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Tech Forum





February 2018

Neutralizing Battery Corrosion

What’s the best way to neutralize battery corrosion? I inherited an old, but expensive quartz watch from my grandfather and found a heavily corroded coin battery inside the watch case. I need to neutralize the corrosion without damaging the movement.

#2184
Clarence Dugan
Quitman, TX



Answers

Sorry Clarence but I suspect this is going to be difficult to impossible. I have used white vinegar to neutralize and remove the deposits and corrosion but:

  1.  The corrosion/battery acid and possibly the addition of the vinegar acid end up removing the coatings on metal parts which makes them less robust.
  2.  A watch has extremely small parts and the connections may be ruined already. You need to first take the watch completely apart to see the extent of the damage inside it. If the damage is confined to the battery port you may be in luck.

Use a Q-tip cotton swab with some vinegar on it; place it on the residue/corrosion and keep it there long enough to soak into the residue. Then twist the swab to remove the residue. If more removal is needed repeat this process. You can also use dry swabs to remove more residue if no more vinegar is needed.

Once all the residue is removed, you should use a contact cleaner/lubricator/protector fluid to coat the battery contacts.

Phil Karras, KE3FL
Mount Airy, MD

If the watch is really expensive, I would bring it to a watch maker shop and pay for the cleaning. At home, for my electronics, I use dish washing liquid — pour a few drops onto the corrosion and let it soak overnight. This usually dissolves the acidic corrosion. You can still clean with a Q-tip, then rinse and carefully dry the watch.

Werner
via Internet

Baking soda is a good acid neutralizer. It will stop further damage, but does nothing to restore damage done. The oxide already deposited will need to be removed with a scraping tool of some kind, and will without doubt, reveal damage.

Bill van Dijk
Canada

First, use a Q-tip and 90%+ isopropyl alcohol to clean the corrosion — do NOT immerse or flood the watch with alcohol! When you’re done with this step, CAREFULLY use canned air to GENTLY dry the cleaned area.

Then, apply a paste made from baking soda and water to the cleaned areas and let it sit for 20-30 min. The baking soda will stop any corrosive action by any corrosion not removed by the first alcohol cleaning.

Finally, use a dry q-tip to remove as much of the baking soda paste as possible, then finish cleaning any residue with q-tips and alcohol. Again, use the canned air to dry the cleaned area and ensure you don’t get any of the paste blown into the watch.

Take your time in cleaning and pasting — the leaked corrosion tends to be very tenacious, etc. and sometimes difficult to remove. Be aware that you’ll use lots of q-tips as you’ll want fresh ones when they get dirty and ratty.

Ken Simmons
Auburn, MI