dust in electronics: how to remove?

[Islander]

This is not your regular household dust. Last week a worker was grinding smooth the concrete on my balcony deck. A week earlier, the livingroom and bedroom sliding doors had been removed and replaced with plywood in preparation for replacing them with modern units, after all the prep is done on the openings.

The thing is, there are lots of air gaps around the plywood. I was at the computer at the other end of the apartment and heard the grinder start. After half an hour or so, I decided to take a look and found the air in the livingroom and master bedroom fogged with cement dust. I got the worker to stop right away, until all the gaps could be taped up, but there was dust all over the furniture, on the bedspread and pillows, on the sound system, and on everything else in the place.

I vacuumed the TVs, the speakers, the furniture, the carpets, and dusted where I could, but what about the dust in the receiver and power amps?

A light duster got the worst of it, and a damp cloth will clean away what I can see, but there must be a fair bit of concrete dust that's fallen into the cooling vents. What about using the vacuum cleaner to try to suck out the dust that fell in? Supposedly it's a bad idea to vacuum computers, because a static charge can be generated that will damage their components. There are a lot of similar parts in amplifiers, so would it be a bad idea to bring the upholstery brush nozzle near the amps?

I'd really like to get the dust cleaned out, but I don't want to cause any damage, and I'd prefer not to open the housings. Does anyone have any successful experience with an issue like this, or is opening the housings and blowing out the dust with compressed air the only way to go?

[tigerwoodKhorns]

Electronics suply houses sell cans of compressed air. Even though you don't want to, take the covers off and blow them out.

[Islander]

Well, that's good to hear, although I was told it by someone who knows more about computers than me. Using the vacuum would sure be a lot simpler. The receiver housing is mostly open, so it should be easy to chase all the dust out, but the Class D power amps have only a few small slots on the top. I don't want to blow some dust that's just in one spot right now all through the amps.

Thanks, Mark!

[Saturn5]

Vacuuming is fine, but you don't want to use a hand held, etc. There's a danger of static damage to the electronics, but that's primarily associated with the vacuum cleaner motor. If you have an attachement on a hose, you're fine. We have a special vacuum at work designed specifically for computers and electronics. It's basically a portable canister vac with special filtering, etc. (printer toner dust is too fine for regular vacuums to pick up - it blows right through the bag)

Canned air is also good. If it's really bad, you'll need to open them up to clean it out properly.

[DrWho]

Most vacuum hoses have plastic tips....friction on a plastic surface
is a great way to build up charge and then it's certainly plausible
that you could get an ESD event to happen inside the electronics you're
working on. It's more of an issue for devices using MOSFETs because the
gate oxide is very thin and it doesn't take much to punch a hole
through it (rendering it useless).

I have
vacuumed inside all sorts of electronics without any problem, but
that's not to say that it could never happen. As long as you discharge
yourself to the chassis and then touch the chassis while holding the
plastic nozzle, then you should be fine. Basically, you'll be shorting
out any charge that builds up. The stuff flowing through the nozzle
shouldn't really be creating enough friction anyway, but you never
know. I can think of a few times where I've had the hairs on my arms get
attracted to the charge buildup on vacuum nozzles before - I don't ever recall getting a zap though.

Compressed air might work better anyway because it's easy to get the
straw down into the little nooks and crannies. Just make sure you don't
let condensation build up when spraying.

[Islander]

I'd be using the brush nozzle rather than the hose itself, in order to avoid any scratches, plus have one hand on the housing, so it sounds fairly safe. I might as well just cover the amps until all the grinding is done in a day or two, then disconnect them and slide them out of the audio stand and clean them properly.

The compressed air may be all that's needed for the receiver, because I can see into it fairly well, but the amps are almost completely closed up, except for the small cooling vents on the top and bottom, so I'll take a close look with a flashlight before and after vacuuming. These amps cost more than many of the used cars I've owned, so I want to do it right.

Half an hour of dust entering the apartment has caused me hours of work to clean up. I sat down to watch TV and even the TV Week magazine was dirty and gritty. I guess I shouldn't complain too much, though. It's not like I had a hurricane come through. Have you seen what's going on in Manitoba and North Dakota? They've got flooding and freezing, so a lot of folks may have their houses and cars totally ruined. Hopefully there won't be any injuries as well.

[JJkizak]

If the static discharges worry you then you may employ the methods used in a state of the art chemical plant.

1.....Full metal screeening embedded in all the concrete floors with 3/4" cable/wires fastened from the screening to all of the structural metal support beams.

2....Plant vaccum system all metal with metal hose ends with explosion proof fittings and trace ground wires on the entire system

3....All relays and contactors remoted to an electrical room

4.....All motors explosion proof and sealed.

5.....All pushbutton controls explosion proof

6.....All control panels explosion proof

7.....All 120volt plug/outlets explosion proof

8....All extension cords with explosion proof connectors

9....All 480 vac welding outlets explosion proof

10...All air compressor piping iron and welded fittings and ground wires.

11...All other piping used in the manufacturing cycle stainless tig welded with grounds.

12...Hot oil piping used for heating mixing ovens (600F) iron with temperature control hangers and heat insulation.

13...All electrical conduit threaded galvanized.

14...All tow motors fully electrical, no natural gas.

15...All scrubber items fibreglass or schedule 80 plastic CPVC including the fibreglass pumps.

16...Nitrogen blanket on all manufacturing processes

17...Water explosive balls on piping systems to prevent explosions

18...All ventilation systems explosion proof.

19...One of the walls in the building constructed so it will blow outward easily with an explosion.

20...Fire alarm system that controls sprinklers fed with foam and will alarm when any major valve is operated by mistake. Sprinkler water from huge lake

with filter to remove Canadian Goose crap.

21...Automatic refill of the waterlake with 12" water main. (toilet bowl float on humongous valve)

22...Computer control room cement blocked in to prevent dust with auto closing metal door.

23...Precision measuring equipment the average person cannot comprehend (temperature control +- .1 degree F for entire 600 F degree spectrum)

24...There is more but I'm, getting tired.

JJK

[Guest " "]

Keeping relative humidity above 40 %

[Islander]

Keeping relative humidity above 40 %

I'm glad you mentioned that. The livingroom humidity is around 42% right now, but it went as low as 20% at certain times during the winter.


As for the workplace that JJK described, I'm not sure I'd want to work in a place that dangerous, although I did work in a powerplant with eight 300-megawatt hydrogen-cooled electric generators, powered by turbines driven by 2250psi of dry steam at 1000 degrees C. The turbine room alone was eight storeys high and 400m (1/4 mile) long, so the building was pretty big.

People worked carefully and there were a lot of safety procedures in place, but if something major had gone wrong, many workers would not have made it home, to put it delicately.

[jheis]

I've used a vacuum cleaner on many computers and all kinds of electronic gear w/o any problems. A half inch paint brush works great for getting dust out of the nooks & crannies as you suck it up with the vacuum.

James

[Marvel]

We use a vac made for computers, but a lot of times, the stuff just sticks too well. Even though we have a smoke free environment, it just doesn't get the job done. I usually pull out the air compressor, and roll everything outside. We don't even bother with a water trap, but have never had any trouble getting the dust out of pc chassis. The air will get dust out that a vacuum just won't touch.

You won't want to leave the concrete dust on them for long, as the reaction with high humidity probably won't be very good for the metals.

Bruce

[JJkizak]

A long, long time ago in "tooooby land" we used to spray (small air compressor) the entire chassis with tri-clo (like brake cleaner) and all this black dirt would flow onto the floor. After 15 minutes of breathing the fumes we were pretty high. Things got cleaner than camel snot on a doorknob. Most of the dirt was from the filter gunk that was supposed to catch the dust. Didn't work. All of our big rectifiers and transformers were filled with bi-phenols (Pyranol) which we had to clean up because everything leaked. I'm surprised to be still alive.

JJK

[Marvel]

You can get spray cans of chem-wash. Works pretty well... just be careful of the plastics, as they can turn some clear pieces white or foggy.

[fini]

Corn brooms are good for any concrete chunks in there.

[slumberer]

To really clean electronics, opening them up and using 90% alcohol (as opposed to 70% medical rubbing alcohol) with an acid brush is the best way. Saturate the boards, lightly brush all the grime away until the solder is bright and allow a few hours to dry. If you cut the bristles of the acid brush in half, it will clean stubborn spots easier. You don't have to worry about alcohol damaging anything as long as you allow it to dry completely (the 90% will evaporate very fast). I have resurrected many a circuit board just by cleaning in the above manner and reflowing any cold solder joints. It might be awkward to wipe up the removed dirt unless you remove the boards from the components, but if any of your valuable gear starts malfunctioning, a good cleaning is worth a try before throwing it away. Obviously this must be done with power removed including any batteries on the boards, and may be more than you want to do unless you have a problem with gear that is out of warranty. Just giving an electronics tech's input.

[Islander]

Thanks for all the tips, guys! There was a lot of helpful stuff in there. The idea of using a soft brush and the vacuum at the same time sounds like a particularly good idea, while using alcohol would have to wait until the components are disassembled.

As for using trichloroethylene (TCE) or perchloroethylene, there are a lot of safer products out now. Those powerful degreasers made a lot of people sick and should really be avoided.

[Islander]

Finally got time to disconnect the amps and pull them out of the rack. Luckily, it looked like not much dust got inside, but the outer parts of the tops looked like they'd been sitting in a body shop for a while.

I vacuumed them with the upholstery brush, making sure my other hand was on the amp to avoid any static build-up, as suggested, then wiped them with a cloth sprayed with Pledge Multi Surface. The label indicates it's good for electronics, metal, wood and glass, so I picked some up to try.

The amps have thick aluminum edging with a black piano finish, and I was pleased to see that they cleaned up like new. No problems, and they're sounding great as I type this. I'll probably cover them up when they're not playing, until the construction is finished.

[jbsl]

try what these guys use. []

[Deang]

Remove the top, and take it outside..

Plug in your leafblower.

Stand a few feet away and let her rip.

I know it sounds crazy, but you'd be amazed at how well it works.