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Old 4th Apr 2019, 11:54 am   #29
ColinTheAmpMan1
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Location: Wimbledon, London, UK.
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Default Re: Rust removal from steel component on the cheap.

Quote:
Originally Posted by Bazz4CQJ View Post
Perhaps we should look at this from another angle. Rubbing down a rusty surface with aluminium foil will give you nice mixture of particles of rust and particles of aluminium and I suspect that some of you will now think of the term "Thermite". For those who don't know, Thermite is an extremely powerful pyrophoric mixture, consisting of powdered iron oxide and powdered aluminium which used with skill, can be used to either cut or weld large sections of steel, see https://www.youtube.com/watch?v=RXQnIgrXJd8.

Anyone trying this "rust removal technique" had best make sure there are no sources of ignition anywhere near! As iron oxide is so hard that it is used as an abrasive, and aluminium foil is more "soft as putty" ranking, this does not sound like a good rust removal strategy to me. Why not just use steel wool or stainless steel wool?

There's no 'magic electrolytic action' because there's no electrolyte!

B
I agree with a lot of this, but I feel I should repeat my statement that rust isn't just iron oxide, it is ferroso-ferric oxide and probably contains some other iron compounds such as hydroxides and carbonates. I think it might make a pretty poor Thermite mixture. The Royal Society of Chemistry web-site says that iron(III) oxide (ferric oxide) should be used. I should add that while I have made Thermite and ignited it in the same manner as m0cemdave stated, I have no direct experience of making Thermite by rubbing rusty metal with aluminium foil. I might be talking nonsense.

Colin.
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