A Pencil Eraser Trick

A project log for The Devil is in the Details

A bag of tricks and instant hacks that may come in handy when doing electronics

rogeorgeRoGeorge 10/10/2015 at 21:464 Comments

If you find an oxidized contact, NEVER scratch the oxide layer in order to clean the contacts surface, or else it will ruin the contact.

Most of the contacts are covered with various thin metallic layers, in order to minimize the contact resistance and to protect against rapid oxidation. Any fine abrasive paper will scratch the metallic cover layers too.

The above picture is an example of two BNCs from the same cable. This cable is very old, and it was not used in the last 10-20 years. Look at the middle pin of the second connector. It's black because of oxides. You might say to get a new cable, but this is an expensive Tektronix cable, of about 50 USD.

Still, the middle pin of the first connector is shiny. That is because it was cleaned using a pencil eraser. Pencil eraser is extremely good at removing oxides without scratching. Also, pencil eraser is elastic, but solid enough, and can be bent and cut to follow the surface to be cleaned.

The following images are showing the steps to clean the second connector too.

After cleaning, both connectors are as shiny and as good as new.


David Galloway wrote 07/30/2022 at 10:11 point

The picture host (TinyPic) has ceased operations. Oh the rotting Internet...

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RoGeorge wrote 08/01/2022 at 19:18 point

Uploaded the missing pics here on hackaday io

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Yvan256 wrote 02/18/2017 at 04:48 point

It's also an excellent way to restore the edge connectors of ISA and PCI cards.

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Eric Hertz wrote 10/11/2015 at 08:45 point

Cool, Thanks!

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