Pyrocat-HD has Metabisulphite and Bromide which might not dissolve in TEA unless you use very high temperature. However, Metabisulphite and Bromide can be left out of the formula by using Ascorbic acid - take a look at Pyrocat-HDC formula. IIRC Sandy King, the inventor of Pyrocat developers, has found that for all practical purposes, Pyrocat-HDC is same as Pyrocat-HD. Also look at Gainer's Cat-P-TEA formula, inspired by Pyrocat-HD, which uses only Catechol, Phenidone and TEA. No water needed in either Pyrocat-HDC or Cat-P-TEA.
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