attack of the dustbunnies

[zandrax]

Re: attack of the dustbunnies

zandrax
I used to work on gear for Nuclear plants.
Approved methods there: (some)
A brush. NOT plastic/nylon bristles. Had to be horse or hog hair. (Yeah, sounds funny)

Not so funny: plastic can be charged and you should avoid any electrostatic spark. This is a judicious suggetion.

Vacuum (Approved models were specified.)

A 20+ years old vacuum, Vorwerk brand - the one I have.

Compressed air set to 30 psi max.
(We'd cheat and crank it up to around 60 cause 30 don't do much.)

Hmmm ... I can try this option when I'll afford a decent compressor.
BTW, can compressors ionize the air they blow?

Isopropyl alcohol (90+%) (with a horse hair acid brush if needed for scrubbing PCB)

Good cleaner and deoxidizer.

Most of the other options release things into the environment and are illegal now.
Before that we used to use TriChlorol-something-or-another fairly often.

Acetone to remove stickers glue and termal compounds: only in open air because it's toxic. Beware: it melts most plastics and remove some pcb coating layers, so don't use on ICs and on any board.

We would get 91% Isopropyl in 5 gallon cans so if something got drenched (there's water and steam pipes all over in a power plant) we could literally wash the boards in alcohol to dry out the water. (It works.)

Thanks for the tip.

I don't like compressed air on laptops unless I have them completely opened up.
It can shove dust bunnies into tight spots inside and make matters worse.

I did actually open the notebooks I cleaned (already out of warranty): I could clean their heatpipes only by blowing air inside them, clouds of dust came off untill I could see some light through them. Computers became a lot less noisy after the cleaning

Zandrax

[willawake]

Re: attack of the dustbunnies

Acetone to remove stickers glue

something like cramolin labeloff is better and not melting plastics. citrus based.

[zandrax]

Re: attack of the dustbunnies

something like cramolin labeloff is better and not melting plastics. citrus based.

Thank you: I found the Label Off on the Itw site.

Zandrax

[PCBONEZ]

Re: attack of the dustbunnies

As to: Ionization in compressed air:

Never heard of that being a problem.

I've painted cars, sand blasted, worked with air powered motors and cylinder.
Never seen anything to indicate static on compressed air.
I suppose if you were using some air hose made out of some unusual material it might be an issue, but Ive never seem or heard of it.
-
A bigger problem with air is making sure there is no oil in it.
Usually a problem with old or cheap compressors that leak oil past the rings.
Also if the air hoses were ever used on an air mister for oiling air tools.
-
I use a micro-filter type trap to catch any oil in the air. Also have a designated 'clean hose' that is another color from the hoses I connect to the mister and air tools.
(Also use that one for painting cars, don't want oil in the line then either.)

.

[PCBONEZ]

Re: attack of the dustbunnies

Isopropyl actually works pretty good for 'most' sticker goo too.
Takes off wax pencil marks very well.
If you work it a little with a tooth brush it will get some kinds of magic marker and ink pen ink off.

.

[Spacedye69]

Re: attack of the dustbunnies

Yes ionization in compressed air is a consideration. I worked at a company that did vacuum coatings for the aerospace industry and and a customer that made sattelites came in and brought their own "anti static, deionizing" air nozzles. I don't think consumer electronics are up there with the Space Shuttle, many people use compressed air to blow dust. This customer was a freak. They would also measure coatings that were microns thick with a micrometer!

[PCBONEZ]

Re: attack of the dustbunnies

They would also measure coatings that were microns thick with a micrometer!

I've had to do that.

What's even more fun is trying to measure surface roughness.

We also had a couple of Faro Arms which has to be the coolest tool I've ever seen.

http://www.faro.com/contentv2.aspx?c...tem=1018&ct=us

It can measure the X,Y,Z axis of anything within 8 feet to +/-.0007 inch.
It feeds the data into a CAD program in a laptop and creates a picture.
If you wanted to you (and had a LONG time) could touch a car all over and make an EXACT 3D drawing of it on the computer.
- You would even be able to zoom in and see a chip in your paint.

....

[acstech]

Re: attack of the dustbunnies

Before that we used to use TriChlorol-something-or-another fairly often.

It wasn't Trichloroethylene was it? That stuff can be hazardous to your health! It's also used in brake cleaner, although it has been recently replaced with perchloroethylene. Still something I want to avoid. However, I do use it sparingly to clean off heatsinks and processors before applying thermal compound. It absorbs heatsink compound like a magnet and leaves no residue. You just have to be really careful with it, and put the rag ouside when done.

[PCBONEZ]

Re: attack of the dustbunnies

I hate spelling those so I skipped it and I'm not gonna spell check.
And, ah, as I already said we stopped using it because it was hazardous.
There were several:

Trichloroethylene
Trichlorotrifloroethylene
Trichlorotriethylene

There were like a dozen approved for inside NUC plants back then.
Considering where I worked that was a pretty small hazardous compared to some of the other hazardous's we had going on.

.

[PCBONEZ]

Re: attack of the dustbunnies

There is one of them (or out of the same family) that is still used inside the high pressure oxygen systems on submarines. It's used to remove every trace of hydrocarbons from inside the system after it's closed up. Even the oil in a finger print is to many hydrocarbon present when you press-up oxygen to 3000 or 4000 psi. There have been a few cases where hydrocarbons got missed and the Stainless Steel pipes (on the oxygen side) caught fire. (Yes, in 3000 psi O2 even SS will burn.)

They have come up with an alternate chemical and procedure that doesn't harm the ozone but it's MORE hazardous to people handling the stuff than the old stuff was.

.

[PCBONEZ]

Re: attack of the dustbunnies

This stuff "NOC"
http://p2library.nfesc.navy.mil/P2_O...k/3_V_B_4.html

They make is sound all safe in the DOC.
They leave out the fact that to use it: Temps 120f to 170F with agitation...
And that the non-liquid parts human body are mostly hydrocarbons.
This stuff is so nasty against hydrocarbons that if it touches part of your body that part of your body will be gone. There is NO time to get it off you.
(But the ozone layer will be just fine....)

.

[starfury1]

Re: attack of the dustbunnies

well I am told the recommend is vacuum it out with a vacuum thats designed for the job.

I am told compressed air blows crap into connectors sockets and chip pins etc.

me I use compressed air and haven't had a problem I know of
I am a bit careful with the first few hits to try and blow the dust away from things.

I've had a few like doods pass my way too...
think one of TC's willawake's or yantz posted here thats a real corker for dust
sorry dood makes yours pale in camparision.

but yours is a fine example of what we got to put up with

Cheers

[willawake]

Re: attack of the dustbunnies

this one?
https://www.badcaps.net/forum/showthread.php?t=1628

i would really like a vacuum designed for computers. the photocopy repair guy has one. usually i take things into the corridor outside the office and then vacuum up the remnants from the floor after using compressed air. if i was doing a lot of computer repair i would have one.....because compressed air cans are expensive.

[zandrax]

Re: attack of the dustbunnies

@ willa:
Next time you see the photocopy guy do watch if he wears a dust-stop mask: toner dust is thought to be carcinogenic, so better do not breathe it.
I once entered a small stationer's crowed with copy machines: the room ceiling was dark gray, not due to mould or cigarette smoke because it was a dry room and nobody used to smoke inside. I could smell the dust
Fortunately I did only once because my favourite stationery shop was closed that day.

Zandrax