There may be a problem in mixing TEA with Glycol. Pyrocat-HD mixed in glycol remains clear for years. Pyrocat-MC, mixed in glycol with a small amount of TEA, darkens appreciably after one year, and more after two years. Other than the metol/phenidone difference in the two formulas, the only other difference is the small amount of TEA in Pyrocat-MC.
The fact that you mixed the 510 Pyro 1:1 with glycol may have accelerated the reaction between the TEA and glycol.
On the other hand, I have on hand a 510 Pyro solution that is several years old. It was clear for at least two years, but now has darkened considerably. It may or may not still be good, have not tested it with film recently. But as I noted earlier re: the darkened Pyrocat-MC, the fact that it is so dark makes me very suspicious that the reason is oxidation.
Originally Posted by Olli J