Hi, my experience with Metol is that even if you go up to 300F, Metol will not dissolve in PG. On the other hand, Sandy and several others have reported success dissolving Metol in TEA at temperatures around 250F.Originally Posted by jdef
My experience with PQ-PG (Phenidone/Hydroquinone/Polyethylene Glycol activated with Sodium Carbonate) is that if the dilution is too great, PQ-PG becomes very inactive and increasing the amount of alkali doesn't help much. PQ-PG works ok at 1:1:100, at 1:1:200 its activity drops off a cliff.
I discovered this while making direct comparisons with PC-PG (Phenidone/Pyrocatechol/Polyethylene Glycol activated with Sodium Carbonate). The PC-PG combination retained its activity at much greater dilution levels than the PQ-PG.
I did not use either sulfite or KBr in any of this testing.