How Do I Clean the Green Corrosion on the Contacts?

[alvin777]

Hi. This is the board of a digital caliper. It seem the contacts have been corroded by the PCB itself (green corrosion). What's this problem technically called by the way?

What product can clean it up? Will a contact cleaner work or is there another product that will work better? If it can't be cleaned with contact cleaner, if another product has to be used and I can't find the other product that you'll recommend, any homemade compound of solution I could make to clean it up? Thank you in advance.

http://i57.photobucket.com/albums/g230/alvin777/Any/DigitalCaliperBoard.jpg

Gbu.

 

[davenn]

vertigrease (spelling?) is one other name for it
contact cleaner will probably work, I use a flux remover, its cleans off all crud off a board

Dave

PS when you post pix somewhere like that reduce the physical size of the image makes it much easier to view if its 800x600 or 1024 x 768 rather than a huge blurry zillion x zillion

 

[alvin777]

Hi. Thanks for the reply. What caused the PCB to corrode to the copper contacts by the way? Contact cleaner isn't hard to find but I hadn't seen any flux remover in the hardware stores (no electronics store nearby either) but I'll look for it. Is there any way to make a homemade flux remover if I can't find one?

What's vertigrease? Is this the brand of the flux remover or the name of this type of corrosion?

 

[shrtrnd]

I don't know what CAUSED the green corrosion, but copper turns green as it oxidizes. I use isopropyl (spelling?) alcohol to clean off the boards. Is maybe the caliper being stored in some atmosphere that might promote corrosion? Or exposed to moisture which might hasten corrosion? Just something to think about.
On tough to remove oxidation, I sometimes use 'tuner lube', you can get from a store that supplies TV repair shops. GC Electronics made the last tube I got. I put it on a small brush or Q-tip, and it does a good job of getting the oxidation off. I don't know vertigrease, but it probably has the same effect. After I've got the oxidation off, I use alcohol or contact cleaner, to clean the work-area up.

 

[alvin777]

Thanks again. I visited a hardware. Which one have you used or could recommend among the three:

http://i57.photobucket.com/albums/g230/alvin777/Any/ContactCleanerRszd.jpg

 

[Resqueline]

The picture doesn't show any corrosion at all (it's too blurry), but I figure it could be caused by the high humidity where you live.
Anyway, you need a contact cleaner (spray) that says it removes oxidation (not only dirt/grease etc.). An oil residue would actually be beneficial.
Those solvent types (flux removers, isopropyl (rubbing) alcohol, no-residue cleaners) may work but so does the rubbing action of a wetted q-tip by itself.
Copper/brass polish could also do the job but you'd need to be very careful that the polish doesn't get anywhere else but on each individual contact.
The polish would then need to be cleaned off with a q-tip moistened with water. Make sure the PCB dries out completely before replacing the batteries.
I'm sorry but I don't know any of those (expensive) sprays.

 

[shrtrnd]

I haven't used any of the three contact cleaners you took the picture of. Read the labels, and find the one that meets your requirement. I specifically look for ones that say they're 'Safe For Most Plastics'. I had a friend who used a contact cleaner spray can on a clock/radio, and the overspray melted his plastic chassis housing.
As Resqueline says, you'll need to use a Q-tip. The rubbing action will be needed to get the corrosion off the board.
A foot note, it seemed like the can in your picture on the far left was for heavy cleaning, as in automotive applications. And the picture on the far right displayed integrated circuits on the label, as in electronic applications. Just read the labels, and make the best choice. (remember some Q-tips).