Patina neutralising problems.

[doobriedoodle]

Hi everyone! I'm new to this forum and although I'm not generally a needy person I'm in urgent need of someones help at this moment in time
I have been working with silver clay for a little while now and, thankfully, I have managed to produce more successes than failures. However, I have come to the point where I would like to experiment with patina and have hit a brick wall. Every time I patina a piece and put it into the neutralising bath the process doesn't stop and the piece continues to blacken. I have tried bicarb in water and also baking powder in water but neither of them seem to be working for me. Pleeeeease could anyone advise me as to where I am going wrong.

[Dennis]

Hi,
It Would be helpful to know what patination solution you are using. It sounds as if you are simply going too fast because the process can normally be arrested under the cold tap.

Both ammonium sulphide and Platinol can be diluted with cold tap water so that the darkening process will be much slowed down and arrested in good time, showing the intermediate colours. It is also possible to suspend your piece by a thin thread in a closed box over ammonium sulphide for a more subtle effect, which you can check periodically.

For an antique look the highlights can be rubbed up with a silver cloth and the effect you achieve can be preserved for a time with wax polish. However the darkening does inevitably continue over some months due to pollutants in the air so that the long term result will be dark grey. Dennis.

[doobriedoodle]

Hi Dennis,
Thanks for your reply. I'm using XL GEL - liver of sulphur extended life gel. I diluted 1 tsp of gel in 350ml of cold water (as directed on the bottle) and painted it onto the chosen parts of my silver piece, when it reached the desired colour I plunged the piece into the bicarb and water solution. However, when I took it out of the neutralising solution not only did I notice that the patination process was not ceasing, but also that the rest of the silver had turned a pale gold colour. Thankfully I have managed to restore it to it's original state by putting it back in the tumbler for a couple of hours.

[Dennis]

Yes the pale gold is the very start of the patination process. The next stage is brownish, then a kind of blue. Try some scrap silver and dilute your medium with twice the amount of water, to slow it right down. If this fails, use ammonium sulphide solution, which can be arrested in cold water.

I doubt though that you will ever be able to place the colours accurately, because there is a chemical reaction involving a gas and the contamination spreads. The best you can hope for is to polish unwanted colours back again with a cloth or a retractable glass brush.

As with all techniques it is best to find out what a medium is capable of and then let it work for you not against you, Dennis.

[doobriedoodle]

Really grateful to you Dennis for sharing your wealth of knowledge with me, armed with that I will keep practicing on the vast array of scrap silver that I have. As they say practice makes perfect, I am the eternal optimist! Thanks again.