Hello everyone,
In the past months I experimented gilding my plates and I now get acceptable results without burning the images. I am slowly getting to the bottom of the bottle with Gold Chloride that I originally bought for this purpose. The label on the 50 ml glass says that it is a 1% solution that contains exactly 0.5 grams of Gold metal and exactly 1.725% of gold chloride as HAuCl4.
There are now two questions that I have got about this:
1. Do I use it in the right ratio?
When I prepare a 4th plate I mix 20 ml gilding solution in the following way:
I prepare solution A by mixing 9 ml of distilled water with 1 ml out of my Gold Chloride bottle.
I prepare solution B by dissolving 4 gr Hypo in 500 ml distilled water. I usually keep solution B in a big bottle and take 10 ml out of it for each 4th plate.
Solution A has a quite yellowish color when mixed and the final gilding solution comes out clear when I pour solution A into solution B.
When I use the gilding solution on my plates it is giving the picture a slight golden tone, increases the contrasts and also makes it quite resistant against wear and tear. This is what I would expect but the question still remains if I am mixing Solution A in the right ratio.
The usual instruction to mix solution A is: ‘1 gram of Gold Chloride dissolved in 500 ml of distilled water’ which implies that the person who wrote this used Gold Chloride as a powder (AuCl3) which I could not get at the time. My calculation was quick and dirty and I am aware that it might not come out exactly right. So please correct me if I am wrong…
Using 1 gram of Gold Chloride on 500 ml of distilled water as explained in the usual instruction would mean a ratio of 1:500. According to the label on my bottle there is 1.725% of gold chloride mixed with 50 ml distilled water in it – ratio 0.8625:50. If I dilute 1 part of the bottle with an additional 9 parts of distilled water I get a similar ratio as 1:500.
Is this correct?
2. Where do I get the best prices for this?
I can get a bottle like the one I bought before for around USD 50 on ebay. I also contacted several suppliers for AuCl3 in China. One gram of the powder is around USD 95 there.
Due to a lack of knowledge in chemistry I am not able to calculate how many grams of AuCl3 powder the fabricator of the bottles mixed into the 50ml of distilled water. Not knowing that makes any price comparison hard. I was wondering if anybody could help out with this.
-Stephan