I have been working with metal salt solutions to color ceramic glazes and fluxes. I had problems with the low ph of the solutions being too aggressive on my application tools. This problem was solved by increasing the ph of the mixture before the addition of the metal salt with ammonium hydroxide. The metal salts were added until the ph of the mix was in the 6.5 range. The problem is that I seem to be losing metal concentration in the solution as the ph goes up. It was suggested that I could maintain to a certain degree the amount of metal in the solution with the addition of EDTA as a chelation agent. My friend also said that this would result in a more stable solution where the metal was less apt to drop out of solution.
Is there anybody out there who has any experience with stengthening and stabilizing salt solutions (specifically chlorides) with the use of EDTA?