[Borek]

Thin layer of sulfide. Color visible is IMHO due to the same effect you see when there is a gas drop put on the water.

Gaseous hydrogen sulfide will be probably most effective. Look for thioacetamide, it decomposes when heated and produces H₂S.

[jamesslack]

thank you very much i will try to buy some.

[jamesslack]

i think i found it,THIOACETAMIDE, REAGENT, ACS - 25 GM  would this be it.

[Borek]

Name sounds correct. Put a little bit in water, and heat - it will hydrolize and stink as hell.

[jamesslack]

i thank you again, i have been working on this for months now.

[jamesslack]

also do you need to wear a gas mask when turning this into a gas. or just be in a well ventilated area

[MarZ]

From my side I can confirm that SOdium Hydrogen Sulphate solution cleaned the coin nicely but did not form the colourful effect.  At the beginning of the thread it seemed you wanted to clean coins with some mild form of Sulphuric acid.  I agree with Borek's suggestion and precautions. If at home, I would try this under ventilation extraction over cooker/oven at your kitchen (if you have one), else outdoors.

[Borek]

Outdoors, or in some half open structure. You don't want to smell hydrogen sulfide at home.

Note, that hydogen sulfide is treacherous - it stinks like hell in lower concentrations, but it somehow paralyzes (in the lack of better word in my English) the nose cells in concentrations in which it is really dangerous.

But then, using just a pinch of thioacetamide, you are on the safe side. Just remember to either warn your neighbors or try it far from the buildings

[jamesslack]

the thioacetamide i got does not smell like rotten eggs or is there a smell to it, would this be a bad batch. i put some in a jar and i will let set for acouple of days to see if i get toneing on my silver coin. i put water and thioacetamide in a test tube and heated it up so the steam would go up the hose and into my other jar with the coin init. but the first time i tryed it i let the jar set for a day and tooked the lid off and there was no smell at all. heres a picture of the bottle that the companie sold me.

[renge ishyo]

You shouldn't be sniffing chemicals 

But yeah, according to the MSDS, thioacetamide has a very mild smell.

[jamesslack]

on my old post that i listed which is 12 post below this one hydrosulfuric acid i was told it would stink very bad that's why i thought maybe i had something that wasn't working.  boy i really wish i was a chemest so i would know all this stuff.  sorry for bugging you chemest.

[jamesslack]

i was also told i could make the H2S gas with black salt sulfur and a toilet bowl cleaner called the works but you got to use 2lbs of the salt and five bottals of the works which is way to much stuff to mix to tone a coin, but i think making it that way is way to dangers.

[renge ishyo]

Oh i see...you should have just replied in that thread; it would have bumped it to the top and helped with the clutter 

Yeah thioacetamide itself doesn't stink, but it releases H₂S which smells like rotten eggs (and is extremely toxic so don't breathe in much and make sure you do this in a place with good ventilation).

It is hard to tell from your setup if the H₂S didn't react with your coins already which would explain why you didn't smell anything after a day or so. To test for the quality of your thioacetamide I suggest following Borek's adivice by taking a tiny amount of thioacetamide and dissolve it in water (no fancy appratus), and heat it up on it's own out in the open air to test for the production of H₂S fumes. Once you smell that, immediately cut the heat because you know it is working. Then once you know it is working, proceed to the coin setup afterwards.

[Borek]

Just heat it up in water, it should start to stink.

Edit: I have merged topics.

[jamesslack]

well i tryed the thioacetamide to tone my coins but it did not work. but i did come across something that does give me the colors that i want but the colors are very light. heres a picture of a coin that i put in salt water and added current to the water. i guess they call it anodizing. is there anything i can add to my salt water to make the colors stand out more, any info at all would help and i will try what ever you say that migjt help. heres the picture