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Topic: hydrosulfuric acid  (Read 42134 times)

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Online Borek

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Re: hydrosulfuric acid
« Reply #30 on: September 30, 2009, 03:14:40 AM »
Anodizing means using coin as an electrode. If you have just put it into the bath it is not anodizing.
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Offline jamesslack

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Re: hydrosulfuric acid
« Reply #31 on: September 30, 2009, 09:35:30 PM »
no i put the coin in the salt water then put the + wire on the coin and put the - wire in the salt water and the coin turned with nice colors but they are very light. i was wondering if there was a way makeing the colors brighter some how. with another type of salt or something or some kind of chemical.

Offline renge ishyo

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Re: hydrosulfuric acid
« Reply #32 on: September 30, 2009, 11:44:09 PM »
You might want to try heating the discolored coin followed by super quickly cooling it i(probably using dry ice). I know that this is done with certain metals such as titanium to obtain different color patterns, but I don't know if it will work with impure silver. Be sure and try it with a "sacrificial coin" and not a precious one to see how it works  ;)

Offline BluRay

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Re: hydrosulfuric acid
« Reply #33 on: October 01, 2009, 10:35:51 AM »
no i put the coin in the salt water then put the + wire on the coin and put the - wire in the salt water and the coin turned with nice colors but they are very light. i was wondering if there was a way makeing the colors brighter some how. with another type of salt or something or some kind of chemical.
You can try with higher voltages or adding some oxidant as hydrogen peroxide, persulphate, ecc., ecc.

Offline jamesslack

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Re: hydrosulfuric acid
« Reply #34 on: October 01, 2009, 07:22:54 PM »
thanks,   you guys have been alot of help.

Offline jamesslack

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Re: hydrosulfuric acid
« Reply #35 on: October 01, 2009, 09:33:27 PM »
i will try the dry ice, but will have to fined a way of heating the coin up with out turning it colors by the heat. i think i know a way.

Offline renge ishyo

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Re: hydrosulfuric acid
« Reply #36 on: October 01, 2009, 10:38:59 PM »
Let me know how it goes. I was told how to do this with certain metals by a Jewelry maker believe it or not.

Offline jamesslack

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Re: hydrosulfuric acid
« Reply #37 on: October 01, 2009, 11:02:31 PM »
i will let you know how it works, im getting real close to getting what i want. heres a picture of one with the see threw light colors and dont hide the coin its self.

Offline renge ishyo

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Re: hydrosulfuric acid
« Reply #38 on: October 02, 2009, 12:38:26 AM »
That is really close. Now you just need a way to manipulate the color so you can control the pattern.

Offline jamesslack

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Re: hydrosulfuric acid
« Reply #39 on: October 02, 2009, 11:57:42 PM »
the dry ice did not change the silver color,

Offline renge ishyo

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Re: hydrosulfuric acid
« Reply #40 on: October 03, 2009, 01:28:22 AM »
The dry ice in and of itself wouldn't be expected to change the silver color...it is merely a cooling agent so that you can supercool a heated object very quickly by placing it in contact. The heating technique is one way to get metals to display certain colors, but I am no expert on the subject so I will leave it at that. I've been poking around and you may want to check out this book at your local library:

http://www.amazon.com/Coin-Chemistry-Weimar-W-White/dp/0971392498

It apparently has a decent essay on silver toning of coins that might prove useful to you. I'll poke around and see if I can come up with anything else.

Offline jamesslack

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Re: hydrosulfuric acid
« Reply #41 on: October 03, 2009, 09:23:17 AM »
i did heat the coin frist before putting it on the dry ice to cool it quick. yes the coin chemistry book i have thats why i was wanting to know how you could make h2s gas. but i tryed it too by useing thioacetamide, then tryed a house hold cleaner with black salt to make h2s but it only made my coin black.

Offline BluRay

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Re: hydrosulfuric acid
« Reply #42 on: October 04, 2009, 08:28:55 AM »
Sorry, but I haven't understood if you have already tried to heat the discoloured coin in dry conditions in the presence of a little H2S gas (this should produce sulfide layers on the coin).

Offline jamesslack

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Re: hydrosulfuric acid
« Reply #43 on: October 04, 2009, 11:01:09 AM »
i tryed to make H2S gas with thioacetamide, heated the thioacetamide up with water added to the  thioacetamide in a test tube with a cap on test tube with a hose running from test tube to another jar that the coin was in. i let the coin set in that jar for 24 hours, i also heated the test tube up intil all the thioacetamide was gone. but it didn't change the silver coin. i also tryed to make H2S gas with black salt and a drain cleaner called the works because it has alot of hydrochloric acid in it. but it made my coin black. the hydrochloric acid pitted the silver. the next thing i want to try is sodium sulfide with another type of acid to make the H2S gas. i need a acid that wont pit the silver when i turn it into a vapor gas.   if you know a acid that i can mix with sodium sulfide to make H2S gas that isn't like hydrochloric acid.   but there aging I'm getting what colors i like with anodizing with different chemicals i found to use with it.

Offline jamesslack

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Re: hydrosulfuric acid
« Reply #44 on: October 04, 2009, 11:03:23 AM »
same pictures  different angle

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