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

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

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

(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.

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.

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...

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.

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.

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!

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).

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

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.

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.

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.

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

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.

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.

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

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.

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.

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.

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

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.

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.

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

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

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.

You girls are really very symphatic and know your stuff.

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 !

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.

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!

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.

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

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

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!

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

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.

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.

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!

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!

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

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.

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

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

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.

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.

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

_🎼 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.

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

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!

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

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

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!

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.

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. 👍

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.

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!

1. Agree with brake clean and crc products 2. I can smell the museum source: working on aged electronics in the chemistry department at a major university.

a big fan of the make a cup of hot beverage and just chatting style videos.

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).

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.

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.

12:31 - You can MAKE a jig for those pretty easily out of WOOD and small metal brackets and a dremel/file. If this is routine for the operation of the museum -- i'd recommend making one, and then possibly CASTING one with resin / metal.

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.

"And that's not going to happen today." I don't know how many times I've said that at work.

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

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

19:50 I appreciate your love and knowledge!

Got the info in that goo... diisooctyl phthalate. It is a product of PVC insulation and /hot/ copper.

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

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.

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!

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

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!

Thinking about how the late '80s PCM switch I used to maintain didn't leak any green goo, but it had a lot of parts that we couldn't do anything to repair, like custom ASICs and ultra-rare LSI chips.

I can certainly understand being conservative about spare parts, I have a good stock of wipers and cords for my SXS but it's always on my mind that what I've got may be all I'll ever have.

@6:20 my brain is hearing "Chitty, Chitty bang bang, chitty chitty bang bang..." And then I broke out into song for obvious reasons. 😂

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

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.

Love these tutorials.

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

Sound in tech from the 1960's and before is always going to be one of your first indicators of a problem. I know several soldiers from the 1980's who were working in microwave relay trucks supporting Tropo Scatter radio systems who would often sleep in their rig's simply because it was going to be warmer than the tent on that hilltop in the middle of winter. Universally those who experienced a failure of a transmitter that happened while they were asleep, reported that the first indication that they had that there was a problem was not the transmitter shutting down, or fans failing (the equipment had a lot of high flow fans, which were as loud then as the cooling system for a crypto-mining hut are today.) No, the thing that woke them up was the relay for the alarm circuit for the radio detecting a problem ticking over. The next should that would be generated was the horn that you would expect would wake anyone in the rig, but as I say, every one who was asleep when one of these things tripped reported that the noise that woke them was t he relay click. They were wide awake before they heard the horn. If you were awake, then the only thing you 'heard' was the horn, but when you're sleeping, your subconscious filters out the steady noise better than any pair of sound canceling headphones ever will. That said, if you're in a room of teletypes, or relay operated equipment like a phone system, the noise of the mechanical bitss will tell the experienced operator if the equipment is healthy and happy, or not. I have thoughts on why these relays were potted, but no experience, so I'll shut up now and listen. :-)

Watching Sarah Dance accross that test frame, reminds me of the STNG scene with Data "Life.. forms.... Tiny .. little ... life forms" ...

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.

23:40 ouch, all that work... Love these vids

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

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!

I believe the green stuff maybe part of the PVC plasticizer leaching out we'll each out of vinyl extension cords vinyl wiring inside household walls

17:02 - I would 100% take measurements and readings of EVERY aspect of EACH relay and have an inventory of the types and specs. Then you can "jerry rig" a replacement if you need with a "socket" if you ever run out. Because trace length doesn't matter in that case, you can easily make a daughter board for each relay socket, and then retrofit a spec-wise equivalent relay/solid state device if you ever need to.

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.

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.

Thank you!

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.

Q: Where do telephone museum curators store their old relays? A: In their trunk. …Sorry. The green goo, btw, is from the Cretaceous period. 🦖 🦖 It’s just trying to find its way back home. These chill miscellaneous repair & maintenance videos are awesome! If you post them, I will watch them. (And find a way to turn them into dad jokes)

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

love the sweater!

I had same issue with a similar WeCO 314R sealed can relay I found it in my electronic shop inventory still in the box! NOS. It's a substitute for a 255A Polar relay found in model 15 and 28 teletypes. Green goop!. Thank G-d it was in a plastic baggie. Acetone cuts it well. Also WD-40. Use WD-40, then degreaser like used to clean engines or brake rotors. Home cheapo to the rescue. I just discarded the relay. Big mess. ST

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

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.

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