Platinum/Palladium Chemistry Options
I wanted to talk a little bit more about some of the coating techniques for the other types of chemistry we could be using. So we've got the Na2 method we've been using. Which has our ferric oxalate number one, our Na2, 5% solution. And then our palladium solution number three. If you're using the traditional method, so you were gonna not use the Na2 solution, and that's the only thing that makes it the not traditional method, is you're gonna not use the Na2 solution, you're gonna use the ferric oxalate number one, and you're gonna use a ferric oxalate number two solution. The ratio, like I said earlier, of those two sets of chemistry, deal with how contrasting the negative would be. For your digital negative, you can pick whatever ratio you want. You could do, three parts A, to four parts B, and then seven parts of C, or part three. The key, if you're gonna use the other method, and if you're gonna experiment with the other method at all, is you still have a one, and now you have a tw...
o, and then you have a three. So you have part one, part two, and part three. Luckily, if you get it from Bostick & Sullivan, they actually label your jars, one, two, and three. So even though you don't even have to remember the name of the chemistry, you just have to remember one, two, and three. It is the total drops that are used in solution one and two, have to equal the total number of drops for solution three. So if you're gonna use, if you need 40 total drops, say you're coating the surface, you're gonna be doin' an 11 by 14, you need 40 drops, you would use, and you're gonna use a middle contrast, you'd have 10 of number one, 10 of number two, and 20 of number three. 'Cause those numbers have to stay in balance. You could use five drops of that, 15 drops of that, and 20 drops of that, because that's what changes, the ratio of these two is what changes your contrast. But these two, no matter what ratio they're in, have to match number three. Now I have the platinum solution here. Platinum is also a number three solution. So even if I swap out palladium for platinum, if these are 20, that's also 20. If I decided I want to mix these two, if these are 20, the total of these two are 20, so it's not 20 and 20. It's just one and two added together, equals the drops of three. If that ratio gets off, your chemistry gets off, and your prints won't look great. So that's the biggest piece you're gonna be working on if you get the traditional kit, or the standard kit. When you order up a kit using the traditional method, you have to usually specify and tell them how much of the ferric oxalate number one and the ferric oxalate number two you want. And the number two has the contrast control agent in it. And so you can basically say, I need 25 milliliters of each, or 50 milliliters of each. When I'm buying and doing traditional methods, I always buy an equal part of one and two. Because I'm gonna be using them probably in the long run, they will balance themselves out in the ratio. You won't have a number two in the kit we get. So, the kit we'd order up, or if you're gonna order a digital negative kit from Bostick & Sullivan it won't have the number two solution in it, because that 5% solution is basically replacing this. There are a number of charts you can use for figuring out the density, and they're actually very specific too, if the negative density range is between 0.6 and 0.8, you would use four drops of one, and six drops of number two. Or it's 12 drops, and zero. The charts are there with the actual very specific density ranges. So that information you can get online. I didn't include that in the session, because it wasn't specific to digital negatives. But it is an important part of that process. (sighs in relief) I forgot I had the buzzer off. I about had a complete freak out about the time there. I get so excited talking about the chemical part I wasn't paying attention to time. Okay, the other big thing about the chemistry is the platinum and the palladium, I think technically has a shelf live of 50 years, because you can't say longer than you're be alive in marketing materials. But for the most part, the platinum, and palladium solutions, almost an indefinite shelf life. They're incredibly stable. They're noble metals, so they're not gonna degrade over time. The solution stays active. The Na2 has an incredibly long shelf life, 'cause platinum is at it's core. The ferric oxalate number one, and the ferric oxalate number two, do have a shorter shelf life. So their shelf life's about a year, to a year and a half, on average. And it's hard to say. So for some people, it might be nine months. How people store their chemicals will make a big difference in that. How hot is it? How cold is it? How often is the chemistry used? All those little things are variable, plan on about a year. So when you get your chemistry in, if you're a person who doesn't use it all the time, and I think I don't have dates on these, 'cause I've been going through platinum chemistry like crazy lately. I basically come in, and when the chemistry first comes in, I'll just tag it with a date, so I just know what month it was appeared, and when it was going to expire. The thing that I do, 'cause I don't like to throw things away. And I'll tell you how to test for the ferric oxalate expiration here in a second. But once the ferric oxalate expires, I just basically put a piece of tape on it, so that I know that bottle's expired. But then, what I do, is I use the expired ferric oxalate for coating practice. So once I know that it's no longer good chemistry, rather than just get rid of it, I actually take my brush out and then that's a way for me to continue to practice with chemistry that was worthless, but I don't have to buy anything new, and I don't have to worry about the plating being in it. The only thing if you're gonna do that, just know that the coating color is not gonna be right, because it's missing the platinum or palladium, so it's not gonna have that great, beautiful amber orange color to it. But it's a good way to practice. So before I make the print, to test the ferric oxalate solution, you can basically coat a little bit of a paper with it. And then put it in the EDTA. And then agitate it for about four to five minutes. It should disappear. If it stays as a gray, kind of ghosty gray chemical look on the paper, then it's expired, it's processed itself out, and it's not able to be fully cleared. So, that's a quick little test for it. I've never really run into the problem of having the ferric oxalate not be useful, like I said, about a year. It's the one chemical that I don't buy a huge volume of, I buy enough for, like, six months, eight months, and then if I'm starting a platinum project, then I might buy a large volume. A number of years ago, I did a gallery show, and it had 22 platinum prints in it. So for that, I literally ordered up hundreds of milliliters, because I knew I would be going through a lot of chemistry. But other than that, you can get the chemistry shipped to you on a really easy, regular basis. So I don't store up huge volumes of the chemistry.