Steel wool best for corrosion removal?

[Dog Cow]

As you can see by this pic the inside of this GS has some rust and other corrosion, so my question is: what should I remove it with? Is steel wool the best option? Or is there something else better?

 

[Danamania]

If you do, take *everything* electronic out, use the steel wool to clean only the components with rust on them while they're removed from the case, and wash them thoroughly before putting them back together.

Steel wool breaks up, and makes wonderfully conductive short steel fibres that stick to everything!

Dana

 

[Dog Cow]

Thanks for the tip!

 

[Charlieman]

Steel wool is just an abrasive. Why not use glasspaper or sandpaper? The residual grit still needs to be washed away, but it is far less conductive than steel wool.

 

[porter]

If we are talking about rust then use a light oil to clean it off. Oil and an old rag.

 

[Charlieman]

What gets rusty in an old Mac or IIgs? RF shielding and power supply cases, surely? The metal chassis doesn't tend to rust unless it is very badly scarred and stored in a damp environment.

In my experience, RF shielding can get pretty rusty. I've never seen it perforated, but I've seen non-trivial rust. Wiping it with an oily rag is not sufficient.

 

[Bunsen]

There is indeed something better, and it's designed for the purpose. It looks just like a toothbrush, except the brush bit is made of brass (or copper?) wires. I can't recall whether I picked it up from an electronics shop, a hardware store or a car repair place, but it's made for corrosion removal and cleaning. Dana's tips above probably are still good, but IMHO you're much less likely to leave bits in the machine with one of these.

Might have been the car repair place now that I think of it.

Of course, you realise with the washing comes the thorough drying before applying electricity, yeah?

 

[equill]

Copper, brass or bronze, depending on the hardness desired, but most often brass. If the rusted metal is the bright steel (which relies on its polished surface to resist rust) of the PSU's case, or of the RFI shielding that I could not see in your pic., follow Dana and Bunsen. A brass-wire brush will scratch the bright surface least, but use it only to remove loose/powdery/erupting rust. Don't try to get back to bright metal—leave some rust colour—and then stabilize the surface with a proprietary liquid (such as Kill-Rust, Neutra Rust, End-Rust) containing chromium salts, phosphoric acid and poly-(vinyl acetate), applied by rolling on with a cotton-bud (cotton tip). Some light rust must remain to take part in the chemical reaction, and the PVA provides a protective coat over the result. You may not like the resulting deep blue/black colour, but further rust should not develop. You could also just brush off the rust and rely on keeping the inside of the computer dry.

Steel that has been annealed, plated or galvanized with zinc (dull to bright grey in colour) should not be treated with the same solution. In this case, brush, water-wash, dry, and spray-lacquer the affected areas. The 'sacrificial' zinc layer has done its job; the resulting salts have been washed off, and the zinc cannot be replaced easily. Or just make sure that the metal stays dry.

de

 

[register]

…stabilize the surface with a proprietary liquid (such as Kill-Rust, Neutra Rust, End-Rust) containing chromium salts, phosphoric acid and poly-(vinyl acetate)…

Be careful not to apply the liquid to other surfaces than the rusted metal, as it might cause discoloration if not removed soon.