Here is a post from an AMACO engineer on this subject.
and here is the thread it is from....Anyone Use Amaco Potters Choice Saturation Metallic Or Gold?
Palladium and Saturation Gold Users,
My name is Steve Lampron and I am the ceramic engineer here at AMACO. I want to give some simple tips about firing the Palladium and Saturation Gold glazes.
Palladium: This is what I call a float glaze. This means that in order to get the shiny silver look you need to actually allow the supersaturated metallic particles to float to the surface and form the skin. There is no trick to this other than to make sure you put a good thick layer of glaze on the piece. This is true of many glazes (commercial and made at home) which need a good thickness of glaze in order to make the surface. If you do not put enough glaze on, you will not have enough excess material to float and the glaze will look totally wrong. In the case of Palladium, it will be a fairly ugly green color. We fired this glaze on all of our clay bodies at both cone 5 and cone 6 with great results. I have a caution; this glaze can be very fluid and run so make efforts to allow for this. When you first try glazes you need to run test tiles (pieces) that are fired vrtically where you vary the thickness from what you think is too thin to what you think is too thick. This will show you where to go to get the look you want, it will also show you what it looks like when it is wrong. You will then know what went wrong when you get a pot that looks wrong. This glaze will be fine at cone 5 or 6 and requires no soak (it will make it run more). A medium / 8 hour firing is good. Cool normally. I see that a few people have gotten some blisters on pots that are fully glazed. This has happened on some clay bodies I found out after releasing it. It never seems to happen on poecelain bodies and these will also give the best surface. Please try your pots again on porcelain.
Saturation Gold: This is also a float glaze so thickness is important as well. The glaze doesn't turn out a bright shiny gold like gold lusters or the old leaded cone 05 golds. It turns out a dark kind of wrinkled bronze gold. It is not an easy glaze to get to look smooth and perfect. The suggestion that applying it over another glossy mid-range glaze is something that I find also helps the surface. The plain fact of the matter is that this type of glaze is difficult to use and requires alot of trial work. The kiln Gods probably didn't want this type of glaze to be made. It can be beautiful when perfected but it is not as simple to perfect as a pretty little matte white glaze.
I can't stress enough how important it is for all potters (especially new ones) to test glazes well before making pots. I know the desire to just make a pot but this method will only lead to disappointment and bad pots. Let me know if this helps or if I can address any other concerns you have.