One way to repurpose used oil....

[oj88]

Saw this on Youtube and tried it out myself.

Apparently, you can make nuts and bolts as well as relatively small pieces of metal rust-proof by fusing carbon on it. It's better than paint as it won't chip off once cured.

Of course, I had to try it out. I gathered a bunch of rusty and pitted bolts.



I gave it an acid bath to remove most of the surface rust.


After several minutes, I washed them off with a baking soda solution (to neutralize the acid) then rinsed with tap water.


They look very clean now but at this state, rust will quickly form (flash rust) if you don't put any coat on it.


Next up is torching them until they're red hot.

[oj88]

As soon as they're all glowing red, dunk them in used oil (I used old Diesel motor oil) on a metal pan. Don't use containers that can melt.... the bolts will be hot enough to burn through it. Also, be careful of the possibility of a flash fire. Don't panic, just be ready to cover up the container if and when that happens.


After a few minutes, fish out the bolts and soak up the excess oil with some paper towels. Caution, it could still be hot.


After cleaning and drying them off, the bolts would've been coated with carbon and will be impervious to corrosion. It also will not chip off like paint does.