A little while ago I was digging through my grandparent’s shop and I found an old hammerhead that was completely covered in rust and in some serious need of TLC. Other than the rust, the hammerhead was in excellent condition and just needed a new handle to become functional again. While I was holding this rusty project, I was reminded of a technique for removing rust that I had seen several times on youtube videos that I had always wanted to try. The technique was to soak the rusted part in vinegar for a few days, with the idea that the acid would eat away the weaker rust, and leave you with a rust free hammerhead. The technique didn’t seem too difficult so I decided to give it a try.
The hammer is an 8 lb. mallet head and so I knew that I would need a lot of vinegar cover the part completely. for this project, I went and bought a large container of regular white vinegar and a plastic container with a lid that would be big enough to hold the entire hammer without being so large that I would waste vinegar. The main process of this experiment was easy to accomplish as it just required that I submerge the hammerhead in the vinegar for an extended period of time.
The container that you see in this picture ended up not being waterproof which is why I ended up buying the new container, but here you can see just how rusty the hammer was before this process. I ended up soaking my hammer for about a week in the vinegar, however, the exact time depends on the amount of rust you are removing. if you just need to make the rust easier to remove and you don’t want to damage the metal than I would recommend soaking your project for only a few days, but if you need a deep clean than a week of a month may be more applicable. The longer you soak your project, the more material will be removed. A week worked well for me because it was at that point that the vinegar started to be discolored, which doesn’t have any effect on its acidity but at that point I was unable to monitor the acid’s progress anymore so I figured that it might be time to at least take it out of the vinegar and take a closer look. One interesting thing I noticed while checking the progress throughout the week is the number of bubbles that were forming on the surface of the hammer. each bubble was small, but there were hundreds of them and they were constantly rising from off the hammer. I don’t know what the bubbles were made of, but it was cool to look at.
By the end of the week, as you can see the vinegar had turned a muddy color and the metal already was looking much cleaner. The discoloration is likely due to the vinegar dissolving the iron oxide, or the rust, and so inheriting the reddish color as a result. what surprised me the most was what the hammer felt like after I took it out of the vinegar.
The rust came off in flakes so easy that you could remove it with just your finger, and the whole hammer was slippery. seriously, much of the hammer was covered in a slime of some sort that gave it a slippery texture which, coupled with the flaking rust and the 8 lb. mass, made the hammer surprisingly hard to hold on to. I must warn you that cleaning this hammer was a very messy process, but not for the reason that you would expect. While the vinegar mostly dissolved the rust, it also removed some of the iron and the result was a black residue that made a mess of the sink and scrubbers that I used.
If you try this process yourself, it would be a good idea to only use cleaning equipment that either is never going to touch anything that needs to be food safe or only use cleaning equipment that needs to be retired anyway so you can replace them after cleaning the rust. I don’t know if that black residue is food safe or not but I would rather not risk it.
This project turned out to be surprisingly easy to do and extremely effective at removing rust from unwanted metal objects. Above you can see a before and after comparison that I think says it all. One interesting side effect of using acid to clean this hammer is that left the surface of the hammer full of miniature holes, likely where there were imperfections in the metal that melted away leaving tiny holes in their stead. I hope you enjoyed this project, I learned a lot from it and really enjoyed playing with acid, even if it was only vinegar. good luck with your projects and Happy Tinkering!