How to galvanize metal (for rust protection)

video How to galvanize metal (for rust protection)

We show you how to galvanize metal objects to protect them rust.

First we get 30g of zinc sulfate and dissolve it into 100mL of water.

Zinc sulfate was made back in our video on making a copper sulfate and
zinc battery: http://www.youtube.com/watch?v=Id3tL2iI0Vw

Then connect the item you want to galvanize to the negative terminal of a 5 volt power supply. Connect the positive terminal to a strip of zinc metal.

Zinc metal was obtained from our video on getting useful materials from batteries: http://www.youtube.com/watch#%21v=knc1lSupAwQ

Immerse both electrodes into the zinc sulfate solution and keep them from touching. Then turn on the current and run it for about one minute to give the metal a zinc coating.

Remove the object and now it's galvanized.

To test the rust protection, place it on top of a paper towel soaked in saltwater. You should also place an unprotected item next to it for a good comparison. Cover the towel to prevent evaporation and wait a day or two.

The treated object should remain rust-free, perhaps developing a white crusty coating. The untreated object should start to rust.

darkroad says: Jan 4, 2013. 10:42 PM

i didn't see the videos. the plate on positive contact, what kind of metal did u use?
can i use any galvanized metal?

cowscankill says: May 31, 2010. 8:07 PM

Awesome! Would it be in my best interest to galvanize homemade knives, like machetes?

tom731109 in reply to cowscankillNov 2, 2012. 1:33 PM

Never galvanize any eating utensils as there are electro-chemical processes involved when in contact with foodstuff. This gets aggrevated by heat, be CAREFUL!!!

NurdRage (author) in reply to cowscankillMay 31, 2010. 11:55 PM

hmm, i don't know enough about the proper maintenance of non-stainless knives to really answer that question. Might be better to get information from sources dealing with smithing and similar trades.

cowscankill in reply to NurdRageJun 1, 2010. 5:02 AM

I'm sure the zinc would come off of the cutting edge the fastest, but the rest of the blade would be protected... might be wrong, but some protection is better than none.

servion in reply to cowscankillDec 6, 2010. 4:47 PM

You could just cover the cutting part of the blade during the treatment with tape, then remove it after. Most of your blade would be galvanised and the cutting edge would too, "thanks to the negative charge", as the author of this instructable would say.

nosnebp says: Oct 23, 2010. 2:09 AM

Excellent instructable, will try this out for myself. @rimar2000 will also try your idea. sounds good for larger objects, will try it and see what happens. Thanks again

sniperHunted says: Oct 18, 2010. 10:58 PM

is it possible for the zinc to react with the object its galvanizing?

DIY Dave says: Jun 1, 2010. 6:51 PM

Where can I get a strip of zinc from? Are any coins made of zinc? If so would they work?

NurdRage (author) in reply to DIY DaveJun 1, 2010. 8:47 PM

the link i put in the description doesn't work?

DIY Dave in reply to NurdRageJun 2, 2010. 10:01 AM

oh...sorry I guess I overlooked that.

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mikeasaurus says: May 31, 2010. 7:00 PM

Neat! Is there a limitation to the size of an object to galvanize, provided you have enough power and large enough vessel to immerse the iron?

(sweet microscope too!)

NurdRage (author) in reply to mikeasaurusMay 31, 2010. 11:03 PM

i suppose if things get really big, like an aircraft carrier, you're better off using more advanced rust protection techniques like cathodic protection and sacrificial anodes.

For one, i don't think it's easy finding a zinc strip as big as your aircraft carrier to serve as the positive electrode :)

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mikeasaurus in reply to NurdRageJun 1, 2010. 8:53 PM

I'll keep it in mind the next time the Nimitz makes port. How about something more like a hacksaw blade or door hinges, would 5V work or would you need more power / time?

NurdRage (author) in reply to mikeasaurusJun 1, 2010. 8:56 PM

like i said, cathodic protection and sacrificial anodes.

But if you're just galvanizing smaller items like doors than you can use the same 5v. but you need a power supply capable of delivering tens to hundreds of amps. and you need to place large anodes in a circle around the item.

Sl0whand says: Jun 1, 2010. 9:53 AM

Hey!
Thank you so much, not only for the detailed information on the subjects you deal with, but for opening si much opportunities to intelligence...

Thank you again.

R.

rimar2000 says: May 31, 2010. 6:52 PM

Thanks for the instructable, and specially thanks for the captions!!

I have galvanized iron objects using a plastic paintbrush soaked in zinc chloride, connected to the negative terminal of the car battery charger, and then "painting" the object, connected to the positive terminal. It is awesome!