Vinegar rust removal, 19 months later
There are lots of ways to remove rust from metal. All of them have their tradeoffs: wire wheels can’t get in tight places, electrolysis produces explosive hydrogen, etc.
Vinegar is no exception. It’s by far the simplest process. You just dump your rusty junk in a bucket of vinegar and wait. But it takes a while. “The longer you wait, the better it works,” the greater Internet claims.
But both of those attempts seemed to leave some amount of rust that had to be removed after the fact.
Would an even longer bath be better? Or could it destroy the metal? I headed for my garage in the name of science to find out.
First, I sorted through my pile of old, rusty tools. The worst offenders were covered in a layer of powdery rust, making them unpleasant to use at best and unusable at worst. I threw those in a small trash can, submerged the tools in white vinegar, covered the can with some sealable plastic from the kitchen, and set the mixture off to the side in the garage. I figured I’d come back at the end of the summer and see how the tools fared.
Well, that was April 2015. In June of that year, I found out I was going to be a dad. This spurred a mad rush of projects at Reuter Acres. The house had to be painted, the carpet needed to be removed from the kitchen, the water heater needed to be replaced, etc. And that’s not counting the arrival of the kid. There wasn’t much time for frivolousness.
Here we are, 19 months later, and I finally got back to ye olde trash can. What would be left inside? Gleaming tools? Iron mush? Or something in between?
I turned on my camera, put on my gloves, and dipped in. Watch the video above for the full results.
For those who are stuck in whisper-only libraries, have terrible Internet connections, or just want more information, I’ll post some spoilers below.
What was left in the rusty vinegar?
Tools! They weren’t completely dissolved. But different items had different results.
First, I dug around in the bucket and pulled out all the solid pieces I could find. All were covered in rusty goo. I covered those in a baking soda and water mixture to neutralize the vinegar, then lightly scrubbed the tools to remove the mush. After a few rinse baths, I dipped them in Prep and Etch phosphoric acid solution from Home Depot to protect the tools from flash rust and prepare them for painting. After 30 minutes, I rinsed them off and left them on cardboard to dry. The next day, I sprayed them with Rustoleum Ultra Cover Satin Clear Spray, two coats on each side, and let them dry again for 24 hours. Now they were ready for closer inspection.
Most of the wrenches looked unscathed. The files were noticeably thinner, almost knife-blade-esque in spots. Some of the sockets had deep, empty pores on the ends. My friend Henry, a metals guy, saw similar results when doing this process with much stronger acid. He theorizes that those pockets already were rusted, but the rust wasn’t visible. The acid is drawn to the rust, eating it up all the way into the tool, leaving behind the spongy texture.
The most dramatic effect was apparent on a long, double-box-end wrench. It appeared as though one end had completely dissolved. I suspect that end was submerged in the rusty muck at the bottom of the bucket, exposing it to more destruction.
The most interesting thing to me was the vinegar’s effect on a small spring: It looked perfect. I would have thought that such thin metal would have been destroyed for sure. But the spring was enclosed inside a Duro ratcheting wrench, which must have protected from both the rust and the vinegar.
Would I do this again? I wouldn’t hestitate to use the vinegar-rust-removal technique for a shorter length of time, even a few weeks. But there actually are some interesting artistic implications for the long-term approach. The previously mentioned sockets, for example, are fascinating to look at. It might be fun to take a chunk of metal and half submerge it in the vinegar for an extended period of time to get a similar effect.
If you give this a try, let me know how it goes! Thanks for reading and watching.