inferno
( ͡° ͜ʖ ͡°) <*))))><
yeah there you have it. all good methods explained and tested on video. with science.
personally i have used hcl, acetic, oxalic, citric- acid.
my favorites are oxalic because its much much faster than than acetic acid (vinegar), and you can also etch/blacken **** with it, even stainless.
and 30% hcl. it gets **** done fast. you need to neutralize with some base afterwards though (like lye), because water will not stop the process.
now recently i have tried a rust "eater" which was 20% phosphoric acid in a gel. i used this inside a rusted steel bike frame.
and i'm very impressed with this product. it basically made the rust not stick to the part anymore so it could be flushed/washed away
and the surface it left was clean steel in color. not black. not dull gray, just clean freshly ground steel kinda. there might be more ingredients in this product though.
whats the other 80%?? i dont know.
in theory the phosphoric acid will turn the rust into inert iron phosphate. its used in "rust converters". also tannic acid is used in these. or a mixture of them. have not tried tannic acid yet.
there is also stuff they use in industrial processes, i rememeber reading of a mixture with citric acid and some other acid, dont remember which one.
and basically the stronger acid would do the heavy lifting and the citric would clean the surface. like some type of chelation process. and the parts would come out completely clean with no discoloration.
you might need to have a certain elevated temp for these to work optimally. like 70C or so. i dont know. it usually does though
