Jim, I recommend dissolving the phenidone and catechcol in propylene glycol (PG) as the "A" stock solution. Both chemicals will dissolve in PG around 160F to 170F. The resulting stock solution will last a for very long time. I mix 1 liter of the A solution at a time: 2 grams of phenidone, 50 grams of catechcol mixed in 800 ml of hot PG, then add PG for a total volume of l liter.

If you wish, you can prepare separate stock solutions of phenidone and catechol in PG.

I eliminate the metabisulfite, it is not needed with the PG as the preservative.

I mix a separate 2% stock solution of potassium bromide (KBr) in water: Dissolve 2 grams of KBr in 90ml of water at 125F, then add water for a total volume of 100ml. 10ml of this solution contains .2 gram KBr. Thus, you can add 10ml of the 2% KBr solution to 1 liter of the working developer.

The B solution and the mixing ratios remain unchanged (mix the B solution in water, not PG).

I recommend The Chemistry Store for propylene glycol: http://www.chemistrystore.com/