Engineer used welding shop air hose to 'clean' PCs – hilarity did not ensue Welcome again to On Call, The Register's Friday column in which we take great delight in telling your tech support stories – mostly the ones involving bizarre behavior and heroic fixes. This week, meet a reader we'll Regomize as "Wilson" who once worked as the boss of a welding shop attached to an engineering consultancy. …
One of my sisters in law. Degree in technical business administration. Complained her electric blanket did not reach to warm her feet. I suggested she placed it lower on the mattress, as the underside of the pillow needs no heating.
Once claimed she was financially independent, because: husband earns enough for the both of us. (Divorced now)
Claimed all the food in India was the same everywhere.
"Well, I should now, I lived there for a year" (In one city only)
'What did you eat there?'
"Our cook made potatoes, meat and vegetables"
That's a bit broad. The university I went to rightfully recognized that there was no science involved in what other schools call "Political Science", and therefore named the department "Political Studies". Whatever you make of the grads of such programs, the curriculum gave graduates a solid foundation in history, political philosophy, economics, and a bit of math. Nothing useless.
An ex-colleague claimed (correctly?) that any subject with "Science" in its name wasn't, and any degree from it could be ignored. He was a biologist. A major part of his work involved blood groups - but, he was a fervent believer that evolution was a dangerous sin as the "truth" was in Genesis Chapters 1-2 KJV.
I had a colleague with a PhD in biochem from a religious, but well regarded, institution. We were discussing our degrees, and I mentioned I had studied the period on Earth more than ~2.5 billion years ago. He stopped me and asked how old I thought the world was. When I told him, he went to his computer and googled it. Then he asked me about humans, I gave a less certain answer and again he googled it. Then he just said "huh.", and I quickly tried to change the subject.
Very nice guy, but that was one of the most uncomfortable conversations of my life.
If you're ever in a place where it becomes unavoidable, you can point out that science has plenty of proof that dinosaurs did[0], in fact, exist, but the religious people of the planet (ANY religion!) have absolutely zero proof of the existence of God.
[0] That reminds me ... I have to get a couple turkeys into the smoker.
Well, they often claim that something as complex as life on Earth could only be made by God. Or by aliens. Then you have to explain the aliens, though.
Earth's collection of living things is complicated, but I'm prepared to say that it just grew that way.
If the emergence of humanity is a million to one chance, then why are we here? Well - if there are a billion eligible planets in the universe for the million to one chance - not real numbers - then it will happen on one thousand planets. What's the chance that the planet we are on is one of those, out of the billion? It's one, certainty, because on the other 999 million planets, there's no one there to have that discussion.
Why is the Moon the same size as the Sun, so that there are eclipses? I think there isn't a reason but also it isn't something that God claimed to have done for a religious purpose. But in a future religion, it will be included, or perhaps it already is included in some cult or secondary revelation.
Things like that.
When I was a kid, my mother's boss had a degree in geology, but he couldn't write a cheque or drive a car... My mother used to write (and sign) all of his business and personal cheques for him.
He did eventually pass his driving test, bought a Porsche and then did a trackday at Silverstone and promptly drove it into the nearest crash barrier!
My father told a story of when he was in university in the early 1960's. His business school was neighbor to a VERY prestigious engineering school. He was walking through their parking lot and encountered one of the smartest engineering students on campus in tears next to his car because he had a flat tire and could not figure out how to change it despite the very clear, step-by-step instructions pasted on the underside of the trunk lid. He wasn't physically disabled or anything, but he could not wrap his straight-A, PHD head around that task. Dad would have changed it for him, but he was late to one of his 4 jobs he needed to pay for school.
I've used the high pressure hose from a welding shop, but it was the pure air one, and I got the correct adapter off the production manager to use it as an air gun. Luckily the workshop had an outdoor area and I used that, the amount of dust it shifted was impressive... BUT, I made sure it was just air and I the nozzle a fair distance away from the motherboard, to test it first. I also use pens or screwdrivers to block fans, so they couldn't spin to excessive speeds and break the bearings or mountings.
It worked really well. But I would never grab a random hose and start spraying!
MCAS might have been OK if:
- Pilots were made more aware of it
- Training was made available to show pilots how to recover if it started misbehaving
- The aircraft were fitted with redundant angle of attack sensors so a single point of failure wouldn't totally bork things
Decisions were made not to flag the changes or offer training as it might risk the type certification of the newer variant planes. A decision was also made not to fit redundant sensors - presumably because of the cost of the sensor hardware and of integrating software for multiple sensors. I doubt the final decisions on these matters were made by the engineering department.
The lack of that second sensor and clear indication of a disagreement between them still leaves my mind boggled years later.
Every other sensor and safety adjacent (let alone critical) system in aircraft for about the last 50+ years has at least one redundant system and indicator, and are specifically designed so that it's relatively easy for a pilot to know if there is any difference in the readings.
They threw away half a century of safety lessons and never considered there were reasons for them.
I'm not a pilot, have never had any training in it, but even I was aware of the reasons why every system on a commercial aircraft tended to be at the bare minimum duplicated, with critical ones (such as instrumentation and controls) often having 2 or 3 backups.
Third. Third sensor. The B737 has two AoA sensors, one on each side. MCAS would switch between them, one flight the one, the next the other. A third sensor would've allowed for a 'quorum' style reading. That's where the flaw was (and the switch back and forth). Gotta love bodge jobs.
I didn't know it switched between them at all. That... makes it even stupider. Someone knew there were two, was assigned to write code to use both, then... assumed there would never be an in-flight failure? During the only time the part is undergoing rapid temperature change and mechanical stress?
Even without a quorum, it's still possible to detect most failure modes in a single sensor by combining the input from the second with other data (e.g control surface orientation).
There were 2 (presumably very expensive) AoA sensors _physically_, but MCAS only used data from one.
The FAA mandated both a third AoA sensor and a software update to utilize all three to reject input from a failed one before the aircraft were returned to service.
Edit: There probably should have been 3 in the first place for quorum-based control (the gold standard for this type of problem), but 2 can work in most situations with an algorithm to detect and reject suspect input (e.g if control surfaces have changed orientation and one sensor shows no change to AoA while the other does).
"MCAS might have been OK if:
- Pilots were made more aware of it"
That was the primary issue. Pilots made aware of it means training. The 737 MAX was sold to airlines on the "common flight deck". I.e. your pilots will need none of that expensive additional training. Add any training requirements and Boeing would have had to reimburse customers for the expense.
Just because that's what the airlines wanted doesn't mean that that's what the manufacturer should do. The active deletion of MCAS from training manuals and materials was a massive problem. Same with the AOA DISAGREE indicator that was provided as an option.
There were decisions made by Boeing that were so fundamentally wrong in the pursuit of profit. They deserve every bit of criticism because they abandoned their engineering principles.
The interesting thing is aircraft manufacturers have fitted systems like MCAS on planes years, even decades before, not just Boeing, though I did not research if they had any specialized training for pilots to deal with system malfunctions. But in any case MCAS's flawed implementation made what could've been a helpful system into a deadly one.
"Airbus aircraft, such as the A320, use a more comprehensive "flight envelope protection" system integrated into their fly-by-wire controls. This system uses all control surfaces to prevent the aircraft from exceeding safe operational limits.
Boeing’s Speed Trim System (STS): On older 737 models, the Speed Trim System performed a similar function by automatically adjusting the stabilizer to assist in manual flight, though it was less aggressive than the original 737 MAX MCAS. "
Pilots were shown how to recover if it started misbehaving but 1) only after the Lion Air crash and 2) the manufacturer's instructions on what to do in this case didn't work, hence the Ethiopian Airlines crash.
The same AoA sensor fed into the autospeed so that when it failed, the aircraft never throttled back from takeoff thrust. The resulting overspeed made the manual trim setting require more force than two humans working together could generate.
MCAS would have worked if it had been designed safely in the first place, and if an independent engineer had been required to certify its safety before it was allowed to fly the first time.
I call bullshit on this.
Welding shop and workshop air is usually as clean and dry as it's possible to make it, if there's any oil or water in it then something has gone badly wrong.
I've cleaned *many* PCs in utterly filthy workshop environments like welding shops with compressed air and a blow gun, I've *never* blown chips out of sockets or damaged anything.
you need clean / dry air for things such as plasma cutters and painting
but for air tools such as grinders / drills / etc it is common practice to inject oil into the airline to lube the tool
the water in teh airline comes from not having an air dryer (and probably not regularly draining the air receiver tanks)
Fair cop, yes, oil injection is used for air tools, but as we both said, if there's water in the lines something has gone badly wrong.
One of my past jobs meant I worked on PCs and other electronics in hundreds of places that built things like narrow boats, bridges, repaired cars, HGVs, earth moving machines etc. and I have never damaged anything by cleaning dust and other crud (often mouse shit) out with shop air.
Maybe I got lucky but the numbers suggest not.
You were probably not stupid and used the air at an appropriate distance and not trying to find out if you can run the pc by back feeding it from spinning a case fan, or other such hilarious adventures. a small amount of oil and even water in a line is unlikely to actually damage most computers
I may be wrong, but I believe that one type of electric motor utilises electromagnets for both the stator and the rotor. For these you need to energise one of the sets of magnets, otherwise there is no magnetic field for wires to be moving through.
I full expect to be corrected if I have misremembered.
utilises electromagnets for both the stator and the rotor.
The reason "brushless" motors are common now for 'cordless' tools is the development of 'rare earth' magnets. (Which are smaller, lighter, stronger and just better).
Rare Earth Magnets are one of the reasons 'rare earth' mining and processing are of strategic importance.
Back in the mid 70's the ~10 year old me received an "electric kit" that included a build-it-yourself a 3-pole electric motor from scratch: even metal plates and paper to build a rotor and lacquered wire to wind your own coils.
As one "experiment" you replaced the magnet with an electromagnet (pre-wound, thank god) fed from the same power supply. Regardless of which way you connected the power, it ran the same way.
I always wondered if it would work from an AC supply but my parents were adverse to letting me connect to standard UK 240V mains!
> if it would work from an AC supply but
Yes, it could, and this is a "Universal" motor. Widely used for years in sewing machines, vacuum cleaners, and hand drills(*). Before large permanent magnets, car engine starter motors. High (and controllable) speeds, high starting torque, not too complicated or expensive. Noisy and sparky. A pure for DC motor will want laminated core, brush shifting, and other minor details for best work on AC or AC/DC.
(*) Power tools often rated "AC only" but the motors were fine on DC. The switches didn't last because the off-arc didn't stop 100 times a second on DC. Heavier switches could be had, but not at low-low-low price.
"I always wondered if it would work from an AC supply but my parents were adverse to letting me connect to standard UK 240V mains!"
Ahem, I found not asking always worked. The motor burst into a shower of sparks and flew across the room after the power wires melted. I think I was 12 at the time. It didn't trip the fuses and the parents remain completely unaware of it to this day.
Really.
The oil deliberately, to lubricate the tools being driven by the air (drills, for example).
The water because when a gas expands fast (like maybe when you blow it out of a hose), it gets colder. Google "Joule Thomson effect". Any water vapour in the air will, when it cools, condense.
IF you really really need the air to be dry (e.g. for a plasma cutter) then you can put a thing in the line to achieve that... but if you don't really need it, you just compress ambient air, which might be quite humid, depending on the weather that day. But if you're just driving a hand drill and you've got a bit of oil in there, well, the water isn't really a problem.
BUT... this is why you VERY CLEARLY label the (possibly) multiple air sources. You don't want to mix up the plant air and the breathing air, for example.
In 2017 I used a workshop to spin up a fidget spinner. Got it up to quite a few thousand rpm, made an excellent noise. I eventually dropped it when it started getting hot...
"In 2017 I used a workshop to spin up a fidget spinner. Got it up to quite a few thousand rpm, made an excellent noise. I eventually dropped it when it started getting hot..."
I had a friend who had a Snoopy / Red Baron dog house (complete with propellor) attached to the handle bars of his motorcycle.
One day he caught something in the corner of his eye and felt a slighty bump on his arm. It was only when he arrived at his destination that he realised it was the propellor that had melted and fallen off.
My brother had a wasp enter the sleeve of his denim jacket, then proceed to sting him several times between forearm and arm pit! Emergency stop followed by discarded jacket!
Mine was hitting a wasp at low speed, only to have it make its displeasure known stinging me through my denim jeans about two inches away from my lower brain!
Another time I must have had one hit my neck at low speed. The first I knew was when it crawled up my visor ..... on the inside!
Full face helmets. Good Idea. Bought one after going into small hail storm wearing open face helmet with goggles. Subsequently belting along country road on my Kwaka death machine (loved its acceleration) when I went thru what appeared to be smoke. Wrong guess. Bee swarm. Fortunately wearing full face helmet and heavy leather jacket with thick furry collar. After loud hail noise subsided looked in mirrors to see a brief head and shoulders cutout in swarm. Nearly fell off laughing. No stings either. As for birds, high speed, country road run hit a bird, probably pigeon sized hit mid chest. Painful for me, fatal for bird. Even plastic zips are hard at 100 kmh. I digress. Always used vacuum cleaners to clear out computers with dirty interiors except one back from a basement in Beijing. So unbelievably dirty even opening case blackened ones clothing. Used dry air compressor in car park to remove worst of it before using vacuum cleaner in open air. Amazingly computer still ran before and after cleaning. IBM small AIX servers in 1990s were amazingly tough.
You're lucky it wasn't a really big rock.
I saw a pickup truck with a really, REALLY bad rock hit. They were lucky that it hit the pillar on the passenger side of the windshield. The pillar was dented in maybe 2 inches deep. So maybe a football sized rock. If it would have only hit glass, there would have been damage inside the truck. A direct hit on a person inside could have been fatal.
Many years ago, I used to give two young women a lift to our work in my three-door hatchback. The first one used to open the passenger door, lift the front seat, and sit in the back. One morning we were on the way to pick up the second, when a large spanner (wrench) came off a lorry (truck) about 20 metres in front. It came through the toughened windscreen and hit the front passenger headrest before dropping into the front footwell (after missing the dashboard). Glass was everywhere and there was a dent in the plastic headrest. If the second passenger had been in the seat, it would certainly have blinded, or perhaps, killed her. I was wearing sunglasses, and the back seat passenger had spectacles. The lorry was about 20 metres in front, and judging by the speed of the spanner, it may have been picked up between the lorry's twin rear tyres and ejected backwards. If it had just fallen from the back, its relative speed should have been close to mine, and may have caused less damage.
Could be that this wasn't an "air duster", but an actual air *cleaner*. ie, used to microabrasively remove contaminants from the surface of metalwork and polish it. Which, being a metalwork shop, is quite likely. And, being so, *will* have contained water and oil. The air is merely there to throw the water and oil at the surface of the metalwork to "scrap" off muck and give it a high shiney shiney.
I've done maintenance on air systems in many large industrial shops where there were several v8 engine sized compressors.
I've also maintained HVAC systems that used pneumatic controls (a lost art in many places)
They all had refrigeration based air dryers and purpose drain pipes with auto drains on them.
Water and air operated items do not get along well (especially in paint shops)
PS - I air blast my PC's with 100+ PSI air from my garage every spring and fall and have never had an issue as I keep my machines for well over a decade generally. I do run a drain on my tank every couple days when in use as I don't have a fancy air dryer.
Automotive shops usually use a basic water trap to catch water in the air lines, which is a glass tube at a low spot for the water to run into and a valve at the bottom to let the water out from time to time. They will only invest money in an air dryer setup when moisture in the line will cause problems, like a paint booth. Moisture in the air line when painting causes fisheyes, cloudy paint or streaks, and may cause rust bubbles over time if the water happens to hit first. Dryer setups are expensive to buy and maintain compared to the basic condensate catcher.
Back in my workshop days, part of the procedure on starting the compressor, was opening a bleed valve and letting the condensate spray out until it was no longer a visible jet.
Modern safety requirements have probably taken all the fun out of that..
Without that step, your air mix will be wet for a while longer.
On the other hand, there is only a limited amount of condensate present, as it is the dissolved atmospheric moisture squeezed out by the pressure, so by the time the guy had destroyed the first few PCs, the flow would be mostly dry
The problem with this (as notes) is that there is some friction in the spinner, and whatever ball bearings you HAD have gauled up the races. If you hav things like ball bearings that you have just soaked in solvent (to remove the old grease), and spin them "dry", you have just made a colossal paperweight as the bearing is totally borked. This happened to my dad's car in the 60's when some "brain" decided that it would be the proper thing to do when re-packing wheel bearings. New bearings later, the problem was solved. He had to show the service guy (a different shop) the noise while driving through he Broadway tunnel in San Francisco.
Of course on a worthless fidgit spinner, whose life is measured in hours of inattentiveness it probably doesn't make much difference.
In 2017 I used a workshop to spin up a fidget spinner. Got it up to quite a few thousand rpm, made an excellent noise. I eventually dropped it when it started getting hot...
In the second year apprentice mechanical workshop, the game was to take a ballrace, slip it on a screwdriver and spin it up using the airline. Then pull the screwdriver out letting the ballrace drop to the composition floor sending it screaming across the workshop and, if you were lucky, up the wall at the other end.
The other game was to grind the right angle part of a scriber off insert it in a closely fitting piece of brass tube, connected to the airline aim at the radar scanner 50 metres away and fire. I did wonder what the techs working on it though of all the scribers that they found there.
Where the gases really matter - say Anaesthesia or perhaps spacecraft* - labelling clearly won't stop misconn3ctions.
So incompatible fittings, of which the standard used to be pin-indexing, 6 positions around the orifice, with one or more pins in 1+ hole.
Now, if the hose wouldn't fit on the cylinder or machine and you were very confident, lazy, clever, or stupid, you might solve it by twisting a pin out with a grippy tool. But you'd have to work at it, as well as ignore instructions, training, future prospects oh, and safety. Guess what...
* Mark Watney found it convenient that NASA will have standardised propellant fittings so they could be interchanged, but that is several special cases.
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Back in the early 1950s TVs were the new domestic technology and few people had one. An aunt and uncle had one of the first in the area. My aunt looked in the back of it one day and found a lot of dust so she cleaned it out with the vacuum cleaner. They were given a loaner whilst it was under repair but it never got returned.
Custard powder explosion also has some great pictures around on the interwebs. Any number (well 1 or 2) people I know didn't believe me when I said "... flour and custard powder explode in the right conditions..." and lost eyebrows in their subsequent experiments.
icon cos any finely divided, combustible, material can be persuaded to get all exciting given the right encouragement.
Back in the day our high school science teacher memorably demonstrated this with a paint tin, a candle, I think a bike pump and some custard powder. Even for a small amount of powder it made one hell of a bang in a school science lab and the tin lid would clang off the roof. Now there was a teacher who knew how to teach :)
Take a five or six foot[0] length of 4 inch[0] PVC pipe. Drill four 3/4" holes around the circumference of one end, about 2" from that end. Place a votive or similar candle on the ground, and put the pipe over it. Light the candle through one of the holes. Dump a scant 1.5 tablespoons (10g) of sifted[1] flour into the open end. On a calm day, the minor explosion[2] can be fairly loud, and the resulting smoke-ring can rise & expand far more than you might think. All sizes are approximate. I've never actually measured anything when doing this, yet it always works despite my lack of care and attention. Do NOT do this indoors! If you do, the clean-up is a bitch. Don't say I didn't warn you.
NOTE! While I've never had an issue playing with this toy, nor have I ever heard of anybody getting hurt or doing damage to anything, this may be illegal in your jurisdiction. Most such toys tend to get lawmakers upset, probably because they are always vaguely afraid that somebody, somewhere, is having fun. Needless to say, children LOVE it ... and you can sneak a science lesson in without them noticing :-)
Yes, it works with coffee creamer etc. ... but again, you'll get best results if you sift it. Partially burned sugars in general make a sticky mess all over everything, so you might want to stick with plain old flour.
[0] Of course you know what feet and inches are. Don't be disingenuous, it's not becoming.
[1] If you don't pre-sift the flour, it might fall as a clump & extinguish the candle.
[2] Depending on pipe size, hole size & number, the grind of flour (cake flour vs AP, for example), the quantity of flour, how well it is dispersed, and other variations, the noise can range from a mild "pop" to a dull "thud" to a deep "bang". Experiment. That's what science is for, right?
Way back in the 1960s when school science teachers were allowed to get creative we made "flour cannons" as a lab project. The biggest bang got the most points. Knocking a ship in the plaster wall was extra credit. IIRC, a very small amount (like a teaspoon) of flour shaken well in an enclosed space was quite impressive.
Dust explosions can be really dangerous. I went to a flour-milling factory where people were employed full-time to carefully vacuum the walls and edges inside the building to prevent any collection of dust. The trouble is that a small, initial 'pop' can set up a shock-wave raising dust all around and creating a much larger dust/air combination.
The first number in the IP-ratings concerns dust-resistance for machinery and then areas are 'Zoned' according to the requirements of ATEX/IECEX. Designing machinery for use in those zones is a very detailed, expensive process. Electrical and electronic equipment are usually installed in separate, 'safe' areas. Preventing ignition of dusts and/or gases is a major industry; the potential liabilities are fearsome. Interesting though.
FOOF, or Dioxygen difluoride as it could be called, is wildly interesting, and not for the faint of heart!
An interesting read from a chemist with a sense of humour on some dangerous compounds - Things I won't work with: dioxygen difluoride
An excerpt:
And yes, what happens next is just what you think happens: you run a mixture of oxygen and fluorine through a 700-degree-heating block. "Oh, no you don't," is the common reaction of most chemists to that proposal
And if you go further down the rabbit hole, you find one of my favourite non-fiction books.
Ignition! An informal history of rocket propellants. https://www.amazon.com/Ignition-Informal-History-Liquid-Propellants-ebook/dp/B07D7M65M8
I wouldn´t read it while drinking tea near any important documents.
Ages ago I had done some installs in those areas at plants and coal mines and had to use explosion rated (essentially dust proof) cabinets and explosion proof the conduit.
The conduit we had to pack and seal at the joints to prevent dust migration in and spark migration out.
Motors used in those plants had to be explosion rated as well, usually TE (totally enclosed).
Dust explosions are freaky scary stuff.
Decades ago I went to a flour producers that still had some really historic kit housed in one of their buildings (think wood, not stainless steel)
Very few examples to be found - although some of that is due to old gear being junked when replaced instead of going to a museum - a big reason is that a lot of the old wooden kit burnt over the years - flour mills were (& still are) very dangerous places.
One of my abiding childhood memories is from the old QED programme that the BBC did.
There was an episode on testing, including exploding custard powder.
Prof Anthony Clare's narration somehow made it stick in my (warped) mind.
And yes, finding that link did take a nostalgic half an hour out of my day, now that you ask...
> explosive.
I live in the US Midwest, grain growing region. Grain dust is dangerous in grain storage elevators. They have to take steps to control static electricity and have to keep bearings from overheating. And probably keep too much dust from building up. Otherwise you get a big boom and you make the evening news.
I think they are doing better now as it seems to happen less now then when I was a kid.
Many years ago I had to take a physical chemistry course. The professor felt that we already knew enough, so he spent some of the time telling stories, to illustrate physical and chemical principles with real world examples.
One story is the difference between high explosive explosions versus space explosions.
High explosive explosions occur when a compact source, like a stick of TNT, ignites and expand outward very rapidly.
Space explosions occur when the contents in the air within an enclosed space ignite, and the entire airspace expand outwards very rapidly, blowing the building apart.
Space explosions can occur if there is, e.g., a gas leak in the room, or lots of dust, like in a grain silo
He told us how, during World War II, he invented a pen, that has a timer, a tiny explosive charge, plus a tiny butane lighter hidden in it.
The pen was covertly supplied to French partisans, to sabotage Nazi Germany facilitie..
The idea is for the partisans to get a pan of flour, set the timer, and bury the pen in the flour.
When the time is up, the explosion would loft flour dust throughout the room, like a warehouse.
The lighter then ignites the dust, to cause a space explosion, where the entire room is the explosive.
His story worked so well that none of us wanted to question if it is a true story.
WW2 did have plenty of such "madcap" tools for SOE and the various Resistances etc. Other examples include explosive disguised to look like coal to be dropped in locomotive tenders so it would be shovelled into the fire and explode, rat corpses packed with explosive so if they were disposed of in a furnace they would explode, also ones with explosive and a vibration detonator so if someone kicked the corpse it would explode etc. Not anything which would wreck a site or prevent production across an entire factory, but enough to cause annoyance, a few casualties, and more importantly, a sense of fear and mistrust in enemy command and troops, proving that resistance members were everywhere, and that nowhere and no objects were "safe".
It depends about the use of it. Normally even small air compressor have an air filter regulator with some oil. If the compressed air it's used for pneumatic control system, some oil it's needed to lubricate the valve. If one needs air without oil there are oil filter that block the oil.
Water on the other hand isn't a good thing on compressed ait, and there are water traps in filters for it, and of course one has to regulate the compressed air pressure used for different cases.
Whether the article is a true tale or not, I can attest to a similar tale.
Back in the late 1960s and early 1970s, when I worked in the American broadcast media, i.e., AM "Top 40" radio (ask your grandparents), at one station where I was employed the chief engineer would regularly pull gear out of the rack, chuck it into the back of his VW microbus, and take it to the local self-serve carwash, where he'd open up the cases, wash out all the accumulated crud with the pressure hose (including (ick) cigarette smoke residue), button it all up, take it all back to the station where he'd let it dry out in the sun, then pop it back in the rack, good as new.
Of course, this was back in the days of discrete transistors and vacuum tubes, so don't try this at home.
They just don't make gear. . . or chief engineers. . . like they used to.
In some print/packaging plants (even today) they use a AM frequency, as in a radio transmitter to weld the plastic packaging around the product. These packaging machines use very specialized tubes that needed cleaned every once in a while.
Some of these tubes contained radioactive elements in them that required very specialized handling and sometimes that standard wasn't maintained very well. https://www.amplitudemodulation.com.au/history.html#histtt
Can't remember the number of times I got called out because some dip-stick thought they new better than everyone else and managed to break the outter glass shielding of the tripple-shield and sending the machine into a shutdown-lockdown condition that required a crap load of work to restore.
There are people in this world that should not be allowed to operate anything with moving parts, let alone be put charge of a room full of machines with shit loads of said parts!.
I once worked somewhere where there was a major fire (~10 fire engines). The laptops in the affected part of the building really didn't like inhaling all the smoke and whatnot and were all sent away for specialist cleaning. We wondered why they weren't just replaced as the cleaning was expensive. I think all the cleaned computers died after a few months anyway...
I've told this before, but it bears repeating.
Magna Science Adventure Centre (or whatever it's called these days) in Rotherham has areas named after the four "elements". In the "fire" pavilion there is something called the Fire Tornado*. A Copper dish has 100ml of kerosene dosed on to it, is heated from below by 4kW for a minute or so (the kerosene has to start vapourising) several large fans are spun up and a spark ignites the kerosene, leading to what can only be described as, ahem, a tornado of fire, coiling its way up the flue in the ceiling.
As you know, while you can get "low smoke" kerosene, even the best of it, in barely-controlled burning situations, is emphatically not no smoke.
In the same room as the fire tornado? Half a dozen (maybe more, I can't remember), projectors (also plasma TVs etc), merrily sucking cooling air in from the room through some utterly inadequate filters, designed to trap office dust, not carbon-black. The first projectors began to fail after just a few months and opening them up revealed circuit boards and optical components covered in soot.
We (or, rather, a colleague) fabricated some sealed ducting with air piped in from a cleaner part of the building. I think the installers helped towards the costs, but frankly it should never have been built like that in the first place!
M.
*last time I looked it was still there, but it's over 20 years since I worked there and things do change. The Fire Tornado was one of my babies and required quite a lot of coaxing into life in the early days. It was affected by atmospheric conditions (the weather), quite apart from all the usual problems you'd expect
Sadly when we visited Magna some years ago it seemed to have been struck by the usual problem of such places, a lot of grant aid to set the place up but insufficient funding to keep it running properly. I hope it's changed but at the time a lot of the displays and experiments weren't working and/or badly needed maintenance.
It was a shame as the place was a great concept.
Lottery funding (Magna was largely Lottery-funded) is only ever for capital expenditure. Running costs have to be found somewhere else, and at Magna the first year was good until they decided to increase the prices to the sorts of levels Merlin Entertainment would appreciate. Thing they forgot was that Magna - being in Rotherham which is hardly a place people choose to go to on holiday - had a very high proportion of repeat local visitors. Grandparents with grandchildren on INSET, for example. Putting the price of a season ticket up from the equivalent of two and a half normal tickets to the equivalent of four or five* severely affected these visitors, but the money to keep the place going had to be found from somewhere; and it was quite expensive to keep running for various reasons that were at least partly down to poor design decisions.
And once the visionaries who saw the project through to opening had left for pastures new, the remaining managers were a bit more hard-headed and - and I'm happy to say it at this distance - petty and vindictive. I was pushed out for totally spurious reasons, having questioned the direction the business was taking and a colleague left at the same time for similar reasons. A year after I left, from what I could tell there were only three people in the whole organisation who had been there more than a year.
M.
*it was something like that. I can't remember the specifics at this distance!
Techniquest in Cardiff, which might well be the original "science adventure centre" (current building is their third) has had a rough time in recent years but seems to be going ok at the moment.
Techniquest supplied one exhibit to Magna. When Techniquest started they had to build almost everything themselves and they started supplying exhibits to other places. Since then dozens, if not hundreds of other companies have sprung up to fill that space and Techniquest's development department was closed maybe 15 years ago. This year they are hoping to re-open it.
M.
Might want to look into San Francisco's Exploritorum before you make that "the original" claim again.
https://en.wikipedia.org/wiki/Exploratorium
Opened by Frank Oppenheimer[0] in 1969, and still going strong.
This is probably the only reason I see for visiting San Francisco at the moment. Highly Recommended.
[0] Younger brother of Robert.
"I wouldn't like to even place, let alone open a PC up in any metal-working environment."
That reminds me of the time I was sent to assess and repair a PC in an iron foundry. It was full of black dust. Half the DIP chips had crept out of the sockets. I swear it was only the iron content of the dust that had kept it mostly running!
It is surprising what a PC can put up with inside. Opened a PC controlling a CNC milling machine once... to find black oil had misted in. A nice old mess in there.
One of the best was paving slab manufacturing in an old barn. Even though the office was the other side of the building in a separate room, each horizontal surface was covered with half inch of fine cement dust. Piled up on each of the add-in cards. And as this was Pentium era, that was a lot of extra cards to pile the dust on. Hate to think how much of that had got into the hard disk. Or staff lungs. Could have done with an airline that day.
When I use airlines, I always blast the desk with them first to check power and water content. And remember to jam screwdrivers in the fans to stop them spinning and cover the HDD breathe hole. When used right airlines work well in industrial places - especially now we have SSD so no more dust in drives.
One of my clients was a polymer compounder, lots of nasty particles, tungsten was a good one - really fine particles and uber abrasive. There was a requirement to put a PC on the shop floor so we were coming up with a spec for the required enclosure, IP66 or IP67. Speaking to various potential suppliers one said "That's higher than a Main Battle Tank!" - not sure if that was true, but I certainly felt like I had my big boy pants on!
Speaking to various potential suppliers one said "That's higher than a Main Battle Tank!"
Back in the old days, the British Army's Challenger MBT serving in the UK and Germany was notorious for appalling reliability. Come the first Gulf War and it had fantastic performance, which was put down to the dryer environment, so perhaps they should have specified IP67 (or made it effective). Maybe it was IP67, but that wasn't enough - I'm sure there's somebody round here will know in more detail?
Yeah, it was mid-90s, so Challenger 1. I didn't check with the vendor, as we knew what we wanted, and it was obvious that was beyond a limit for them. Rather than a PC in an enclosure (wouldn't have lived 5 minutes) deployed a dedicated IP rated PC - awesome kit, well for the time to track it down. I'd have to dig the paperwork out for the manufacturer, a quick search doesn't reveal. Virtually totally sealed - mainly stainless steel. External KBD would just die, so the integrated touch screen was covered with layers of transparent, what, Kevlar(?! lol) that could handle the grief and be peeled off by the operators when they got a bit sloppy.
I think that may well be more down to maintenance than anything else - if you're just in steady state peacetime ops with either no hope of stopping the Russians if they do come through the Fulda Gap or at home then costs can be cut on maintenance, but if you KNOW you're deploying to a hot environment with likely use of chemical weapons and missiles then you make absolutely sure that your tank is in tip top condition with all the bits working and all the rubber seals in place and not perished etc.
I need more coffee this morning it seems. It took me far too long to realize that when you said "jam screwdrivers in the fans to stop them spinning" you meant while the computer was off, so that the compressed air doesn't spin them, and not while the fans are actively running.
I once got a PC in for repair from a guy who carved gravestones.
Sensible guy, he realised the computer wouldn't like the dust, so he sealed up every hole in the case.
I'm surprised it lasted as long as it did before things started to burn out.
Needed a new motherboard and case and worked fine afterwards. When he got it back, he moved PC into the next room and ran the monitor, keyboard and mouse cables through a hole in the wall...
Holiday resort on the south coast of Tenerife back in the 1990s. We had our large Dell network server in an office with no windows and a door which was locked most of the time at the back of the resort reception which was open 24 hours. Every 6 months we had to get our local IT support to come and vacuum about 1/2 inch of really fine sand from the bottom of the machine. The sandstorms that came across from Africa were so bad we had to repaint the outside of the resort every 3-4 years because the sandstorms would strip the masonary paint off the concrete.
Went to a client who had a small PC just for downloading to the CNC machines which they said had failed (after about 4 years). It was in a little office space with the door propped open and a whole bunch of grinding machines nearby. Basically the inside was all covered with a thick layer of metal dust. I was impressed that it had kept working at all. Sure, you could get one with an IP67 case, but it was cheaper to just replace them when they failed.
At around the same time, I was the engineering buyer for a factory that produced various liquid and powdered products. Occasionally, we'd have visits from prospective customers, who came in for a tour of our state of the art, automated production facilities.
Naturally, some of the production areas could get quite dirty, so the customer visits were always proceeded by a big clean up around the factory. One such day, a recently employed production assistant was tasked with cleaning up the office areas, including the process control booths.
Noticing the state of many of the keyboards attached to the various DEC VT100 terminals (I did say it was MANY years ago), she decided they'd all benefit from a good scrub and proceeded to do just that in the sink in the factory break room.
A couple of frantic phone calls, and several called in favours later, we had a taxi full of replacement keyboards on the way from the local DEC distribution centre. I forget the final bill for the episode, but it was well into four figures, not counting lost production time.
Given the price of VT keyboards I'm not surprised the bill was high, however from experience they could survive a scrub sometimes.
We had a keyboard that had been Tangoed so with little left to lose we disassembled it and gave everything a good scrub under warm running water. After leaving it all to dry thoroughly (which was possibly the key) and reassembling it we found it worked perfectly.
That DEC kit was fairly bomb proof, I'd left a VT220 in the computer room which then suffered a catastrophic fire due to an electrical fault in the room next door. The terminal case was heavily distorted and melted but just for the crack we did try plugging it in. The screen was a bit dim but duly came up, "VT220 OK"!
"bomb proof" is an interesting choice of words...
We had an office in Belfast with many VT200-series terminals. A car bomb left outside the front door blew in all the windows. When the staff were allowed back in they found all the terminals still on, still displaying whatever work had been in progress when the evacuation was ordered, but not a single keyboard still worked. No smashed screens, though, even among those chipped by flying glass.
I once gor a frantic call from a friend who was wriring a book on the family's Fat Mac while her baby sat in her lap.
Her: "Help! Andrea just spilled orange juice into the keyboard and it won't work!"
Me: "Is your computer under warranty?"
Her: "No. It's too old."
Me: "Fine. Fill your bathtub about eight inches deep with cool water, letting the water from the faucet run through the keys. When you're done adding water to the tub, put the keyboard in, swoosh it around gently, and let it soak for four hours. Then, take it out, let it drain into the tub, and put it somewhere safe for three days to finish drying out. After that, plug it in and see if it works."
Her: "But that might ruin it!"
Me: "It's already broken, and there's no warranty left to void. If this works, then great. If it doesn't work, you haven't lost anything. Right?"
Her: "Yeahhhhh ..."
Three days later, my phone rings.
Me: "Hello?"
Her: "It works! Thank you!"
Many years back I accidentally poured coffee into the keyboard of a very expensive Cadnetix workstation. Fortunately my wife knew a lot about materials including substances that dissolved other substances. Just take it apart, wash it under a warm tap and then leave it to dry over the weekend, she said. Worked a treat.
I use my leaf blower to clean my PC's every couple of years, but not from too close as it's a powerful tool and fans will spin rather fast when the air hits them.
I have been doing it for decades and it's never done damage though, the first time I ever did it (back in the 90's) I did blow the PC over. Fortunately no harm was done and subsequently I have supported the PC properly. I always run the leaf blower for a little bit first and give it a shake to ensure it is free from bits so nothing but air is going to hit the PC.
A leaf blower is definitely not an inside tool so I use it on the patio where it's very satisfying to see the big cloud of dust instantly emitted from the PC. GPU heatsinks do seem to be dust magnets but nothing large volumes of high speed air can't fix
.......YMMV
This post has been deleted by its author
At least that's a valid use for a leaf blower, which brings us back to the suck/blow debate mentioned earlier.
I've used a leaf vac for years, it sucks up the fallen leaves, I bag them up and dispose of them. All a blower would do is to spread them onto the street or neighbours' property, that would make me really unpopular around here.
It's a matter of scale. For a small garden using it to suck is appropriate. For a big garden that would take forever. I have a very big garden. I use my blower to push them out of flower beds and move them into a manageable heap where I pick them up by the armfull and put them into 0.6m^3 bulk bags .... several of them. In the back garden its easier. I use the blower just to move them away from the edges then sweep them all up with my ride on lawn mower.
A leaf blower is definitely not an inside tool? Nonsense, I use a leaf blower to blow out he cottonwood fluff our of one window screen, the screen was in place when the window blinds were installed, to remove the screen for normal cleaning requires removing the blinds... BrmmmBrrr!
Compressed air can be very dangerous to human health. There is a fairly well known case of apprentices who, for a prank, fired a blast from an airline at a lad who was up a ladder with his, er, back towards them. He died at once from intestinal shock. Another thing I would not do is use an airline to clean under my fingernails, due to the danger of embolism, in fact I would take care not to spray myself full stop.
Compressed air has all manner of dangers, some less obvious that others. As a poor student many decades ago I once did a summer holiday job at a company that made and rented wooden pallets used to stack goods for movement by forklifts. My work was out in the yard unloading articulated truckloads of pallets and inspecting them, but in the construction/repair shed, the permanent staff used air line nail guns to instantly drive a 4 inch annular nail into wood (not your lightweight brads, proper meaty blighters). The nail guns used collated strip feed nails, and had a safety collar to stop them firing unless against the wood. Once in a while, one of the none-too-bright employees would take it into their head to hold back the safety collar, and fire off a strip of nails like bullets down the 70m+ length of the shed, with a fire rate I'd guess of several hundred per minute. Remarkable how quickly the slothful can move when they hear the rat-a-tat-tat-tat and the ping of ricochets.
Similar principle applied when back in the mists of time I worked at the fabled Ricardo Engineering at Shoreham, development engineers of the highest order.
This was the 70s but the Chinese lorry engines on the brake dynamometer were designed in the 40s and running at full load and peak revs the exhaust was glowing cherry red. Lesson 1, do not stand at the side of the engine, stand in line with it so you aren't collateral damage if things go bang.
Someone had one hell of a near miss when a top radiator hose ruptured though - superheated water ejected under pressure in a confined space sounds very very nasty.
> a patched hole in the ceiling
Above my head here is a framed hole in the plasterboard. I was on my riding mower 30 meters in front of the house when Zing! Crash! it threw a rock through the window. I taped a cover over the shattered glass, but where was the rock? We finally spotted the dent in the wall, and hung a picture frame over it.
100psi/7bar shop air for a few seconds will NOT kill PC fans, small or large. They can exceed 10,000rpm for many minutes, longer than you can stand the noise. With luck that will break-down the fish-oil in the sleeve bearings so you can re-oil. I have never lost a fan this way; they often serve for years. (I;m a cheap SOB and won't replace a fan if I can avoid it.)
I had a diaphragm air pump once, it was heaven not having oil in the exhaust. Piston air pumps MUST have oil in crankcase and inevitably in exhaust. Breathing this slightly oiled air, as a diver, will give pneumonia, probably fatal cuz if you knew what you were doing you wouldn't do it.
I really doubt he "blew the chips out of sockets". Has anybody tried to do that?
> a patched hole in the ceiling
At an place where I did my apprenticeship in the machine shop there was a hole in the roof above a machine, this machine had a hydraulic piston that did some function or other (I can't remember what) pointing upwards and at some point whatever it was pushing up against was suddenly not there.
The piston ejected up through the roof and landed on the main road outside, thankfully traffic was light in those days (late 1970's) and no vehicle was hit by it.
It made a hell of a bang when it went I was told.
When I started work (1969) in the training school in an infamous works in Beeston Notts England (UK Europe The World, as any fule kno)
I was shown the spring-loaded safety chuck-key.
This had been invented in, and patented by, the company, but had never been produced commercially.
Dunno if it was ever taken up after the patent expired, but it shows the attitude to safety in those days.
Hence the failure of the naval experiment to use ultra high pressure compressed air. Microscopic leaks proved almost impossible to prevent, & were ultrasonic. That wouldn't have mattered if those leaks hadn't also functioned as a highly effective scalpel on any meat-based material that came within range. Imagine walking down a service duct & your arm just falls off...
Otherwise, in 25 odd years in the car trade I never encountered an in-line dryer on a compressed air line except in body & paint workshops. Even in line oilers were rare as it precluded use of compressed air for "drying" cleaned metal parts. The best equipped workshops (so newer dealership 'shops in practice) had oiled & oil-free outlets at each bench. Everyone else just dribbled a few drops of oil into their air tool's inlet periodically, which was perfectly adequate.
It's been a few years, so the details are blurred, but a mate of mine once told me one of the more valuable tools in the engine room of a steam-powered ship is several good, solid broom handles. That way there is always something conveniently nearby to wave around looking for the source of steam leaks, rather than a hand or arm, which could mean almost instant amputation under the right conditions.
Another grisly rabbit hole to go down: high-pressure injection injuries
I worked at a place that used compressed air to run nail guns, staple guns, and air guns. The last are used for "blowing things off".
The company was very safety-minded, yet we never were warned against using air guns on ourselves -- not verbally, not in any of the safety videos we watched, and not in any documents.
Two relevant factors here:
(1) What pressure your air lines are running at, and,
(2) How much the air guns reduce the airstream pressure.
I used to use the air guns on myself all the time. It's nice to stick the gun down the back of your shirt on a hot sumner day and cool off.
Your mileage will vary.
> he blew memory chips and any other loose bits completely out of the motherboards."
Obligatory Italian Job quote
In my first job was in a college, my immediate predecessor was someone who believed that WD40 could fix anything... including computers. However it turns out that soaking the motherboard in WD40 does not - in fact - fix computers but he still persevered with his attempts until they got rid of him.
Also in that job, we had labs and labs of Amstrad PCs which had a light grey finish that really picked up the dirt from the rather grubby students. We didn't like these computers much, so we cleaned with with a bucket of warm water and some washing up liquid once a year. They were annoyingly resilient to this cleaning process and ended up looking sparkling.
The other problem was mouse balls.. we had to glue the belly doors close to stop the students removing the balls. However, the rollers would still clog up with body grease and skin particles (yummy) so the mice needed to be disassembled to be cleaned properly. This involved removing all the screws on the bottom, which of course would often go missing and then giving the rollers a good scrape. Thank goodness for optical mice these days..
> ...disassembled to be cleaned properly.
I used to do that as preference, as access to the rollers was usually way better.
> ... screws... which of course would often go missing
Ah ha! That's where you need Pickle Rick's patented Handy Receptacle! You get some handy container, often a WD40 cap, and put all the screws in there. Then, just as you've finished cleaning the rollers, you can spend a few minutes picking up screws after knocking the Handy Container off the desk with your errant elbow! (Seriously, I've done that so many times, I started putting the Handy Receptacle on the floor. I still manage to kick it over, but the screws don't travel so far!)
I've just bled the air from my central heating boiler, and of course as I put the cover back on, one of the screws pingfukkit'd down the little hole in the counter top the pipes disappear into.
Of course, being A Man, I had plenty of jam jars to rummage through to find a suitable replacement. ;)
I’ve learnt before starting such jobs to: put the plug in wash basins etc. to put sheet down covering such gaps, because you can be sure on reassembly one or more screws will either fall off the end of the screwdriver (magnetic or not) or fingers-and-thumbs fail to properly place screw in correct location.
We used to say ashtrays were a labour-saving invention - instead of dropping cigarette ash all over the floor, we'd collect it in a dish so we could drop it all on the floor in one go.
Re screws, magnetic trays seem like the kind of crap your mother in law buys you for Christmas, but are in fact surprisingly useful.
"screws ...vwhich of course would often go missing"
Car parts suppliers have handy bowls with a magnetic base. That holds them in place on a vehicle and I think also holds the small parts inside them. And iFixit have a magnetic mat. You can write on that with dry erase markers, so some of those screws might even go back in the right place.
Gosh, is it that time of the week again? -->
>” However, the rollers would still clog up with body grease and skin particles (yummy) so the mice needed to be disassembled to be cleaned properly.”
Remember in the days of COVID having to deep clean mice and keyboards as part of a regular deep clean for a client. Remember discovering that some manufacturers (HP I seem to remember) did make some of their keyboards easy to disassemble and clean in the dishwasher.
I can't recommend the unchewed lid from an old-style Bic pen (tapered round profile, not squared-off} highly enough for this - just the right amount of sharp edge, just the right amount of flexibility, just the right length of both handle and blade for my pudgy fingers.
The other problem was mouse balls.. we had to glue the belly doors close to stop the students removing the balls. However, the rollers would still clog up with body grease and skin particles (yummy)
If you think that yucky, try servicing the card readers on ATMs clogged with a grey greasy substance from peoples pockets transfered on their cards. We used to use Freon by the pint until it was banned.
laptops died of compressed air.
The thing got hot and the numpty saw that the CPU fan wasn't running (yeah we know where this is going), so numpty got the airline... and used it on the fan to get it spinning
We think it structually failed at 25 000 rpm. although numpty said it was still accelerating..........
Oh and open the case to get rid of metal chips that had gone in the back..... airline for that too and another one bites the dust.
I've got quite expert at taking the HDD out and recovering the data
I've never had any issues with fans - whether on PSUs or processors - that people are mentioning here. Always hold the gun at a sensible distance - particularly for keyboards as caps will just fly off - and enjoy the wheeeee as the fan spins faster than it's used to. Never seen one die afterwards and I've seen some oooold PCs in workshops.
I did used to work in a window manufacturer and the amount of swarf that comes off PVC profile is insane. PCs literally embedded in piles of it within machine enclosures after a few week, with so much that you have to shovel it out before you bring the airline into play. At least it's nice and clean, but you'll never worry about the microplastics in your drinking straw again.
Had an old boss a long time ago that decided to clean the paper dust out of our early laser printer with a vacuum and the small nozzle. Unfortunately didn’t notice the high voltage wire that charged the drum and snapped it in two. Don’t think we could get a replacement for that part either.
Surprised no one has mentioned the fact that compressed air can generate static electricity, and we all know that's not good for semiconductors. The use of compressed air for cleaning products was verboten in at least two consumer electronics manufacturers I've worked for. De-ionised air curtains - yes, compressed air - no.
I'm the anon above who "jams a screwdriver in the fan". The reason I am doing this is not due to fan failing, I just don't want to turn the fan into a little generator and push current into the board while I am cleaning it. Run a fan motor backwards and you have a generator. Now I don't know how much current this makes, but I don't want to find out.
A guy systematically blows apart 5 workstations in a row, and it’s an “accident.”
We call that one “deliberate sabotage,” or else “fictional story.”
I had a coworker at one place of business who was trying desperately to get fired, I think his motivation was he wanted some free time on Pogey (“unemployment insurance.”)
He told the boss he developed mental problems and was no longer able to work, and he still got reassigned to alternate duties(!)
My fellow engineer… he had a pretty cool Robotech model kit collection though.
One of my former colleagues was a world leader in his subject, with multiple awards and honours. No one would doubt that he is a very bright guy indeed! But he was renowned for destroying equipment, sometimes quite dramatically!
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