Strip Zinc with Citric Acid
Sorry zinc, I am not attracted to you. Yes, you keep the elements at bay, but your non-stop shiny countenance is irritating. It looks out of place on my traditional projects. And you do not age well.
Zinc, it’s over. I’m going to go get me a stripper.
There are lots of ways to strip zinc, but most of them (fire, hydrogen chloride) are toxic or have an element of danger. Not so with citric acid. This weak organic acid is safe enough to dunk your hands into (though you will feel a sting if you have any open cuts). It’s safe enough to pour down the drain. And it’s fairly cheap. (It also can strip rust from your old tools.)
It’s easy to use. Take a bucket and pour enough water in there to cover your hardware. Pour about 1/2 cup of the citric acid powder in there for starters and stir the hardware and powder up. Wait a few minutes to see if the reaction begins. After 10 minutes you should start to see significant bubbling. If not, add a little more acid.
It takes about 30 minutes to strip the zinc off fasteners, which have a thin coating. Hinges usually take a little longer. And stuff that is intended for heavy-duty outdoor use can take overnight.
When the zinc is gone, remove the hardware and dry it. I shoot it with a little WD-40 or some oil. Pour the citric acid solution down the drain and you are done.
I used this process on the hardware for the home-center tool chest I built for an upcoming DVD with Popular Woodworking Magazine. Read about that here. Want to read about my experiments with hydrogen chloride as a stripper? Click here.
— Christopher Schwarz
P.S. The music in the video is Chatham County Line. You can find it at FreeMusicArchive.org.