"Do not use solvents on electronic equipment"

Many instruction booklets for domestic electronic equipment say do not use cleaning solvents such as alcohol.

Is this advice given simply because they are trying to prevent possible marking of the plastic casing?

Or can domestic cleaning solvents actually damage the electronics inside in some way?

Reply to
Sammy
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It is my impression that they dodge the entire gamut of liability this way.

If you used alcohol under their good graces, and disfigured the appliance, or started it up and it caught fire, they would be liable.

It is your appliance...do what you wish, realizing that if you screw up, it is on your own account.

Reply to
<HLS

Alcohol and many other solvents degrade some plastics. This can not only ruin the external appearance, but could affect insulation properties if the material develops cracks.

Ben Miller

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Reply to
Ben Miller

In any case, alcohol is a pretty mild solvent to most electronic components and housings. Things like petroleum solvents are more likely to cause damage (eg. lacquer thinner) and acetone (eg. some nail polish removers) is rather likely to cause damage to plastics or to remove markings.

For the outside, a damp (NOT sopping wet) cloth, perhaps with a bit of detergent is the safest, but I've never seen alcohol damage anything.

Best regards, Spehro Pefhany

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Reply to
Spehro Pefhany

"Sammy" wrote in message news:Xns9789850A75F8A451E7A@66.250.146.159...

In my experience chlorinated solvents can instantly ruin certain plastics. You don't find much of that anymore since the tree huggers came up with their horse-shit about chlorine harming the ozone layer. I have washed down some circuit boards with "plastic safe" spray solvents, only to see the potting overlay dissolve into goo. One thing to remember about alcohol is that the stuff you buy in the market called "Rubbing Alcohol" is mixed with both water, and glycerin. The water is fairly innocuous, but the glycerin leaves a faint oily residue on things. Not exactly the best pre-cleaner for adhesives etc. Better to get friendly with your pharmacist and get some pure isopropyl alcohol from him. I think pure isopropyl is a regulated thing because it can be used in drug manufacture or something tlike that. Anyway, it raises an eyebrow when you ask for it.One thing you can try as a last resort on a non-functioning board before you trash it: Run it through your dishwasher in the top rack with about half the usual dish powder. Obviously this won't work when things like mechanical pots etc are incorporated, but I have restored otherwise non-functioning boards several times like that. There is a product called "Goof-Off" that is a really great solvent for removing the adhesive left behind by labels, and it will even dissolve dried latex paint fairly rapidly. You need to be very careful with it, and test the substrate gently before you use it on plastics etc.

Reply to
Long Ranger

On Fri, 17 Mar 2006 13:04:42 GMT, Sammy Gave us:

Alcohol isn't a solvent as it relates to the components on a Circuit Card Assembly (CCA), per se (it will solve fluxes). They are talking about reactive solvents like lacquer thinner, or benzene, or toluene, or other petroleum based solvents. Any of those in the family that would melt plastic parts. Another thing a solvent can and does do is get into the vents of an EL cap and screw them up. One has to watch for that as well.

If you have a bare CCA in your hands (mind proper ESD procedures) you can heat up some alcohol (90% or better) in a microwave and wash the board down, Or immerse it, then blow it off with air and you should see no residuals. You should also bake it out at 60C for a bit.

Most modern assembly facilities these days use "water soluble" fluxes, and if you have a good oven that has good temp control, you can wash a CCA with water (not if it has transformers on it) and then bake it out for an hour at 60C to dry the CCA and the PCB itself out.

The alcohol is what I use as it "dries" a lot easier, and requires much less baking time (15-30min). The reason I use it hot is so it doesn't attract water so much. Hot air gun even works if you are careful with it.

I wouldn't use any cleaners on an assemble product that has plastic housings, or places that can trap liquids.

I disassemble if I want PCB assembly level cleaning.

Reply to
Roy L. Fuchs

On Fri, 17 Mar 2006 10:51:15 -0500, Spehro Pefhany Gave us:

Most of the plastic used for cases on products will slowly "dry out" and degrade from the surface in, and as BM stated, can hinder the insulative performance of the case, even though it not all that likely. They can also discolor.

He asked about the electronics though. I spoke about cleaning the boards if in hand, but spoke against cleaning assembled products as there are too many places that can trap the cleaning liquid(s) used.

In any instance, care is needed to ensure that there is no liquids left behind when the task is completed.

Reply to
Roy L. Fuchs

On Fri, 17 Mar 2006 17:07:37 GMT, "Long Ranger" Gave us:

Nearly ALL plastics.

You're a goddamned retard. The ozone hole above Antarctica ALSO has with it a HUGE chlorine cloud, dumbass. BTW, that is a nearly TWO decades old FACT, proven by NASA and the Space Shuttle missions.

One should never attempt to clean a potted assembly with solvents. MAYBE alcohol, and a subsequent oven bake cycle.

If you are talking about a conformal coating, the above still applies.

Just water, generally.

When was this thread ever about cleaning adhesives?

Or order it from digi-key or mouser or E-bay.

Not! Still guessing, eh loner boy?

You're so full of shit, your eyes are brown, and there is a foul stench emanating from your ears.

Wrong! A few drops of LIQUID soap (saponifier), but NO powders as they can be trapped without ever "melting" into the wash.

Hahahaha. In the restoration business, eh? What if there are transformers on the board? Why no mention of a bake cycle to dry the board out? Are you new to electronics, ranger boy?

He never said a damned thing about a label.

Substrate? Do you mean "test an area not visible on the finished assembly"?

Reply to
Roy L. Fuchs

I believe that typical glass/epoxy circuit boards and most electronics components are generally resistant to most solvents. It's the housing around the electronics that's a bigger issue.

I've found a whole lot of things can damage the ABS housing used for lots of electronic components. I have a halogenated hydrocarbon tape head cleaner (perc). I've spilled sunscreen that's damaged the case of a Walkman - likely some silicone emulsifier. DEET insect repellent will eat through a host of plastics (esp clothing) including styrenes, polyester, and spandex, as well as rayon.

Reply to
y_p_w

Acrylic can be damaged by some of the more active solvents- cause brittleness and stress corrosion cracking (eg. where fasteners contact the material). ABS can be softened by a lot of solvents but it does not seem to suffer that kind of 'hidden' damage.

Best regards, Spehro Pefhany

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Reply to
Spehro Pefhany

I used to wear a certain brand of sunscreen that tended to feel great on the skin. My keyboard at work has these black areas that scrape off easily. It feels soft and sticky. Compact Disc jewel cases are another common item that will be affected by a host of solvents.

Reply to
y_p_w

CD-ROM jewel cases are typically acrylic for the clear part, and ABS for the opaque part. I think CD jewel cases might tend towards the cheaper polystrene for the clear part.

Best regards, Spehro Pefhany

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Reply to
Spehro Pefhany

Some cleaners can leave behind a slightly conductive residue that can affect very-high-impedance circuits in a bad way. Most drugstore isopropyl actually has a small amount of oil in too, and this oil can leave behind a thin film.

In general non-oil-containing isopropyl isn't so bad for most modern electronics.

But a note about more powerful solvents (acetones, other hydrocarbons):

Last summer I got a pair of prescription sunglass lenses put into a pair of Ray-Ban frames. They looked fine when I took them out of the store. But within a few hours, there were literally hundred of little hairline cracks on the surface. I head back to Lenscrafters, and by the time I get there the frame now is cracked into 5 or so pieces. I take a number, explain what's happening, and we watch as the frames are self-destructing in front of our eyes, literally falling apart into a bunch of little grey discolored chunks. They get me an explanation: the lab had used acetone to clean the frames after mounting the lenses, and acetone attacks this particular lightweight plastic in an awful way. Needless to say, I never clean this pair of glasses with anything but water anymore!

I had thought that generally modern plastics were more resistant to common solvents than older plastics. But the disintegration in front of my eyes changed my mind!

Tim.

Reply to
Tim Shoppa

There are several manufacturers of polypropylene CD/DVD cases. My personal favorite is DiscSavers. They don't crack and aren't affected by most solvents.

I'm baffled as to why polystyrene when it's well known that just looking at it funny causes damage.

Reply to
y_p_w

On Fri, 17 Mar 2006 17:56:15 -0500, Spehro Pefhany Gave us:

Polycarbonate, actually.

Whatever. got a link?

Polycarbonate throughout.

Reply to
Roy L. Fuchs

On 17 Mar 2006 15:22:44 -0800, "Tim Shoppa" Gave us:

The word for today is VULCANIZATION

formatting link

With rubber, it is a good thing. With plastics, it is usually a bad thing.Especially if they weren't meant to be that way.

Reply to
Roy L. Fuchs

1) It's really clear, so it helps sell the product 2) It's really cheap

Polycarbonate would be nice, but perhaps a bit expensive (and it scratches more easily than acrylic, and it's a bit yellow).

Best regards, Spehro Pefhany

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Reply to
Spehro Pefhany

I've had rubbing alcohol ruin the translucent red cover for an LED display on a couple of pieces of test equipment. Also, don't let the cleaning folks with their typical spray cleaners or furniture polishes anywere near stuff you want to see thru (VCR displays, etc).

Reply to
William P.N. Smith

I'd like a pointer to a source of polycarbonate cases.

Best regards, Spehro Pefhany

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Reply to
Spehro Pefhany

I wonder if this is there method to get you to buy from them again?

Reply to
Abstract Dissonance

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