By Jim
Ok, I know what you’re thinking about here. Old Jim is off his rocker…. Maybe so but not in this case. When I have a valuable antique firearm, I clean it with a potato. Now let me explain — potatoes are naturally high in oxalic acid. And oxalic acid dissolves rust. So I go to the local grocery store and spend about .50 cents on a small spud. Russets are great for rust busting.
I’ll chop off a chunk of potato and coat the end with baking soda. This acts as a mild abrasive and does neutralize the oxalic acid a little. Remember — oxalic acid can be used as a bleach, and it’s a thousand times stronger than acetic acid (vinegar)
To get into tiny crevices that contain rust, I’ll cut off a few thinner slices of potato and crush them in a cup, and let the liquid settle out of the mass. Always use raw potatoes to clean with, because cooking destroys the acid.
I make sure to scrub as much as I can inside crevices, even using a bristle brush and a Q-tip to get it inside.
I use the sonic cleaning tank to soak the parts in and clean out the potato and baking soda. Mine has a heater feature that makes the water hot. I don’t recommend buzzing the ultrasound operation too much because this will remove the original finish. You want to do it just enough to get the cleaners out.
Here’s the breech block reassembled with the old firing pin and a new return spring installed.
Notice the before and after photos of the receiver cleaned with a potato. The neat thing is — once the rust is completely gone, sometimes the original color case hardening shows up again on the metal. The oxalic acid in a potato dissolves only the rust and nothing else. The original finish was there all along, just hidden under the rust.
You can see the color case again.
See the rust on the lower end of the mainspring ?
This is after scrubbing it with a potato.
Maybe scrubbing a priceless antique firearm with a potato is not so crazy after all. I don’t do this except with a high dollar item because it is pretty messy. But when you want to clean the gun and not get scratches in the finish or ruin the patina, try heading to your local grocery store next time.