I know Hf etches alot of materials, but I can't seem to find any information on how it reacts to Fe.

[ce]Fe + 2HF -> FeF2 + H2 ^[/ce]

I'm not a chemist so could you explain that to me? What difference would be made if i added hcl aswell?

I believe HF reacts quite vigorously with most substances except for perfluoroalkanes/polymers. HCl reacts with iron to give iron chloride and H2 gas, but this reaction is very slow. The iron is passivated by a thin layer of mixed iron oxides, meaning HCl has a tough time having good collisions with iron atoms. I once put an iron nail in a glass of about 40% HCl, it took at least a few days to observe any visible change.

I know HCL can be used to get rust off a nail, i was just wondering about if it was possible to use hf to get rid of the gunk that is resultant, its a solution of water and iron chloride.

Using HF will only leave you with iron fluoride gunk, which is worse. HF is some really nasty stuff, I would feel guilty reccomending its use to anyone unless it was absolutley neccessary for a synthesis. Try acetone, if that doesn't work, dilute sulfuric acid or dichloromethane might.

Removing iron gunk and rust might be best done with Phosphoric acid, which is much, much safer than HF. You can buy it at hardware stores in the form of a product caled "Naval Jelly" which can be applied to a rusty surface and after a while, Fe2O3 turns into FePO4 that can be easily wiped off leaving a shiny metallic surface!

 

Robert

Removing iron gunk and rust might be best done with Phosphoric acid, which is much, much safer than HF. You can buy it at hardware stores in the form of a product caled "Naval Jelly" which can be applied to a rusty surface and after a while, Fe2O3 turns into FePO4 that can be easily wiped off leaving a shiny metallic surface!

Robert

 

good call, should've thought of that one