump up and down, shine light, and cause a connection to be selected. Hearing the relays clatter and the steppers move up and down, then rotate, was overwhelming to consider how well it worked given all the moving parts. I heard of the 'trouble ticket' machines getting blitzed, punching cards as fast as it could until the supply ran out when a particular thing broke, never observed. Watching brings back memories from the mid 1970's. "Came clear while kicking bay" on a ticket... popular solution. Meant to add, you could try using 'pig mats' cut into strips of appropriate width stuffed under your leakers. The material will absorb a LOT before they have to be replaced, and they are not real expensive. tom

[@sparkyprojects]

Is there any way to seal the back of those relays ? If you're worried about pressure with heat, maybe carefully drill a hole in the front You should get that goo tested, not only to make sure it's not toxic, but to find out if you can use a solvent, even going as far as dunking the relays in the solvent to clean them. I used to install and test crossbar exchanges in the early 70's in the UK, ours were in double sided racks, the shelves hinged down for maintenance The first exchange i worked on had 5 floors, gound floor was MDF, batteries etc, it was a new exchange building with plenty of room for expansion., i knew that electronic exchanges were coming in I recently found out that the exchange has been converted, the top floor is now residential flats

[@businjay]

Love your Videos. just found them recently and subscribed. Nice to know there are some other Family nerds out there :-). Happy New Year!!!

[@danielbottoms4548]

Can you take the non leaking relays and epoxy all the possible points of leakage?

[@RingingResonance]

19:00 it's the same with bowling pinsetters. I could tell from across the building if a machine was acting up just by the way it sounded.

[@Bubu567]

Any idea what the goop is? They used to pot things in tar, and this looks like some kind of replacement for tar, which clearly isn't as stable.

[@ElectricEvan]

Could you please make a video or post something about the original price of each of these machines vs intended operating life and operating costs vs what that meant in terms of design decisions?

[@laptop006]

Next time you have an Australian through the museum (hopefully me, but I doubt I'll be lucky enough to get up there this year) ask them about Telstra's water sealant from the early-mid oughts that went conductive over time.

[@GothAlice]

That goop. Is familiar. If they’re solid resin potted, that may be the result of an internal arc melting the potting material! I’ve seen it in (much smaller) relays. It’s a rather dramatic-and gross-failure mode. If the resin isn’t particularly stable-and what is over these time frames?-simple decay may cause them to leak. I think I also saw this happen to EEVBlog at one point. 😐

[@steve94044]

I think I’ve seen that in some 1a key systems. Also western electric has a division called “blue streak” they made custom circuits at customer perm’s. These relays were also used in this blue streak equipment.

[@andromedaturnbull3512]

Thank you for another excellent video, Sarah, Claire and Astrid. May I ask if you have considered some kind of method of sealing the base of the potted relays proactively to prevent the green goo escaping in the future? For example, I wonder if it would be possible to use silicone, varnish or a gasket around where the socket meets the can. This would surely be better for protecting the long-term preservation of the switch components and prevent similar goo nightmares in the future. Alternatively, it might be possible to 3D print some kind of goo catcher widget that can be fitted to each relay if you think there is a negative consequence to the goo being kept in the relay rather than being allowed to drain.

[@randycarter2001]

Have you tried solvents like isopropyl alcohol, toluene, or flux remover? These are safe for most electronics. some paints or inks can be damaged.

[@SteveHartmanVideos]

I ran into the same exact goo when I took apart an old telephone handset… the old kind made out of that impossible to break plastic with the rotary dial on front… I remember, taking apart the mechanical, bell hammer and bells, and the inside one of the circuits was a metal Relay looking device with a hole and I stuck my screwdriver in there and out came a whole bunch of that same gooey stuff. This happened to me probably 25 years ago when I found an old phone at my parents house and took it apart.

[@Tims_Projects]

Does the goo go more liquid with heat? Perhaps those relays that it leaked into could be placed in an oven over night, positioned so the goo runs out?

[@gordonconway1140]

In my job we had a green goo problem from tape machine pinch rollers that were made of neoprene that is unstable chemically and degraded from a solid to a green goo after a few years.

[@mbainrot]

For gloves, not sure if they're compatable with whatever that goo is but Ansell Microflex 93-260 are pretty damn durable but still reasonably tactile, they are pretty damn pricy (around $60 AUD for 50 pces) but atleast for me they work super good enough for bulk photography chemical handling and nitro glow motors

[@maxmyzer9172]

9:42 i suspect its for isolation or cooling type of application, but yeah, the actual substance is probably just a dielectric that WE bought. It probably just expands more than it is supposed to

[@FruitMuff1n]

19:50 I appreciate your love and knowledge!

[@unmountablebootvolume]

I don't know when I've last seen this stuff, but I certainly remember it as being absolutely disgusting and a HUGE pain to clean up. I feel sorry for anyone who has to deal with this stuff regularly! I think I once had a bad transformer from a water boiler control (that even was quite new, like less than 30 years) that leaked a brown version of this gunk, and another older transformer that leaked the same green gunk. In european HVAC, this sort of issue is actually not even that rare while the equipment is still in use, as stuff like pumps, radiators and boilers is usually run until all spare parts are used up or it fails from old age, and many plastics, capacitors, hoses, etc... are not meant for 20-50 years of nonstop use in extreme heat and vibration, so decomposing plastics, cracking hoses, dry bearings, leaking O-rings, glue peeling up and other fails and breakdowns related to polymers aging and decomposing are kind of common on older heating systems. In fact, they are usually the main reason why an old boiler is eventually replaced, as these problems just become too common as the thing ages, and reliability thus also gets worse over time, until the owner gets fed up with the constant breakdowns and gets it replaced.

[@JessHull]

Weird! I have some old (50s-60s) tube equipment and some of the wires will leak a green goo that looks basically just like that!! I always wondered what it was. Its super reactive to other plastics and if gets on any plastic it eats right through it if left on too long. I've thrown things away because it was destroyed by this goo.