Rescued some cast iron pans, here's the before and after for rust removal.
Turns out the "old timers" trick of scrubbing salt on it using the cut end of a potato really works! (It also worked using salt and a paper towel, but the potato was actually easier to hold)
Still needs some work but it's a huge improvement.
@grendel84 I once had to derust about 20 handplanes that were made mostly of cast iron. Given the amount of work, I went for a chemical solution and used one described in this video:
https://www.youtube.com/watch?v=fVYZmeReKKY
It became my go-to way of derusting any steel, and it is super cheap too. For each liter of water, mix in 100g of citric acid and 40g of washing soda. It will bubble like hell (producing hydrogen), but once it settles, it's ready to use. Just dunk the pan inside for 20-30m and check, if it is still rusted, soak for another cycle.
It doesn't attack the iron, just the iron oxide, unlike most of other solutions, and it lasts for many weeks of use.
@rafa Ah cool!
I actually think I still have both of those ingredients, as they are also used in home made black and white film developer. Chemistry is cool!
Thanks a ton 🙂
@grendel84 nice! You can also replace the washing soda with either baking soda or caustic soda, but the quantities are different and I don't remember, the video shares it.
Some rust may still be somewhat attached to the pan, but with a single stroke of a steel wool, it will come off, so I recommend that afterwards. Follow it by drying (with a heat gun or hair dryer) and oiling, immediately after taking it out of the solution, since cast iron will rust super fast when wet.
Hope it helps you out! Chemistry is awesome. I haven't used citric acid or washing soda for developing film, but I'll look into it and give it a try 😁
@rafa It's called caffenol, and uses instant coffee as the primary ingredient
Grendel
Rafa