Help me with my Shipwreck's assignment, plizzz......>_< (1 Viewer)

[whitymoon]

I got a prac assignment abt Shipwrecks, Corrosion and Conservation. This is abt i have to find different protections to coat iron nails to prevent corrosion. I have to do this prac at home and then give the result to teacher. I dunno what protection can i use (easy protection) so i can do it at home. I can do with painting, are there anything else?

Can someone help give me some idea? Thax.

 

[xiao1985]

cathodic protection? get a battery and link the negative to the nail?

 

[wrxsti]

Painting with zinc paint...... Painting with any paint...

 

[whitymoon]

cathodic protection? get a battery and link the negative to the nail?

In my exp, i have to leave iron nail in saltwater.does it have any affect when i do cathodic protection in saltwater?

 

[xiao1985]

shouldn't... cathodic protection should completely stop the corrosion process, whereas salt soln makes the corrosion process faster...

faster = no faster if there's no reaction...

 

[Serdain]

I'm not sure what nails you're getting but most these days are already galvanised so you have a form of protection right off the bat. Otherwise you could try passivating the iron... i'm not sure how long the layer takes to form, though.

 

[whitymoon]

thanks u guys so much ^^. I did do this exp with different kinds of metal : aluminium, copper and zinc. Can s.o. tell me the risk assessment of these metals. Thanks

 

[Serdain]

Copper doesn't rust past the surface, it'll get a green tarnish but that's about it. And aluminium and zinc passivate so you won't see any sign of corrosion (apart from the sheen becoming dull)... that is unless you're doing the experiment in sea water. If you are, the Cl- ions will interrupt the passivating layer and it'll rust.

 

[gscott]

I got a prac assignment abt Shipwrecks, Corrosion and Conservation. This is abt i have to find different protections to coat iron nails to prevent corrosion. I have to do this prac at home and then give the result to teacher. I dunno what protection can i use (easy protection) so i can do it at home. I can do with painting, are there anything else?

Can someone help give me some idea? Thax.

Wrapping some zinc around a steel nail to simulate cathodic protection - zince could be obtained from an old dry cell battery case - cheap batteries have thin zinc that can easily be cut with scissors, a little petroleum jelly will simulate an oil coating. Place the nails in a salt water solution and use a untrated nail as a control.

 

[xiao1985]

note however, cutting up battery can be quite dangerous...

 

[Serdain]

edit - I was wrong